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Wiebe, Peter N., Cameron J. R. Blimkie, Nathalie Farpour-Lambert, Julie Briody, Damian Marsh, Allan Kemp, Chris Cowell i Robert Howman-Giles. "Effects of Single-Leg Drop-Landing Exercise from Different Heights on Skeletal Adaptations in Prepubertal Girls: A Randomized Controlled Study". Pediatric Exercise Science 20, nr 2 (maj 2008): 211–28. http://dx.doi.org/10.1123/pes.20.2.211.
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Few studies have explored osteogenic potential of prepubertal populations. We conducted a 28-week school-based exercise trial of single-leg drop-landing exercise with 42 prepubertal girls (6 to 10 yrs) randomly assigned to control (C), low-drop (LD) or high-drop (HD) exercise groups. The latter two groups performed single-leg drop-landings (3 sessions/wk−1 and 50 landings/session−1) from 14cm(LD) and 28cm(HD) using the nondominant leg. Osteogenic responses were assessed using Dual Energy X-ray Absorptiometry (DXA). Single-leg peak ground-reaction impact forces (PGRIF) in a subsample ranged from 2.5 to 4.4 × body-weight (BW). No differences (p > .05) were observed among groups at baseline for age, stature, lean tissue mass (LTM), leisure time physical activity, or average daily calcium intake. After adjusting for covariates of body mass, fat mass and LTM, no differences were found in bone mineral measures or site-specific bone mineral density (BMD) at the hip and lower leg among exercise or control groups. Combining data from both exercise groups failed to produce differences in bone properties when compared with the control group. No changes were apparent for between-leg differences from baseline to posttraining. In contrast to some reports, our findings suggest that strictly controlled unimodal, unidirectional single-leg drop-landing exercises involving low-moderate peak ground-reaction impact forces are not osteogenic in the developing prepubertal female skeleton.
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Lee, Ha Min, Seunghue Oh i Jung Won Kwon. "Effect of Plyometric versus Ankle Stability Exercises on Lower Limb Biomechanics in Taekwondo Demonstration Athletes with Functional Ankle Instability". International Journal of Environmental Research and Public Health 17, nr 10 (22.05.2020): 3665. http://dx.doi.org/10.3390/ijerph17103665.
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Background: This study aimed to compare the effects of plyometric and ankle stability exercises on the dynamic balance and lower limb kinematic and kinetic parameters of Taekwondo demonstration athletes with functional ankle instability. Methods: Fourteen subjects participated in this study and were randomly divided into two groups: a plyometric exercise group (n = 7) and an ankle stability exercise group (n = 7). Exercises were performed twice a week for 8 weeks. A Y-balance test was used to measure dynamic balance, and a motion analysis system and force plate were used to collect kinematic and kinetic parameters during single-leg drop landing. A paired t-test was used for intragroup comparisons, and an independent t-test was used for intergroup comparisons. Results: In both groups, exercise increased dynamic balance and shock absorption and reduced postural sway on the anteroposterior displacement (p < 0.05). The plyometric exercise group decreased their ankle dorsiflexion and increased their knee and hip joint flexion at maximum knee flexion (p < 0.05). In contrast, the stability exercise increased their ankle plantar flexion at initial contact (p < 0.05). Conclusions: The plyometric exercise group altered their landing strategies using their knee and hip joints to control ankle instability at landing. This study suggests that the application of plyometric exercises in ankle rehabilitation would improve stability and shock absorption and help prevent injuries during Taekwondo demonstrations.
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Huang, Pi-Yin, Amornthep Jankaew i Cheng-Feng Lin. "Effects of Plyometric and Balance Training on Neuromuscular Control of Recreational Athletes with Functional Ankle Instability: A Randomized Controlled Laboratory Study". International Journal of Environmental Research and Public Health 18, nr 10 (15.05.2021): 5269. http://dx.doi.org/10.3390/ijerph18105269.
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Plyometric exercise has been suggested for knee injury prevention in sports participation, but studies on ankle plyometric training are limited. This study aims to investigate the change of joint position sense and neuromuscular activity of the unstable ankle after six-week integrated balance/plyometric training and six-week plyometric training. Thirty recreational athletes with functional ankle instability were allocated into three groups: plyometric group (P) vs. plyometric integrated with balance training group (BP) vs. control group (C). Ankle joint position sense, integrated electromyography (EMG), and balance adjusting time during medial single-leg drop-landing tasks were measured before and after the training period. Following the six-week period, both training groups exhibited a lower absolute error in plantar flexion (P group: pre: 3.79° ± 1.98°, post: 2.20° ± 1.31°, p = 0.016; BP group: pre: 4.10° ± 1.87°, post: 2.94° ± 1.01°, p = 0.045), and the integrated group showed a lower absolute error in inversion angles (pre 2.24° ± 1.44° and post 1.48° ± 0.93°, p = 0.022), and an increased integrated EMG of ankle plantar flexors before landing. The plyometric group exhibited a higher integrated EMG of the tibialis anterior before and after landing (pre: 102.88 ± 20.93, post: 119.29 ± 38.33, p = 0.009 in post-landing) and a shorter adjusting time of the plantar flexor following landing as compared to the pre-training condition (pre: 2.85 ± 1.15 s, post: 1.87 ± 0.97 s, p = 0.006). In conclusion, both programs improved ankle joint position sense and muscle activation of the ankle plantar flexors during single-leg drop landing. The plyometric group showed a reduced adjusting time of the ankle plantar flexor following the impact from drop landing.
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Vaishnavi, G., V. Saipavithra, G. Yuvarani, K. Kirupa, G. Tharani, S. Sathya i R. Vidhyalakshmi Vikram. "Effectiveness of isolated ankle strengthening and functional balance training in single leg drop jump land in football players and measuring the stability". Biomedicine 40, nr 3 (9.11.2020): 392–94. http://dx.doi.org/10.51248/.v40i3.36.
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Introduction and Aim: Football is one of the famous sports in the world and associated with many ankle injuries in football players. Many football players use single leg drop jump landing ranging from 13 to 20 out of 1000 players. Functional balance maintain or improve activities of daily living and quality of life. Strength training increases the density of bone and reduces the risk of fractures. Aim of this present study is to analyze the effectiveness of the isolated ankle strengthening and functional balance training in single leg drop jump land in football players.
Materials and Methods: 30 football players with single leg drop jump were randomly selected to participate in this pre and post test experimental study. Study is done at ACS medical college. Selected players were asked to perform the exercise for about 8 weeks, 40 minutes per day. The subjects performed ankle strengthening for 20 minutes and functional balance training for 20 minutes. Dorsiflexors are at high-risk injury during single leg drop jump land in football players. Thus, exercise is given for strengthening and functional balance and prevailing stability of ankle is measured using foot and ankle measure (sub scale) (FAAM), Star Excursion Balance Test (SEBT).
Results: On comparing mean values of SEBT within group between pretest and post-test values, it shows statistically highly significant difference and improvement in balance between pre-test (89.67) and post-test (94.18) at P<0.001. On comparing the mean value of FAMM sports subscale within group between pretest and post-test values, it shows statistically highly significant difference and improvement in ankle and foot physical function between pretest (45.34) and post-test (60.81) at P <0.001.
Conclusion: This study shows that isolated ankle strengthening, and functional balance training is effective in improving the ankle strength and balance in football players.
Keywords: Stability threshold; single leg drop jump land; foot and ankle ability measure scale sports subscale (FAAM); star excursion balance test (SEBT)
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Pirmohammadi, Narges, Elham Shirzad i Hooman Minounejad. "Effect of a Four-week Core Stability Training Program on the Kinetic Parameters in Athletes With Functional Ankle Instability During Single-leg Drop Landing". Journal of Exercise Science and Medicine 11, nr 1 (1.01.2020): 33–42. http://dx.doi.org/10.32598/jesm.11.1.4.
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Introduction: This study aimed to investigate the effect of a 4-week core stability training program on landing kinetic parameters in athletes with functional ankle instability during a single-leg drop landing exercise. Methods: This study used a pre-post quasi-experimental design and was conducted in the biomechanics laboratory. A total number of 24 athletes with functional ankle instability participated in two experimental (n=12) and control (n=12) groups. The experimental group performed core stability training for 4 weeks. The kinetic variables (maximum vertical Ground-Reaction Force [GRF], maximum shear GRF, and time to peak vertical GRF) were measured with force plate at the frequency of 400 Hz, in the pre-test and post-test. The obtained data were compared using Analysis of Covariance (ANCOVA) and multivariate analysis of covariance MANCOVA in SPSS V. 18. Results: In the experimental group, all variables significantly differ between the pre-test and post-test. Also, the ANCOVA and MANCOVA indicated significant differences between the experimental and control groups in all variables. Conclusion: The results indicated that the core stability training improved the kinetic parameters of landing in people with functional ankle instability; thus, it can reduce the re-injury risk of the ankle.
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Gray, Vicki L., Larissa M. Juren, Tanya D. Ivanova i S. Jayne Garland. "Retraining Postural Responses With Exercises Emphasizing Speed Poststroke". Physical Therapy 92, nr 7 (15.03.2012): 924–34. http://dx.doi.org/10.2522/ptj.20110432.
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Background Postural responses are impaired after stroke, with reduced or delayed muscle activity in the paretic leg muscles. Objective The efficacy of exercises emphasizing speed of movement in modifying postural responses to perturbations that were not practiced was investigated. Design This was a dual cohort design. Methods A convenience sample of 32 individuals with hemiparesis poststroke (mean number of weeks poststroke=11.3, SD=4.1) who were recruited upon discharge from an inpatient rehabilitation hospital and a control group of age- and sex-matched individuals who were healthy (n=32) performed a single session of exercise emphasizing speed of movement. To assess postural responses to internal perturbation, unilateral arm raise and load drop tasks were performed before exercises (pre-exercise), immediately after exercises (post-exercise), and 15 minutes after exercises (retention). The time to burst peak and area of the biceps femoris muscle (BF) electromyographic (EMG) activity in the arm raise task was measured with the arm acceleration and velocity of the center of pressure (COP) excursion. For the load drop task, the anticipatory EMG deactivation area of the BF was calculated. In both tasks, the vertical ground reaction forces were recorded for each leg separately. Results Before exercise, EMG and force platform measures were smaller in the stroke group than in the control group. After exercise, the paretic BF time to burst peak decreased, the paretic BF EMG area increased, and the COP velocity increased in the arm raise task, as did the paretic BF anticipatory EMG deactivation area in the load drop task. The stroke group was weight bearing more symmetrically after exercises. Most changes were retained 15 minutes after the exercises. Limitations The retention period was short, and there was no control group of individuals with stroke. Conclusions The results of this efficacy study demonstrated that fast movement exercises improved postural responses to perturbations that were not practiced.
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Wilczyński, Bartosz, Katarzyna Zorena i Daniel Ślęzak. "Dynamic Knee Valgus in Single-Leg Movement Tasks. Potentially Modifiable Factors and Exercise Training Options. A Literature Review". International Journal of Environmental Research and Public Health 17, nr 21 (6.11.2020): 8208. http://dx.doi.org/10.3390/ijerph17218208.
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Dynamic knee valgus (DKV) as an incorrect movement pattern is recognized as a risk factor for lower limb injuries. Therefore, it is important to find the reasons behind this movement to select effective preventive procedures. There is a limited number of publications focusing on specific tasks, separating the double-leg from the single-leg tasks. Test patterns commonly used for DKV assessment, such as single-leg squat (SLS) or single leg landings (SLL), may show different results. The current review presents the modifiable factors of knee valgus in squat and landing single-leg tests in healthy people, as well as exercise training options. The authors used the available literature from PubMed, Scopus, PEDro and clinicaltrials.gov databases, and reviewed physiotherapy journals and books. For the purpose of the review, studies were searched for using 2D or 3D motion analysis methods only in the SLL and SLS tasks among healthy active people. Strengthening and activating gluteal muscles, improving trunk lateral flexion strength, increasing ROM dorsiflexion ankle and midfoot mobility should be taken into account when planning training programs aimed at reducing DKV occurring in SLS. In addition, knee valgus during SLL may occur due to decreased hip abductors, extensors, external rotators strength and higher midfoot mobility. Evidence from several studies supports the addition of biofeedback training exercises to reduce the angles of DKV.
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Turgut, Elif, Gozde Yagci i Volga Bayrakci Tunay. "Hip-Focused Neuromuscular Exercise Provides Immediate Benefits in Foot Pronation and Dynamic Balance: A Sham-Controlled Cross-Over Study". Journal of Sport Rehabilitation 30, nr 7 (1.09.2021): 1088–93. http://dx.doi.org/10.1123/jsr.2020-0549.
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Context: Knowledge on how to utilize a kinetic chain approach in foot and ankle rehabilitation is important. Objective: The aim of this study was to investigate the immediate effects of hip-focused neuromuscular exercise on foot pronation and single-leg neuromuscular control. Design: Cross-over study. Setting: University laboratory. Participants: This cross-over study included 44 asymptomatic volunteers with foot pronation. Interventions: All participants performed (1) a hip-focused neuromuscular exercise and (2) a sham exercise in randomized order. Main Outcome Measures: Foot pronation was assessed by the navicular drop test, and lower-extremity neuromuscular control was assessed by the Modified Star Excursion Balance Test and frontal plane projection angle during single-leg squat before and after the experiments. Results: Navicular drop test scores were significantly lower after the hip-focused neuromuscular exercise than after the sham exercise (mean difference [95% CI] = 2.84 [−1.08 to 6.77], P = .003). Modified Star Excursion Balance Test scores in the anterior (P = .008), posteromedial (P = .04), and posterolateral (P < .001) directions were significantly increased after hip-focused neuromuscular exercise. No statistically significant condition × time interaction was found for the frontal plane projection angle (P > .05). However, a main effect of time (P = .003) indicated that less dynamic knee valgus occurred during single-leg squat after both experiments. Conclusions: Hip-focused neuromuscular exercise produced immediate alterations in foot pronation and dynamic balance. Thus, the hip-focused neuromuscular exercise may be used to control foot posture in foot rehabilitation integrated with a kinetic chain approach and could be an effective prevention and treatment strategy.
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O’Connor, Kristian M., Carl Johnson i Lauren C. Benson. "The Effect of Isolated Hamstrings Fatigue on Landing and Cutting Mechanics". Journal of Applied Biomechanics 31, nr 4 (sierpień 2015): 211–20. http://dx.doi.org/10.1123/jab.2014-0098.
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The function of the hamstrings in protecting the ACL is not fully understood. The purpose of this study was to determine how landing knee mechanics were affected by hamstrings fatigue, analyzed with principal components analysis (PCA). Knee joint mechanics were collected during single-leg stride landings that were followed by lateral and vertical jumps. An isokinetic fatigue protocol was employed to reduce hamstrings strength by 75% at the cessation of the exercise protocol. On the landing test day, participants performed the stride landing maneuvers before and after the fatigue protocol. PCA was performed on the landing knee joint angle, moment, and power waveforms, and MANOVAs were conducted on the retained PCs of each waveform (P < .05). On the strength test day, hamstrings strength recovery was assessed with an identical fatigue protocol followed by strength assessment ~75 s after the cessation of exercise. Pre- and postexercise hamstrings strength on this day was assessed with a dependent t test (P < .05). The hamstrings strength remained significantly reduced by ~8% postexercise (75 s). For stride landings followed by vertical jumps, there were significantly reduced knee flexion angles, extensor moments, and energy absorption. This was indicative of a stiffer landing strategy postfatigue, which has been associated with increased ACL loading.
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Porrati-Paladino, Guillermo, i Rubén Cuesta-Barriuso. "Effectiveness of Plyometric and Eccentric Exercise for Jumping and Stability in Female Soccer Players—A Single-Blind, Randomized Controlled Pilot Study". International Journal of Environmental Research and Public Health 18, nr 1 (3.01.2021): 294. http://dx.doi.org/10.3390/ijerph18010294.
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Hamstring muscle injury is common in female soccer players. Changes affecting eccentric strength, flexibility, and the quadriceps–hamstring contraction cycle are risk factors associated with this type of injury. Methods: Seventeen soccer players were randomized to two groups: experimental (plyometric and eccentric exercises without external loads) and control (eccentric exercises without external loads). Eighteen sessions were scheduled over 6 weeks. The exercise program included three plyometric exercises (single-leg squat and lunge, 180 jump, and broad jump stick landing) and three eccentric exercises (Nordic hamstring exercise, diver, and glider). Dependent variables were jumping height (My Jump 2.0 App) and anterior, posteromedial, and posterolateral lower limb stability (Y-Balance test). Results: Following intervention, improvements were found in anterior and posteromedial stability (p = 0.04) in the experimental group. Posterolateral stability improved in athletes included in the control group (p = 0.02). There were differences in the repeated measures analysis for all variables, with no changes in group interaction (p > 0.05). Conclusions: Eccentric exercises, either combined with plyometric exercises or alone, can improve lower limb stability. No changes in jump height were noted in either group. There were no differences between the two groups in the variables studied. Future studies should analyze the effect of external loads on jumping stability and height in the performance of plyometric exercises.
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Dan, Michael J., Kimberly Kai Lun, Luke Dan, Jimmy Efird, Matthew Pelletier, David Broe i William R. Walsh. "Wearable inertial sensors and pressure MAT detect risk factors associated with ACL graft failure that are not possible with traditional return to sport assessments". BMJ Open Sport & Exercise Medicine 5, nr 1 (lipiec 2019): e000557. http://dx.doi.org/10.1136/bmjsem-2019-000557.
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IntroductionAnterior cruciate ligament reconstruction (ACLR) is associated with poor return to sport and high graft re-rupture rates. This study explored the use of a wearable inertial sensor (ViMove) that incorporates an accelerometer and gyroscope, and MatScan pressure sensing mat (TekScan, South Boston, Massachusetts, USA) to provide objective return-to-sport measures.MethodsThree cohorts’ ACLR patients, non-athletic controls and elite athletes (Australian seven’s rugby Olympic Gold medallist). Patients performed biometric and functional tests (thigh circumference and triple hop) and the ViMove knee module (consisting of single and double leg squats, hops and box drops) for lower limb alignment assessment, concurrently with force plate.ResultsElite athletes had less varus/valgus (VV) movement during ViMove exercises compared with the ACLR cohort, who in turn had less VV malalignment than controls. When analysing side-to-side differences, single leg squats and box drop were asymmetrical in the ACL group, with greater malalignment in the reconstructed leg (p<0.05). Subgroup analysis failed to differentiate who passed or failed current return to sport assessment. TekScan pressure plate detected differences in double leg landing and flight time while hopping not detected with ViMove, suggesting ACL patients compensate by offloading the reconstructed leg to improve coronal alignment during double leg activity.ConclusionThe inertial sensor detected differences in motion for patients following ACLR, which are known to be associated with graft rupture and were not detected with functional return to sport testing. Coupling the device with data from a pressure plate provides a powerful assessment tool detecting alignment differences known to be associate with graft failure only previously detected in formal gait analysis.
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Rostami, Anis, Amir Letafatkar, Alli Gokeler i Mehdi Khaleghi Tazji. "The Effects of Instruction Exercises on Performance and Kinetic Factors Associated With Lower-Extremity Injury in Landing After Volleyball Blocks". Journal of Sport Rehabilitation 29, nr 1 (1.01.2020): 51–64. http://dx.doi.org/10.1123/jsr.2018-0163.
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Context: Female volleyball players are more predisposed to anterior cruciate ligament injury in comparison with their male counterparts. Recent research on anterior cruciate ligament injury prevention strategies has shown the positive results of adopting the external focus (EF) of attention in sports. Objective: To determine the effect of 6-week EF instruction exercises on performance and kinetic factors associated with lower-extremity injury in landing after the volleyball blocks of female athletes. Design: Pretest and posttest control study. Setting: University research laboratory. Participants: Thirty-two female volleyball players (18–24 y old) from the same team randomly divided into experimental (n = 16) and control (n = 16) groups. Intervention: The experimental group performed a 6-week exercise program with EF instructions. The control group continued its regular volleyball team schedule. Main Outcome Measures: To assess function, single-leg triple hop test for distance was used. A force plate was used to evaluate kinetic variables including vertical ground reaction forces, the rate of loading, and dynamic postural stability index. All data were assessed at baseline and after the intervention. Results: There was a significant increase in single-leg triple hop test (P < .05) and in the first and second peak ground reaction force, rate of loadings, dynamic postural stability index (P < .05). Conclusion: According to the results of this study, anterior cruciate ligament injury prevention programs should incorporate EF instruction exercises to enhance the kinetics and to increase athletes’ functional performance.
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Dwyer, Maureen K., Samantha N. Boudreau, Carl G. Mattacola, Timothy L. Uhl i Christian Lattermann. "Comparison of Lower Extremity Kinematics and Hip Muscle Activation During Rehabilitation Tasks Between Sexes". Journal of Athletic Training 45, nr 2 (1.03.2010): 181–90. http://dx.doi.org/10.4085/1062-6050-45.2.181.
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Abstract Context: Closed kinetic chain exercises are an integral part of rehabilitation programs after lower extremity injury. Sex differences in lower extremity kinematics have been reported during landing and cutting; however, less is known about sex differences in movement patterns and activation of the hip musculature during common lower extremity rehabilitation exercises. Objective: To determine whether lower extremity kinematics and muscle activation levels differ between sexes during closed kinetic chain rehabilitation exercises. Design: Cross-sectional with 1 between-subjects factor (sex) and 1 within-subjects factor (exercise). Setting: Research laboratory. Patients or Other Participants: Participants included 21 women (age = 23 ± 5.8 years, height = 167.6 ± 5.1 cm, mass = 63.7 ± 5.9 kg) and 21 men (age = 23 ± 4.0 years, height = 181.4 ± 7.4 cm, mass = 85.6 ± 16.5 kg). Intervention(s): In 1 testing session, participants performed 3 trials each of single-leg squat, lunge, and step-up-and-over exercises. Main Outcome Measure(s): We recorded the peak joint angles (degrees) of knee flexion and valgus and hip flexion, extension, adduction, and external rotation for each exercise. We also recorded the electromyographic activity of the gluteus maximus, rectus femoris, adductor longus, and bilateral gluteus medius muscles for the concentric and eccentric phases of each exercise. Results: Peak knee flexion angles were smaller and peak hip extension angles were larger for women than for men across all tasks. Peak hip flexion angles during the single-leg squat were smaller for women than for men. Mean root-mean-square amplitudes for the gluteus maximus and rectus femoris muscles in both the concentric and eccentric phases of the 3 exercises were greater for women than for men. Conclusions: Sex differences were observed in sagittal-plane movement patterns during the rehabilitation exercises. Because of the sex differences observed in our study, future researchers need to compare the findings for injured participants by sex to garner a better representation of altered kinematic angles and muscle activation levels due to injury.
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Dashti Rostami, Komeil, Aynollah Naderi i Abbey Thomas. "Hip Abductor and Adductor Muscles Activity Patterns During Landing After Anterior Cruciate Ligament Injury". Journal of Sport Rehabilitation 28, nr 8 (1.11.2019): 871–76. http://dx.doi.org/10.1123/jsr.2018-0189.
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Context: Hamstring and quadriceps activity adaptations are well known in individuals with anterior cruciate ligament deficiency (ACLD) and reconstructed (ACLR) to potentially compensate for knee joint instability. However, few studies have explored hip muscles activity patterns after ACL injury. Objective: To examine the activation characteristics of gluteus medius (GMED) and adductor longus in ACLR and ACLD subjects compared with controls. Design: Case–control study. Setting: Athletic training room and university lab. Participants: Twelve healthy and 24 ACL-injured (12 ACLR and 12 ACLD) recreationally active male volunteers. Interventions: Surface electromyography of the GMED and adductor longus were recorded during a single-leg vertical drop landing and normalized to maximum voluntary isometric contractions. Main Outcome Measures: Preparatory and reactive muscle activity and coactivation were analyzed from 100 milliseconds prior to initial contact to 250 milliseconds postcontact. Results: During reactive activity, ACL-injured (ACLR and ACLD) participants demonstrated significantly lower peak GMED activity compared with controls (F = 4.33, P = .02). In addition, ACLR participants exhibited significantly lower reactive GMED:adductor longus coactivation muscle activity compared with controls (F = 4.09, P = .03). Conclusion: Our findings suggest neuromuscular adaptations of the hip musculature are present in people at least 2 years from ACL injury. GMED activation exercises should be considered in designing rehabilitation programs for ACL-injured individuals.
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Collett, Johnny, Helen Dawes, Andy Meaney, Cath Sackley, Karen Barker, Derick Wade, Hooshang Izardi, James Bateman, Joan Duda i Elizabeth Buckingham. "Exercise for multiple sclerosis: a single-blind randomized trial comparing three exercise intensities". Multiple Sclerosis Journal 17, nr 5 (19.01.2011): 594–603. http://dx.doi.org/10.1177/1352458510391836.
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Background: The most effective exercise dose has yet to be established for multiple sclerosis (MS). Objective: The aim of this study was to investigate the effect of different exercise intensities in people with MS. Methods: We completed a randomized comparator study of three cycling exercise intensities, with blinded assessment, was carried out in Oxford. Sixty-one adults with MS who fulfilled inclusion criteria were randomized at entry into the study, using a computer-generated list held by an exercise professional, into either: continuous (at 45% peak power, n = 20), intermittent (30 sec on, 30 sec off at 90% peak power, n = 21) or combined (10 min intermittent at 90% peak power then 10 min continuous at 45% peak power, n = 20) exercise for 20 min twice a week for 12 weeks in a leisure facility. Groups were assessed at: baseline, halfway (6 weeks), end intervention (12 weeks) and follow-up (24 weeks). Primary outcome measure was 2 min walk. Results: Fifty-five participants were included in the analysis ( n = continuous 20, intermittent 18, combined 17). No differences were found between groups. After 6 weeks, considering all participants, 2 min walk distance increased by 6.96 ± 2.56 m (95% CI: 1.81 to 12.10, effect size (es): 0.25, p < 0.01). The continuous group increased by 4.71 ± 4.24 m (95% CI: −3.80 to 13.22, es : 0.06), intermittent by 12.94 ± 4.71 m (95% CI: 3.97 to 21.92, es: 0.28) and combined by 3.22 ± 4.60 m (95% CI: −6.01 to 12.46, es: 0.04) . Two minute walk did not significantly change between further assessments. Between 6 and 12 weeks there was a drop in attendance that seemed to be associated with the intermittent and combined groups; these groups also had a greater number of adverse events (leg pain during cycling most common) and dropouts ( n = continuous 1, intermittent 5, combined 10). Considering all participants, 6 weeks of cycling exercise produced benefits in mobility that were maintained with further sessions. Conclusion: While no differences were found between groups, greater benefit may be associated with higher-intensity exercise, but this may be less well tolerated.CONSORT - trial registration number (ISRCTN89009719)
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Karagianni, Konstantina, Olyvia Donti, Christos Katsikas i Gregory C. Bogdanis. "Effects of Supplementary Strength–Power Training on Neuromuscular Performance in Young Female Athletes". Sports 8, nr 8 (24.07.2020): 104. http://dx.doi.org/10.3390/sports8080104.
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This study examined the effects of a short-duration supplementary strength–power training program on neuromuscular performance and sport-specific skills in adolescent athletes. Twenty-three female “Gymnastics for All” athletes, aged 13 ± 2 years, were divided into a training group (TG, n = 12) and a control group (CG, n = 11). Both groups underwent a test battery before and after 10 weeks of intervention. TG completed, in addition to gymnastics training, a supplementary 7–9 min program that included two rounds of strength and power exercises for arms, torso, and legs, executed in a circuit fashion with 1 min rest between rounds, three times per week. Initially, six exercises were performed (15 s work–15 s rest), while the number of exercises was decreased to four and the duration of each exercise was increased to 30 s (30 s rest) after the fifth week. TG improved countermovement jump performance with one leg (11.5% ± 10.4%, p = 0.002) and two legs (8.2% ± 8.8%, p = 0.004), drop jump performance (14.4% ± 12.6%, p = 0.038), single-leg jumping agility (13.6% ± 5.2%, p = 0.001), and sport-specific performance (8.8% ± 7.4%, p = 0.004), but not 10 m sprint performance (2.4% ± 6.6%, p = 0.709). No change was observed in the CG (p = 0.41 to 0.97). The results of this study indicated that this supplementary strength–power program performed for 7–9 min improves neuromuscular and sport-specific performance after 10 weeks of training.
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Watanabe, Saya, Junya Aizawa, Manabu Shimoda, Mitsuhiro Enomoto, Tomomasa Nakamura, Atushi Okawa i Kazuyoshi Yagishita. "Effect of short-term fatigue, induced by high-intensity exercise, on the profile of the ground reaction force during single-leg anterior drop-jumps". Journal of Physical Therapy Science 28, nr 12 (2016): 3371–75. http://dx.doi.org/10.1589/jpts.28.3371.
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Stöggl, Thomas, i Dennis-Peter Born. "Near Infrared Spectroscopy for Muscle Specific Analysis of Intensity and Fatigue during Cross-Country Skiing Competition—A Case Report". Sensors 21, nr 7 (4.04.2021): 2535. http://dx.doi.org/10.3390/s21072535.
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The aims of the study were to assess the robustness and non-reactiveness of wearable near-infrared spectroscopy (NIRS) technology to monitor exercise intensity during a real race scenario, and to compare oxygenation between muscle groups important for cross-country skiing (XCS). In a single-case study, one former elite XCS (age: 39 years, peak oxygen uptake: 65.6 mL/kg/min) was equipped with four NIRS devices, a high-precision global navigation satellite system (GNSS), and a heart rate (HR) monitor during the Vasaloppet long-distance XCS race. All data were normalized to peak values measured during incremental laboratory roller skiing tests two weeks before the race. HR reflected changes in terrain and intensity, but showed a constant decrease of 0.098 beats per minute from start to finish. Triceps brachii (TRI) muscle oxygen saturation (SmO2) showed an interchangeable pattern with HR and seems to be less affected by drift across the competition (0.027% drop per minute). Additionally, TRI and vastus lateralis (VL) SmO2 revealed specific loading and unloading pattern of XCS in uphill and downhill sections, while rectus abdominus (RA) SmO2 (0.111% drop per minute) reflected fatigue patterns occurring during the race. In conclusion, the present preliminary study shows that NIRS provides a robust and non-reactive method to monitor exercise intensity and fatigue mechanisms when applied in an outdoor real race scenario. As local exercise intensity differed between muscle groups and central exercise intensity (i.e., HR) during whole-body endurance exercise such as XCS, NIRS data measured at various major muscle groups may be used for a more detailed analysis of kinetics of muscle activation and compare involvement of upper body and leg muscles. As TRI SmO2 seemed to be unaffected by central fatigue mechanisms, it may provide an alternative method to HR and GNSS data to monitor exercise intensity.
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Karagianni, Konstantina, Olyvia Donti i Gregory C. Bogdanis. "Effects of a Supplementary Strength-Power Training Program on Neuromuscular Performance in Young Female Athletes". Proceedings 25, nr 1 (30.08.2019): 7. http://dx.doi.org/10.3390/proceedings2019025007.
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AIM: This study examined the effects of a high-intensity, short-duration supplementary strength-power training program on neuromuscular performance and sport-specific skills of young female “Gymnastics for All” athletes. MATERIAL & METHOD: Twenty-four female “Gymnastics for all” athletes aged 13 ± 2 years, with at least two years of competitive-level training experience, took part in this study. Participants were divided into training (TG, n = 13) and control groups (CG, n = 11), who completed the same 3-day per week gymnastics training program over 10 weeks, with the TG completing a supplementary 7–9 min long strength-power program at the end of each training session. This training program consisted of two rounds of strength and power exercises for arms and legs, executed in a circuit fashion with 1-min rest between rounds. The exercises used included plyometrics for upper and lower body using body weight resistance, as well as strength-power exercises using elastic bands and light kettle bells. Participants performed each exercise at maximum voluntary effort, as fast and as hard as possible. Initially, six different exercises were performed per round (15 s work and 15 s rest), while the number of exercises per round was gradually decreased to four and the duration of each exercise was increased to 30 s (with 30 s rest). Data were analyzed using mixed-model 2-way ANOVA (group × time). RESULTS: After 10 weeks of training the TG improved countermovement jump performance with one leg (by 11.9 ± 2.8%, p = 0.001) and two legs (by 7.1 ± 2.7%, p = 0.026), drop jump performance (by 11.9 ± 2.8%, p = 0.002), single-leg jumping agility (by 12.9 ± 1.5%, p = 0.001), sport-specific performance, i.e., repeated rondats (by 8.2 ± 2.1%, p = 0.004), but not 10-m sprint performance (2.5 ± 1.7%, p = 0.23). There was no change in these neuromuscular performance parameters in the CG (p = 0.13 to 0.94). CONCLUSIONS: The results of this study show that this supplementary strength-power program performed for only 7–9 min at the end of each session improved neuromuscular and sport-specific performance after 10 weeks of training.
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Chinnasee, Chamnan, Gillian Weir, Siriporn Sasimontonkul, Jacqueline Alderson i Cyril Donnelly. "A Biomechanical Comparison of Single-Leg Landing and Unplanned Sidestepping". International Journal of Sports Medicine 39, nr 08 (14.06.2018): 636–45. http://dx.doi.org/10.1055/a-0592-7422.
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AbstractUnplanned sidestepping and single-leg landing have both been used to screen athletes for injury risk in sport. The aim of this study was to directly compare the lower limb mechanics of three single-leg landing tasks and an unplanned sidestepping task. Thirteen elite female team sport athletes completed a series of non-contact single-leg drop landings, single-leg countermovement jumps, single-leg jump landings and unplanned sidestepping in a randomized counterbalanced design. Three dimensional kinematics (250 Hz) and ground reaction force (2,000 Hz) data with a participant specific lower limb skeletal model were used to calculate and compare hip, knee and ankle joint kinematics, peak joint moments, instantaneous joint power and joint work during the weight acceptance phase of each sporting task (α=0.05). Peak knee joint moments and relevant injury risk thresholds were used to classify each athlete's anterior cruciate ligament injury risk during unplanned sidestepping and single-leg jump landing. Results showed that peak joint moments, power and work were greater during the single-leg jump landing task when compared to the single-leg drop landings and single-leg countermovement jumps tasks. Peak frontal and sagittal plane knee joint moments, knee joint power, as well as hip and knee joint work were greater during unplanned sidestepping when compared to the landing tasks. Peak ankle joint moments, power and work were greater during the landing tasks when compared to unplanned sidestepping. For 4 of the 13 athletes tested, their anterior cruciate ligament injury risk classification changed depending on whether they performed an unplanned sidestepping or single-leg jump landing testing procedure. To summarize, a single-leg jump landing testing procedure places a larger mechanical on the ankle joint when compared to single-leg drop landings, single-leg countermovement jumps and unplanned sidestepping. An unplanned sidestepping testing procedure places a larger mechanical demand on the knee joint when compared to single-leg landing tasks. Both unplanned sidestepping and single-leg jump landing testing procedures are recommended for classifying an athlete's anterior cruciate ligament injury risk in sport.
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Harris-Hayes, Marcie, Karen Steger-May, Allyn M. Bove, Stefanie N. Foster, Michael J. Mueller, John C. Clohisy i G. Kelley Fitzgerald. "Movement pattern training compared with standard strengthening and flexibility among patients with hip-related groin pain: results of a pilot multicentre randomised clinical trial". BMJ Open Sport & Exercise Medicine 6, nr 1 (marzec 2020): e000707. http://dx.doi.org/10.1136/bmjsem-2019-000707.
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Study designPilot, multicentre randomised clinical trial (RCT).ObjectivesAssess viability of performing a definitive RCT and compare preliminary effects of movement pattern training (MoveTrain) and strengthening/flexibility (Standard) to improve function in people with chronic hip-related groin pain (HRGP).BackgroundTo determine the best physical therapist-led intervention for patients with HRGP, we must understand treatment effects of different treatment modes.MethodsForty-six patients (17M:29F; 29±5.3 years; body mass index 25.6±6.3 kg/m2) with HRGP were randomised. MoveTrain included task-specific training to optimise biomechanics during daily tasks. Standard included strengthening/flexibility. Treatment included 10 visits/12 weeks and home exercise programme (HEP). Primary outcomes for feasibility were recruitment, retention, treatment adherence and treatment fidelity. Secondary outcomes were patient-reported function (Hip disability and Osteoarthritis Outcome Score (HOOS)), lower extremity kinematics and hip muscle strength.ResultsWe achieved target recruitment, and retention was excellent (91%). Patient session attendance was high (93%); however, reported HEP adherence (62%) was lower than expected. Physical therapists’ adherence to treatment protocols was high (90%). Patients demonstrated high treatment receipt; 91% of exercises performed were rated independent. Both groups demonstrated clinically important improvements in function (HOOS) and muscle strength; however, there were no between-group differences (HOOS subscales, p≥0.13, strength, p≥0.34). Compared with Standard, MoveTrain demonstrated greater reductions in hip adduction (p=0.016) and pelvic drop (p=0.026) during a single leg squat. No adverse events were noted.ConclusionOur experience in completing this RCT confirmed that a larger, multicentre RCT is feasible and highlighted modifications we will implement to optimise the future RCT.Trial registration numberNCT02913222.
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Nordin, Andrew D., i Janet S. Dufek. "Load Accommodation Strategies and Movement Variability in Single-Leg Landing". Journal of Applied Biomechanics 33, nr 4 (sierpień 2017): 241–47. http://dx.doi.org/10.1123/jab.2016-0097.
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Our purpose was to examine changes in participant-specific single-leg landing strategies and intra-individual movement variability following alterations in mechanical task demands via external load and landing height. Nineteen healthy volunteers (15M, 4 F, age: 24.3 ± 4.9 y, mass: 78.5 ± 14.7 kg, height: 1.73 ± 0.08 m) were analyzed among 9 single-leg drop landing trials in each of 6 experimental conditions (3 load and 2 landing height) computed as percentages of participant bodyweight (BW, BW + 12.5%, BW + 25%) and height (H12.5% & H25%). Lower-extremity sagittal joint angles and moments (hip, knee, and ankle), vertical ground reaction forces (GRFz), and electrical muscle activities (gluteus maximus, biceps femoris, vastus medialis, medial gastrocnemius, and tibialis anterior muscles) were analyzed. Individual single-leg drop landing strategies were identified using landing impulse predictions and the Load Accommodation Strategies Model (James et al., 2014). Intra-individual movement variability was assessed from neuromechanical synergies extracted using single-case principal component analyses (PCA). Fewer contrasting single-leg landing strategies were identified among participants under greater mechanical task demands (p < .001) alongside lesser intra-individual movement variability (p < .001). These results reveal changes in movement control under greater mechanical task demands, which may have implications for understanding overuse injury mechanisms in landing.
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Kipp, Kristof, Ron Pfeiffer, Michelle Sabick, Chad Harris, Jeanie Sutter, Seth Kuhlman i Kevin Shea. "Muscle Synergies During a Single-Leg Drop-Landing in Boys and Girls". Journal of Applied Biomechanics 30, nr 2 (kwiecień 2014): 262–68. http://dx.doi.org/10.1123/jab.2012-0193.
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The purpose of this study was to investigate muscle activation patterns during a landing task in boys and girls through the use of muscle synergies. Electromyographical data from six lower extremity muscles were collected from 11 boys and 16 girls while they performed single-leg drop-landings. Electromyographical data from six leg muscles were rectified, smoothed, and normalized to maximum dynamic muscle activity during landing. Data from 100 ms before to 100 ms after touchdown were submitted to factor analyses to extract muscle synergies along with the associated activation and weighing coefficients. Boys and girls both used three muscle synergies. The activation coefficients of these synergies captured muscle activity during the prelanding, touchdown, and postlanding phases of the single-leg drop-landing. Analysis of the weighing coefficients indicated that within the extracted muscle synergies the girls emphasized activation of the medial hamstring muscle during the prelanding and touchdown synergy whereas boys emphasized activation of the vastus medialis during the postlanding synergy. Although boys and girls use similar muscle synergies during single-leg drop-landings, they differed in which muscles were emphasized within these synergies. The observed differences in aspects related to the muscle synergies during landing may have implications with respect to knee injury risk.
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Kim, Jinah, Sung Cheol Lee, Youngmin Chun, Hyung-Pil Jun, Jeffrey G. Seegmiller, Kyung Min Kim i Sae Yong Lee. "Effects of a 4-Week Short-Foot Exercise Program on Gait Characteristics in Patients With Stage II Posterior Tibial Tendon Dysfunction". Journal of Sport Rehabilitation 30, nr 1 (1.01.2021): 120–28. http://dx.doi.org/10.1123/jsr.2019-0211.
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Context: Clinically, it has been suggested that increased activation of intrinsic foot muscles may alter the demand of extrinsic muscle activity surrounding the ankle joint in patients with stage II posterior tibial tendon dysfunction. However, there is limited empirical evidence supporting this notion. Objective: The purpose of this study was to investigate the effects of a 4-week short-foot exercise (SFE) on biomechanical factors in patients with stage II posterior tibial tendon dysfunction. Design: Single-group pretest–posttest. Setting: University laboratory. Participants: Fifteen subjects (8 males and 7 females) with stage II posterior tibial tendon dysfunction who had pain in posterior tibial tendon, pronated foot deformity (foot posture index ≥+6), and flexible foot deformity (navicular drop ≥10 mm) were voluntarily recruited. Intervention: All subjects completed a 4-week SFE program (15 repetitions × 5 sets/d and 3 d/wk) of 4 stages (standing with feedback, sitting, double-leg, and one-leg standing position). Main Outcome Measures: Ankle joint kinematics and kinetics and tibialis anterior and fibularis longus muscle activation (% maximum voluntary isometric contraction) during gait were measured before and after SFE program. Cohen d effect size (ES [95% confidence intervals]) was calculated. Results: During the first rocker, tibialis anterior activation decreased at peak plantarflexion (ES = 0.75 [0.01 to 1.49]) and inversion (ES = 0.77 [0.03 to 1.51]) angle. During the second rocker, peak dorsiflexion angle (ES = 0.77 [0.03 to 1.51]) and tibialis anterior activation at peak eversion (ES = 1.57 [0.76 to 2.39]) reduced. During the third rocker, the peak abduction angle (ES = 0.80 [0.06 to 1.54]) and tibialis anterior and fibularis longus activation at peak plantarflexion (ES = 1.34 [0.54 to 2.13]; ES = 1.99 [1.11 to 2.86]) and abduction (ES = 1.29 [0.50 to 2.08]; ES = 1.67 [0.84 to 2.50]) decreased. Conclusions: Our 4-week SFE program may have positive effects on changing muscle activation patterns for tibialis anterior and fibularis longus muscles, although it could not influence their structural deformity and ankle joint moment. It could produce a potential benefit of decreased tibialis posterior activation.
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Lee, Hyojeong, Kyunghi Hong i Yejin Lee. "Compression pants with differential pressurization: Kinetic and kinematical effects on stability". Textile Research Journal 87, nr 13 (5.07.2016): 1554–64. http://dx.doi.org/10.1177/0040517516657056.
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Clothing pressure is a very important variable in compression garments that is frequently omitted in other studies, despite the possibility of altering the experimental design and results. Most studies focus on testing the effects of released products rather than on how to design them. The aim of this study is to identify methods to increase stability of an extremity by developing compression pants with a design that assigns differential pressurization. CP1 (clothing pressure knee region: 0.95–1.03 kPa), which reinforces the knee joint, and CP2 (clothing pressure knee region: 1.67–2.12 kPa), which reinforces the knee joint and hamstring, are developed. In addition, CCP (clothing pressure knee region: 0.44–0.58 kPa) was developed as a control garment. Seven subjects wearing CP1, CP2, or CCP, performed single-leg landing from 40 cm height, for motion analysis. As a result, the angular velocity of the hip and knee, as well as the knee joint range of motion was increased significantly when CP1 are worn. Therefore, CP1 is efficient in absorbing the energy of the impact, making it much practical in terms of stability. The peak vertical ground reaction force showed little difference when different design of compression pants were tested. Meanwhile, CP2 significantly increases the knee moment. It is important to add that even a subtle manipulation of the level, location, or the method of pressurization significantly changes the stability of joints and the performance of exercise. This research shows that the functions of compression garments differ according to the level of pressurization and differential pressurization.
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Durall, Christopher J., Thomas W. Kernozek, Melissa Kersten, Maria Nitz, Jonathan Setz i Sara Beck. "Associations Between Single-Leg Postural Control and Drop-Landing Mechanics in Healthy Women". Journal of Sport Rehabilitation 20, nr 4 (listopad 2011): 406–18. http://dx.doi.org/10.1123/jsr.20.4.406.
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Context:Impaired postural control in single-limb stance and aberrant drop-landing mechanics have been implicated separately as risk factors for noncontact anterior cruciate ligament (ACL) injury, but associations between these variables has not been reported.Objective:To determine whether there are associations between single-limb postural control and drop-landing mechanics.Setting:University motion-analysis laboratory.Design:Single-leg-landing kinematic and kinetic data were collected after participants dropped from a hang bar. Postural-control variables COP excursion and velocity were assessed during single-leg barefoot standing on a force platform.Participants:A convenience sample of 24 healthy women.Main Outcome Measures:Pearson product–moment correlation coefficients.Results:Strong associations were measured between maximal knee-abduction moment and COP excursion (r = .529, P = .003) and average COP velocity (r = .529, P = .003). Strong inverse associations were measured between minimum hip-flexion angle and COP excursion (r = −.521, P = .003) and average COP velocity (r = −.519, P = .003).Conclusions:Participants with decreased postural control had higher knee-abduction moments and a more extended hip on landing, which have been implicated separately as risk factors for ACL injury. A longitudinal prospective analysis is needed to determine whether force-platform postural-control measures can identify athletes at risk for ACL injury.
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Mueske, Nicole, Mia J. Katzel, Kyle P. Chadwick, Curtis VandenBerg, J. Lee Pace, Tracy Zaslow, Bianca Edison, Bridget G. O’Callahan, Haley L. K. Nakata i Tishya Wren. "BIOMECHANICAL SYMMETRY DURING DROP JUMP AND SINGLE-LEG HOP LANDING IN UNINJURED ADOLESCENT ATHLETES". Orthopaedic Journal of Sports Medicine 7, nr 3_suppl (1.03.2019): 2325967119S0002. http://dx.doi.org/10.1177/2325967119s00023.
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BACKGROUND Symmetry of strength, thigh girth and hop distance is often used as a benchmark in return to sport testing. Using symmetry as a gold standard has been translated into biomechanical testing; however, kinematic and kinetic symmetry during dynamic tasks in adolescents without lower extremity injury is not well understood. The purpose of this study was to assess symmetry in uninjured adolescent athletes during double and single-leg landing tasks. METHODS 36 uninjured athletes (ages 7-15 years, mean 12.4, SD 2.4; 47% female) completed vertical drop jump (DJ) and single-leg hop (SLH) for distance tasks; lower extremity kinematics and kinetics were collected through 3-D motion analysis using a 6 degree-of-freedom model; 2-3 trials per participant per side were analyzed. Differences between dominant and non-dominant limbs from initial contact to peak knee flexion were examined using statistical parametric mapping (SPM), a methodology for performing statistics on time series data. The SPM method allows differences between dominant and non-dominant limbs to be evaluated for statistical significance at all time points throughout the landing movement. RESULTS During both DJ (Figure 1) and SLH (Figure 2), the dominant limb tended to be more internally rotated at the hip throughout landing, but the asymmetry was significant only for short periods early in landing during the DJ (p<0.05) and at mid-landing in the SLH (p=0.01). Additionally, the dominant hip tended to have less abducted positioning throughout both tasks, but differed significantly only shortly after initial contact in the SLH landing (p=0.04). The dominant limb ankle was less inverted (p<0.001) with a lower external inversion moment (p<0.001) during early to mid-landing in the DJ, and less everted (p=0.04) with higher external inversion moment (p=0.05) early in SLH landing. The only asymmetry observed in either task in the sagittal plane was slightly higher external ankle flexion moments (p=0.05) just after initial contact in the DJ. No asymmetries were detected in peak vertical ground reaction force or knee kinematics/kinetics for either task. CONCLUSION/SIGNIFICANCE Uninjured adolescent athletes exhibited only slight asymmetries during double and single-leg landing, primarily at the hip and ankle in the frontal and transverse planes. The hip may perform larger adjustments to accommodate center of mass location, while the ankle fine-tunes the landing as the closest segment to the ground. This study supports that normal biomechanics are symmetric during double and single-leg landing. Biomechanical symmetry is therefore a reasonable target in return to sport assessment. While only small regions of statistically significant asymmetry were identified, it is possible that greater asymmetries are present within individuals. In the grouped analysis, asymmetry towards the dominant side for one individual could offset asymmetry towards the non-dominant side of another individual. In future analysis, we will examine the magnitude and significance of within-subject asymmetry.
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Marshall, Brendan M., Andrew D. Franklyn-Miller, Kieran A. Moran, Enda A. King, Siobhán C. Strike i Éanna C. Falvey. "Can a Single-Leg Squat Provide Insight into Movement Control and Loading During Dynamic Sporting Actions in Patients With Athletic Groin Pain?" Journal of Sport Rehabilitation 25, nr 2 (maj 2016): 117–25. http://dx.doi.org/10.1123/jsr.2014-0274.
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Context:Chronic athletic groin pain (AGP) is common in field sports and has been associated with abnormal movement control and loading of the hip and pelvis during play. A single-leg squat (SLS) is commonly used by clinicians to assess movement control, but whether it can provide insight into control during more dynamic sporting movements in AGP patients is unclear.Objective:To determine the relationships between biomechanical measures in an SLS and the same measures in a single-leg drop landing, single-leg hurdle hop, and a cutting maneuver in AGP patients.Design:Cross-sectional study.Setting:Biomechanics laboratory.Patients:40 recreational field-sports players diagnosed with AGP.Intervention:A biomechanical analysis of each individual’s SLS, drop landing, hurdle hop, and cut was undertaken.Main Outcome Measures:Hip, knee, and pelvis angular displacement and hip and knee peak moments. Pearson product–moment correlations were used to examine relationships between SLS measures and equivalent measures in the other movements.Results:There were no significant correlations between any hip or pelvis measure in the SLS with the same measures in the drop landing, hurdle hop, or cut (r = .03–.43, P > .05). Knee frontal- and transverse-plane angular displacement were related in the SLS and drop landing only, while knee moments were related in the SLS, drop-landing, and hurdle hop (r = .50–.67, P < .05).Conclusion:For AGP patients, an SLS did not provide meaningful insight into hip and pelvis control or loading during sporting movements that are associated with injury development. The usefulness of an SLS test in the assessment of movement control and loading in AGP patients is thus limited. The SLS provided moderate insight into knee control while landing and therefore may be of use in the examination of knee-injury risk.
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Kuenze, Christopher, Thomas Birchmeier, Jeffrey Kovan i Caroline Lisee. "Physical and Psychological Predictors of Single-leg Drop Landing Biomechanics ACL Reconstruction." Medicine & Science in Sports & Exercise 51, Supplement (czerwiec 2019): 612. http://dx.doi.org/10.1249/01.mss.0000562330.77983.69.
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Doherty, C., C. Bleakley, J. Hertel, B. Caulfield, J. Ryan i E. Delahunt. "Single-leg drop landing motor control strategies following acute ankle sprain injury". Scandinavian Journal of Medicine & Science in Sports 25, nr 4 (27.06.2014): 525–33. http://dx.doi.org/10.1111/sms.12282.
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Brazen, Danielle M., M. Kent Todd, Jatin P. Ambegaonkar, Roshna Wunderlich i Connie Peterson. "The Effect of Fatigue on Landing Biomechanics in Single-Leg Drop Landings". Clinical Journal of Sport Medicine 20, nr 4 (lipiec 2010): 286–92. http://dx.doi.org/10.1097/jsm.0b013e3181e8f7dc.
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Tamura, Akihiro, Kiyokazu Akasaka, Takahiro Otsudo, Yutaka Sawada, Yu Okubo, Jyunya Shiozawa, Yuka Toda i Kaori Yamada. "Fatigue Alters Landing Shock Attenuation During a Single-Leg Vertical Drop Jump". Orthopaedic Journal of Sports Medicine 4, nr 1 (11.01.2016): 232596711562641. http://dx.doi.org/10.1177/2325967115626412.
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Sanomura, M., i K. Irie. "Relationship between leg and foot alignment and dynamic knee valgus during single-leg squat, single-leg drop landing and cutting tasks". British Journal of Sports Medicine 45, nr 4 (27.03.2011): 371. http://dx.doi.org/10.1136/bjsm.2011.084038.172.
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Romanchuk, Nicholas J., Michael J. Del Bel i Daniel L. Benoit. "SEX-SPECIFIC ENERGY ABSORPTION STRATEGIES DURING UNANTICIPATED SINGLE-LEG LANDINGS IN ADOLESCENTS: IMPLICATIONS FOR KNEE INJURIES". Orthopaedic Journal of Sports Medicine 8, nr 4_suppl3 (1.04.2020): 2325967120S0023. http://dx.doi.org/10.1177/2325967120s00237.
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Background: The vast majority of ACL injuries in adolescents occur during non-contact injuries, in particular single-leg landings. The magnitude of energy absorption about each joint during theses landings influences the internal and external forces acting on the joints of the lower extremity. Understanding the biomechanics of landing in adolescent male and female athletes may provide insight into these non-contact injury mechanisms. Hypothesis/Purpose: This study set out to identify sex-specific energy absorption strategies during single-leg landing and determine the relationship between joint strength and the observed strategies. To better represent real-world conditions, we developed a novel unanticipated drop-jump landing protocol for this population. Methods: Thirty-one healthy youth athletes completed unanticipated single-leg drop-jump landings on their dominant limb. Kinematics and lower-limb contributions to energy absorption were calculated over the landing phase for each jump. Independent t-tests as well as Mann-Whitney U tests determined the presence of statistical differences between sexes. Pearson and Spearman correlation coefficients determined the relationship between isometric joint strength and the observed kinematics and energy absorption. Results: Females participants absorbed a larger proportion of the landing forces at the ankle and smaller proportion at the hip compared to males. Females also reached larger peak negative joint power in their knee and ankle. Both hip extension and ankle plantar flexion strength were correlated with greater spine flexion and less pelvic flexion. Conclusion: Females adopted an energy absorption strategy which utilized distal joints to absorb a larger portion of the landing forces and tended to absorb the forces later relative to males. A greater reliance on the distal joints is related to reduced hip strength and may increase the risk for sustaining an ACL injury.
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KINOSHITA, Megumi, Yukio URABE, Noriaki MAEDA, Eri FUJII, Junpei SASADAI, Sho IWATA, Dairoku KAWAHARA i Shuhei NUMANO. "Relationship between Foot and Knee Valgus Movement in the Single-leg Drop-landing". Rigakuryoho kagaku 31, nr 2 (2016): 227–31. http://dx.doi.org/10.1589/rika.31.227.
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DiCesare, Christopher A., Scott Bonnette, Gregory D. Myer i Adam W. Kiefer. "Differentiating Successful and Unsuccessful Single-Leg Drop Landing Performance Using Uncontrolled Manifold Analysis". Motor Control 24, nr 1 (1.01.2020): 75–90. http://dx.doi.org/10.1123/mc.2017-0076.
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Biomechanical analysis can effectively identify factors associated with task performance and injury risk, but often does not account for the interaction among the components that underlie task execution. Uncontrolled manifold (UCM) analyses were applied to data from 38 female, adolescent athletes performing single-leg drop landings and were used to differentiate successful and unsuccessful task performance by examining the frontal plane joint variance within the UCM (VUCM) that stabilized the horizontal center of mass position (VUCM) and within the orthogonal subspace (VORT). The UCM revealed stronger coordination, indicated by the VUCM/VORT ratio, in the successful condition. This may inform future research examining reduced motor coordination in failed movement tasks and its relation to injury risk and allow for targeted interventions that consider coordination processes rather than joint-specific outcomes.
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Sakurai, Aiko, Kengo Harato, Yutaro Morishige, Shu Kobayashi, Yasuo Niki i Takeo Nagura. "Effects of Toe Direction on Biomechanics of Trunk, Pelvis, and Lower-Extremity During Single-Leg Drop Landing". Journal of Sport Rehabilitation 29, nr 8 (1.11.2020): 1069–74. http://dx.doi.org/10.1123/jsr.2019-0050.
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Context: Toe direction is an important factor affecting knee biomechanics during various movements. However, it is still unknown whether toe direction will affect trunk and pelvic movements. Objective: To examine and clarify the effects of toe directions on biomechanics of trunk and pelvis as well as lower-extremities during single-leg drop landing (SLDL). Design: Descriptive laboratory study. Setting: Research laboratory. Participants: A total of 27 male recreational-level athletes. Intervention(s): Subjects performed SLDL under 3 different toe directions, including 0° (toe neutral), 20° (toe-in [TI]), and −20° (toe-out). SLDL was captured using a motion analysis system. Nondominant leg (27 left) was chosen for the analysis. Main Outcome Measures: Peak values of kinematic and kinetic parameters during landing phase were assessed. In addition, those parameters at the timing of peak vertical ground reaction force were also assessed. The data were statistically compared among 3 different toe directions using 1-way repeated measures of analysis of variance or Friedman χ2 r test. Results: Peak knee abduction angle and moment in TI were significantly larger than in toe neutral and toe-out (P < .001). Moreover, peak greater anterior inclination, greater inclination, and rotation of trunk and pelvis toward the nonlanding side were seen in TI (P < .001). At the timing of peak vertical ground reaction force, trunk inclined to the landing side with larger knee abduction angle in TI (P < .001). Conclusions: Several previous studies suggested that larger knee abduction angle and moment on landing side as well as trunk and pelvic inclinations during landing tasks were correlated with knee ligament injury. However, it is still unknown concerning the relationship between toe direction and trunk/pelvis movements during landing tasks. From the present study, TI during SLDL would strongly affect biomechanics of trunk and pelvis as well as knee joint, compared with toe neutral and toe-out.
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Morikawa, Masanori, Noriaki Maeda, Makoto Komiya, Arisu Hirota, Rami Mizuta, Toshiki Kobayashi, Kazuki Kaneda, Yuichi Nishikawa i Yukio Urabe. "Contribution of Plantar Fascia and Intrinsic Foot Muscles in a Single-Leg Drop Landing and Repetitive Rebound Jumps: An Ultrasound-Based Study". International Journal of Environmental Research and Public Health 18, nr 9 (23.04.2021): 4511. http://dx.doi.org/10.3390/ijerph18094511.
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The plantar fascia and intrinsic foot muscles (IFM) modulate foot stiffness. However, it is unclear whether the corresponding ultrasonography findings reflect it. This study aimed to examine the effect of the plantar fascia and IFM morphologies on force attenuation during landing and reactivity when jumping in healthy adults (n = 21; age, 21–27 years). Thickness, cross-sectional area (CSA), and hardness of the plantar fascia, abductor hallucis (AbH), and flexor hallucis brevis (FHB) muscles were measured using ultrasonography. Single-leg drop landing and repetitive rebound jumping tests assessed the ground reaction force (GRF) and reactive jump index (RJI), respectively. The CSA of FHB was negatively correlated with maximum vertical GRF (r = −0.472, p = 0.031) in the single-leg drop landing test. The CSA of AbH was negatively correlated with contact time (r = −0.478, p = 0.028), and the plantar fascia thickness was positively correlated with jump height (r = 0.615, p = 0.003) and RJI (r = 0.645, p = 0.002) in the repetitive bound jump test. In multivariate regression analysis, only the plantar fascia thickness was associated with RJI (β = 0.152, 95% confidence interval: 7.219–38.743, p = 0.007). The CSA of FHB may contribute to force attenuation during landing. The thickness of the plantar fascia and CSA of AbH may facilitate jumping high with minimal contact time.
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KOSHINO, Yuta, Masanori YAMANAKA i Naoki TAKEDA. "The Relationships between Pre-landing Muscle Activation and Ankle Position at Ground Contact during Single-Leg Drop Landing". Rigakuryoho Kagaku 28, nr 4 (2013): 527–32. http://dx.doi.org/10.1589/rika.28.527.
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Niu, Wenxin, Tienan Feng, Chenghua Jiang i Ming Zhang. "Peak Vertical Ground Reaction Force during Two-Leg Landing: A Systematic Review and Mathematical Modeling". BioMed Research International 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/126860.
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Objectives. (1) To systematically review peak vertical ground reaction force (PvGRF) during two-leg drop landing from specific drop height (DH), (2) to construct a mathematical model describing correlations between PvGRF and DH, and (3) to analyze the effects of some factors on the pooled PvGRF regardless of DH.Methods. A computerized bibliographical search was conducted to extract PvGRF data on a single foot when participants landed with both feet from various DHs. An innovative mathematical model was constructed to analyze effects of gender, landing type, shoes, ankle stabilizers, surface stiffness and sample frequency on PvGRF based on the pooled data.Results. Pooled PvGRF and DH data of 26 articles showed that the square root function fits their relationship well. An experimental validation was also done on the regression equation for the medicum frequency. The PvGRF was not significantly affected by surface stiffness, but was significantly higher in men than women, the platform than suspended landing, the barefoot than shod condition, and ankle stabilizer than control condition, and higher than lower frequencies.Conclusions. The PvGRF and root DH showed a linear relationship. The mathematical modeling method with systematic review is helpful to analyze the influence factors during landing movement without considering DH.
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Lin, Cheng-Chieh, Shing-Jye Chen, Wan-Chin Lee i Cheng-Feng Lin. "Effects of Different Ankle Supports on the Single-Leg Lateral Drop Landing Following Muscle Fatigue in Athletes with Functional Ankle Instability". International Journal of Environmental Research and Public Health 17, nr 10 (14.05.2020): 3438. http://dx.doi.org/10.3390/ijerph17103438.
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Background: Ankle support has been utilized for athletes with functional ankle instability (FAI), however, its effect on the landing performance during muscle fatigue is not well understood. This study aimed to examine the effects of ankle supports (ankle brace vs. Kinesio tape) on athletes with FAI following fatigued single-leg landing. Methods: Thirty-three young FAI athletes (CAIT scores < 24) were randomly allocated to control (Cn), ankle brace (AB) and Kinesio tape (KT) groups. All athletes performed single-leg lateral drop landings following ankle fatigue protocol. The fatigue-induced changes in kinetic parameters were measured among three groups. Results: A significant increase in peak vertical ground reaction force (vGRF) was found in the AB group (0.12% body weight (BW)) compared to that of the KT (0.02% BW) and Cn (median = 0.01% BW) groups. Significant decrease in both COP medial-lateral (ML) and anterior-posterior (AP) ranges were also found in the KT group (median = −0.15% foot width (FW) & median = −0.28% foot length (FL)) than those of the Cn group (median = 0.67% FW& median = 0.88% FL). Conclusions: Ankle braces might hamper the ability to absorb the impact force during landing. On the other hand, Kinesio tape might be beneficial for the postural control during landing.
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Müller, Roy, i Emanuel Andrada. "Skipping on uneven ground: trailing leg adjustments simplify control and enhance robustness". Royal Society Open Science 5, nr 1 (styczeń 2018): 172114. http://dx.doi.org/10.1098/rsos.172114.
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It is known that humans intentionally choose skipping in special situations, e.g. when descending stairs or when moving in environments with lower gravity than on Earth. Although those situations involve uneven locomotion, the dynamics of human skipping on uneven ground have not yet been addressed. To find the reasons that may motivate this gait, we combined experimental data on humans with numerical simulations on a bipedal spring-loaded inverted pendulum model (BSLIP). To drive the model, the following parameters were estimated from nine subjects skipping across a single drop in ground level: leg lengths at touchdown, leg stiffness of both legs, aperture angle between legs, trailing leg angle at touchdown (leg landing first after flight phase), and trailing leg retraction speed. We found that leg adjustments in humans occur mostly in the trailing leg (low to moderate leg retraction during swing phase, reduced trailing leg stiffness, and flatter trailing leg angle at lowered touchdown). When transferring these leg adjustments to the BSLIP model, the capacity of the model to cope with sudden-drop perturbations increased.
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ARAI, Takahiro, i Hiroichi MIAKI. "Kinematic Analysis of a Single Leg Drop Landing for Various Static Alignments of the Knee". Rigakuryoho kagaku 27, nr 6 (2012): 657–60. http://dx.doi.org/10.1589/rika.27.657.
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Sams, Alexis, Evangelos Pappas i Marshall Hagins. "The Effects of Inclined Surfaces on Pre-landing EMG Activity During Single-leg Drop Jumps". Medicine & Science in Sports & Exercise 40, Supplement (maj 2008): S298. http://dx.doi.org/10.1249/01.mss.0000323617.75955.a2.
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DiCesare, Christopher A., Nathaniel A. Bates, Kim D. Barber Foss, Staci M. Thomas, Samuel C. Wordeman, Dai Sugimoto, Benjamin D. Roewer i in. "Reliability of 3-Dimensional Measures of Single-Leg Cross Drop Landing Across 3 Different Institutions". Orthopaedic Journal of Sports Medicine 3, nr 12 (16.12.2015): 232596711561790. http://dx.doi.org/10.1177/2325967115617905.
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Tamura, Akihiro, Kiyokazu Akasaka i Takahiro Otsudo. "Lower-Extremity Energy Absorption During Side-Step Maneuvers in Females With Knee Valgus Alignment". Journal of Sport Rehabilitation 29, nr 2 (1.02.2020): 186–91. http://dx.doi.org/10.1123/jsr.2018-0281.
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Context: Excessive knee valgus on landing can cause anterior cruciate ligament injury. Therefore, knee valgus alignment may show characteristic energy absorption patterns during landings with lateral movement that impose greater impact forces on the knee joint compared with landings in other alignments. Objective: To investigate the energy absorption strategy in lower-extremities during side steps in females with knee valgus alignment. Design: Controlled laboratory study. Setting: University research laboratory. Participants: A total of 34 female college students participated in this experiment. Interventions: Participants performed single-leg drop vertical jump and side steps. All participants were divided into valgus (n = 13), neutral (n = 9), and varus (n = 12) groups according to knee position during landing in single-leg drop vertical jumps. Main Outcome Measures: Lower-extremity joint angles, moments, and negative works were calculated during landing in side steps, and 1-way analysis of variance and post hoc tests were used to determine between-group differences. Results: Negative works of hip extensors, knee abductors, and ankle plantar flexors during landing in side steps were significantly smaller in the valgus than in the varus group; however, negative work of the knee extensors was significantly greater in the valgus group than in varus group. Conclusions: The findings of this study indicated that landing with knee valgus induced the characteristic energy absorption strategy in the lower-extremity. Knee extensors contributed more to energy absorption when landing in knee valgus than in knee varus alignment. Learning to land in knee varus alignment might reduce the impact on the knee joint by increasing the energy absorption capacities of hip extensors, knee abductors, and ankle plantar flexors.
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Ithurburn, Matthew P., Mark V. Paterno, Kevin R. Ford, Timothy E. Hewett i Laura C. Schmitt. "Young Athletes After Anterior Cruciate Ligament Reconstruction With Single-Leg Landing Asymmetries at the Time of Return to Sport Demonstrate Decreased Knee Function 2 Years Later". American Journal of Sports Medicine 45, nr 11 (23.06.2017): 2604–13. http://dx.doi.org/10.1177/0363546517708996.
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Background: Previous work shows that young athletes after anterior cruciate ligament reconstruction (ACLR) demonstrate single-leg (SL) landing movement asymmetries at the time of return to sport (RTS); however, the effect of movement asymmetries on longitudinal knee-related function after ACLR has not been examined. Hypothesis/Purpose: The purpose of this study was to examine the effect of SL drop-landing movement symmetry at the time of RTS on knee-related function 2 years later in young athletes after ACLR. The first hypothesis was that young athletes who demonstrated SL drop-landing asymmetries at RTS would demonstrate decreased knee function 2 years later compared with those who demonstrated symmetric SL drop-landing mechanics. The second hypothesis was that SL drop-landing movement symmetry at RTS would be associated with knee functional recovery 2 years later. Study Design: Cohort study; Level of evidence, 2. Methods: This study included 48 young athletes who had undergone ACLR and were assessed at the time of RTS (77% female; mean [±SD] age at RTS, 17.6 ± 2.6 years) and followed for 2 years after RTS. Three sagittal-plane landing variables of interest were calculated using 3-dimensional motion analysis during an SL drop-landing task at the time of RTS: knee flexion excursion, peak internal knee extension moment, and peak trunk flexion. The limb symmetry index (LSI) was calculated for each landing variable using the following: LSI = (involved/uninvolved) × 100%. The LSI was used to divide the cohort into symmetric (SYM) and asymmetric (ASYM) groups for each landing variable: knee flexion excursion (SYM: LSI ≥ 90% [n = 23]; ASYM: LSI < 85% [n = 18]), peak internal knee extension moment (SYM: LSI ≥ 90% [n = 19]; ASYM: LSI < 85% [n = 22]), and peak trunk flexion (SYM: LSI ≤ 105% [n = 25]; ASYM: LSI > 115% [n = 19]). At 2 years after RTS, knee-related function was evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) subjective knee form, and performance on SL hop tests. Functional recovery was defined based on literature cutoffs for knee-related functional measures. Differences in 2-year function were compared between the symmetry groups using Mann-Whitney U tests because of nonnormality. Logistic regression was used to determine if landing symmetry at the time of RTS would be associated with 2-year knee functional recovery after RTS. Results: The ASYM knee flexion excursion group demonstrated decreased function at 2 years after RTS compared with the SYM group on the KOOS-Pain (ASYM: 93.0 ± 8.2; SYM: 98.4 ± 3.0; P = .008) and the KOOS–Quality of Life (ASYM: 81.6 ± 16.1; SYM: 94.1 ± 9.7; P = .008). Knee flexion excursion was associated with knee functional recovery on the KOOS-Pain and the KOOS–Quality of Life ( P = .033 and P = .012, respectively) at 2 years after RTS, after controlling for the quadriceps strength LSI and graft type. Conclusion: Young athletes after ACLR with asymmetries in knee kinematics at the time of RTS reported decreased self-reported function 2 years later; however, the clinical importance of these differences needs to be further understood.
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Szlachta, Grzegorz, Rafał Gnat i Maciej Biały. "Reliability of 3D measurement of pelvic and lower limb kinematics during two single leg landing tasks". Biomedical Human Kinetics 13, nr 1 (1.01.2021): 73–80. http://dx.doi.org/10.2478/bhk-2021-0010.
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Abstract Study aim: Three-dimensional (3D) motion analysis is one of the available methods used to evaluate body kinematics. The aim of this study was to assess the intrarater reliability of measurement of pelvic and lower limb kinematics during two single leg landing tasks using 3D motion analysis. Material and methods: 19 healthy volunteers (8 women, 11 men, age 23.1 ± 2.8 years, weight 70.7 ± 9.2 kg, height 174.8 ± 6.7 cm) performed five repeated single leg hurdle hops (SLHH) (30 cm height) and five single leg drop landings (SLDL) from a box (40 cm height) in one measurement session with a 15-minute break and after marker replacement with 3D assessment. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), and the smallest detectable differences (SDD) were used to examine the reliability of kinematic parameters during the landing phase. Results: The average intrarater ICC for SLHH was 0.92 (SEM = 1.69°, SDD 4.68°) and for SLDL was 0.96 (SEM = 0.81°, SDD = 2.26°). After marker replacement ICC decreased to an average value of 0.81 (SEM = 2.05°, SDD 5.68°) for SLHH and 0.82 (SEM = 2.36°, SDD 6.53°) for SLDL. Conclusions: Using the 3D method to evaluate pelvis and lower limb kinematics during single leg landing in one measurement session is a high reliability method for most parameters. Marker replacement is one of the factors that reduce the reliability of measures. When applying the SEM and SDD values, which the present paper contains, it is worth mentioning that the obtained results are caused by measurement error or they are due to individual issues.
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Janosky, Joseph J., Brandon Schneider, Daphne Ling, James Russomano, Naomi Roselaar, Caroline Boyle, James Kinderknecht i Robert G. Marx. "EFFECTS OF NEUROMUSCULAR TRAINING ON BIOMECHANICAL EFFICIENCY IN HIGH SCHOOL ATHLETES". Orthopaedic Journal of Sports Medicine 8, nr 4_suppl3 (1.04.2020): 2325967120S0014. http://dx.doi.org/10.1177/2325967120s00148.
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Background: Anterior cruciate ligament (ACL) injuries are among the most common and devastating sports-related knee injuries. Neuromuscular training (NMT) has demonstrated efficacy as a preventive intervention for ACL injury and has been associated with improvements in measures of sports performance, but the specific physiologic mechanisms that serve as protective factors and contribute to improved performance haven not been well-defined. Hypothesis/Purpose: The purpose of this study is to investigate the association between NMT and biomechanical efficiency among high school athletes. We hypothesized that the performance of NMT is associated with improved biomechanical efficiency during the performance of fundamental movements and agility tests when compared to a group of untrained control subjects. Methods: Eight high school soccer and basketball teams (111 athletes, 53.1% male, mean age 15.6 years) were recruited and assigned to either an intervention or control group. The intervention group performed NMT as part of their warm-up prior to each practice and competition for 12 weeks. NMT was administered by experienced sports medicine clinicians who provided exercise instruction, technique cues, and performance feedback throughout each training session. The control group performed their customary warm-up under the direction of the team’s coaches. Biomechanical efficiency was assessed through performance of static and dynamic tests using an FDA-approved wireless sensor system. Agility was assessed using a timed three-cone agility test. All tests were administered immediately prior to and following each competitive sports season. Results: Matched pre-/post-season data was collected from 74 athletes (67%). Significant improvements [point estimate (95% CI) p-value] were observed in the intervention group for left lower extremity [0.25 (0.06,0.45) p = 0.01] and right lower extremity [0.21 (0.05,0.37) p = 0.01] loading/landing speed ratios during a single leg hop test, left lower extremity [-136.34 (-225.74,-46.95) p = 0.003] and right lower extremity [-110 (-211.36,-8.64) p = 0.03] ground reaction force, left lower extremity [-1.03, (-.189,-0.18) p = 0.02] and right lower extremity [-0.94 (-1.73,-0.14) p = 0.02] initial peak acceleration, and cadence [-12.12 (-21.60,-2.65) p = 0.01] during a straight-line running acceleration/deceleration test, and time [0.51 (0.24,0.78) p = 0.0003] during a three-cone agility test. Conclusion: Results demonstrate that season-long, sport-specific, age-appropriate NMT administered by sports medicine clinicians can significantly improve biomechanical efficiency during the performance of fundamental movements and agility tests by high school athletes. To achieve similar results, sports coaches should be trained to provide exercise instruction, technique cues, and performance feedback when administering NMT in real-world settings. [Table: see text][Table: see text]
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Fransz, Duncan P., Arnold Huurnink, Idsart Kingma i Jaap H. van Dieën. "How does postural stability following a single leg drop jump landing task relate to postural stability during a single leg stance balance task?" Journal of Biomechanics 47, nr 12 (wrzesień 2014): 3248–53. http://dx.doi.org/10.1016/j.jbiomech.2014.06.019.
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