Academic literature on the topic 'Single leg drop-landing exercise'
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Journal articles on the topic "Single leg drop-landing exercise"
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Wiebe, Peter N., Cameron J. R. Blimkie, Nathalie Farpour-Lambert, Julie Briody, Damian Marsh, Allan Kemp, Chris Cowell, and 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, no. 2 (May 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, and 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, no. 10 (May 22, 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, and 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, no. 10 (May 15, 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, and 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, no. 3 (November 9, 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, and 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, no. 1 (January 1, 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, and S. Jayne Garland. "Retraining Postural Responses With Exercises Emphasizing Speed Poststroke." Physical Therapy 92, no. 7 (March 15, 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, and 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, no. 21 (November 6, 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, and 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, no. 7 (September 1, 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, and Lauren C. Benson. "The Effect of Isolated Hamstrings Fatigue on Landing and Cutting Mechanics." Journal of Applied Biomechanics 31, no. 4 (August 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, and 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, no. 1 (January 3, 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.
Dissertations / Theses on the topic "Single leg drop-landing exercise"
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Wiebe, Peter N., and res cand@acu edu au. "Effects of Different Loading Intensities on Skeletal Adaptation to Exercise in Prepubertal Girls." Australian Catholic University. School of Exercise Science, 2004. http://dlibrary.acu.edu.au/digitaltheses/public/adt-acuvp62.29082005.
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This study involved a 28-week school-based exercise trial of single-leg drop-landing exercise with 42 girls (Tanner stage 1; 6-10 yr old) 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 and 28cm, respectively using the non-dominant leg. Single-leg peak ground-reaction impact forces (PGRIF) in a sub-sample ranged between 2.5 – 4.4 x body-weight (BW). No differences (p>0.05) among groups at baseline for age, stature, lean tissue mass (LTM - DXA - Lunar 3.6-DPX), leisure time physical activity or average daily calcium intake were detected. No significant within group changes for between leg differences from baseline to post-training and no significant differences among groups at baseline, or in magnitude of change for any of the dominant or non-dominant (loaded) leg bone mineral content (BMC g) measures determined by DXA – loaded leg total - 19.06, 25.5, 25.46 [p=.156], femoral neck - 0.14, 0.11, 0.15 [p=.959], greater trochanter - 0.37, 0.06, 0.26 [p=.733], mid femoral shaft - 3.87, 3.87, 3.42 [p=.677] for the C, LD and HD groups, respectively, after adjusting for the covariates baseline body and fat mass, and change in LTM (ANCOVA) were observed. Similarly, following ANCOVA adjustments no significant differences for changes in calcaneal speed of sound and broadband ultrasound attenuation (CUBA Clinical), DXA derived changes in femoral neck (-0.009, 0.033, -0.009; p=.189) and total MFS (0.029, 0.041, 0.053; p=.447) volumetric BMD (g.cm-3), or MFS cortical volumetric BMD, the latter derived by a new technique combining MRI and DXA were identified. TBBMC changed by 79.6g-C, 100.2g-LD and 91.9g-HD (p=.339). Combining data from both exercise groups to increase statistical power produced similar results. No significant within group changes for between leg differences from baseline to post-training and no significant differences among groups at baseline, or in magnitude of change for any of the dominant or non-dominant (loaded) leg bone geometrical (area cm2) determined by MRI using ANALYZE® software of proximal - 22.18, 12.91, 19.86 [p=.248], mid - 19.83, 15.91, 19.64 [p=.233], or distal - 14.78, 16.07, 13.35 [p=.792], slice cortical area for the C, LD and HD groups, respectively, after adjusting for the covariates baseline body and fat mass, and change in LTM (ANCOVA) were detected. Similarly there were no significant biomechanical cross sectional moment of inertia (CSMI cm4) changes determined by Scion Image® (Frederick, Maryland: Version-Beta 3B) and a custom macro program of proximal - 896, 815, 649 [p=.415], mid - 1054, 806, 1087 [p=.471], or distal - 1197, 1079, 966 [p=.606], slice CSMI for the C, LD and HD groups, respectively after adjusting for the same covariates. In contrast to some recent reports, our findings suggest that strictly controlled uni-modal; uni-directional 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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Janse, van Rensburg Lienke. "Pelvic kinematics during single-leg drop-landing in sports participants with chronic groin pain." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86697.
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Thesis (MScPhysio)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Introduction: Chronic groin injuries are common among athletes and have the potential to lead to chronic and career-ending pain. There is no evidence available whether pelvic kinematics can be perceived as a risk factor in developing chronic groin pain in sport or be the cause of further injuries of the lower quadrant or lumbar spine. Objective: The purpose of this study was to determine if there are any differences in pelvic kinematics of active sports participants with chronic groin pain compared to healthy controls during a single-leg drop-landing. Methodology: A descriptive study was conducted. The three-dimensional (3D) pelvic kinematics of ten cases with chronic groin pain and ten asymptomatic controls was analyzed. Pelvic kinematics was analyzed at the FNB 3D Vicon Laboratory at Stellenbosch University using an eight camera Vicon system. A physical examination, including functional movements, posture analysis, hip, knee and ankle passive range of motion measurements, sacro-iliac tests and anthropometric measurements was done by two physiotherapists prior to the 3D analysis. To analyze the pelvic kinematics, each participant performed six single-leg drop-landings. The main outcome measure was 3D pelvic kinematics at initial foot contact (IFC) and foot contact at lowest vertical position (LVP). The following sub-groups were analyzed: seven with unilateral groin pain and three with bilateral groin pain; the latter was further divided into those with the most painful leg and the least painful leg. Mean and standard deviations (SD) for pelvic kinematics were calculated and significant differences between sub-groups were determined using two-tailed Student’s t-tests. The Cohen’s D effect size calculator was used to calculate the effect size of significant differences in pelvic kinematics between case and control groups. Results: The findings indicated a significant difference (p=0.03) in frontal plane pelvic kinematics at IFC for the unilateral group. The most painful groin group showed significant differences at IFC (p=0.004) and at LVP (p=0.04) in the frontal plane pelvic kinematics. The least painful groin group showed a significant difference at LVP (p=0.01). All cases landed with pelvic downward lateral tilt during the landing phase compared to matched controls. The groin pain group with bilateral pain showed significant differences at IFC (p < 0.001) and LVP (p=0.005) for the most painful groin; and the least painful groin at IFC (p=0.01) and LVP (p=0.01) in the sagittal plane pelvic kinematics. The bilateral groin pain group showed an increase of anterior pelvic tilt in the sagittal plane during the landing phase when compared to matched controls. Increased internal pelvic rotation in the transverse plane was significant for the unilateral group at IFC (p=0.04) and for the most painful groin group at IFC (p < 0.001) and LVP (p < 0.001) compared to matched controls. Conclusion: Results from this study shows that pelvic kinematic changes in the frontal, sagittal and transverse planes do occur in patients with chronic groin pain when compared to controls. This may imply that muscle weakness around the hip and pelvis may contribute to the development of chronic groin pain in active sports participants. Rehabilitation of these muscles should be taken into consideration when treating patients with chronic groin injuries. Further research should be focused on muscular recruitment patterns in sports participants with groin pain to critically define the muscular causal factors in more depth.
AFRIKAANSE OPSOMMING: Inleiding: Kroniese lies beserings is ‘n algemene verskynsel onder die aktiewe sport populasie. Dit mag tot kroniese pyn lei en het die potensiaal om ‘n sport loopbaan te be-eindig. Tans, is daar geen verdere navorsing beskikbaar oor die invloed van bekken kinematika op onderste ledemaat beserings asook die moontlike oorsaak tot kroniese lies pyn in atlete nie. Oogmerk: Die doel van hierdie studie was om vas te stel watter verskille in die bekken kinematika ontstaan tussen aktiewe sport deelnemers met kroniese lies pyn teenoor aktiewe sport deelnemers sonder enige pyn of beserings tydens ‘n enkel been aftrap beweging. Metodologie: Tien deelnemers met kroniese lies pyn en tien asimptomatiese deelnemers is gebruik om die verskille tussen die 3D bekken kinematika te bepaal. Die FNB 3D Vicon Lab by die Stellenbosch Universiteit is gebruik vir die data analise en insameling. Deelnemers het ‘n fisiese ondersoek ondergaan wat die voglende ingesluit het: funksionele bewegings, postuur analise, omvang van beweging van die heup, knie en enkel, toetse ter uitsluiting van die ilio-sakrale gewrig asook antropometriese aftmetings. Elke deelnemer is versoek om ses enkel-been aftrap sessies te doen. Die hoof uitkomsmeting was die bekken hoeke in the frontale vlak by inisiële voet kontak (IVK) asook die voet kontak teen die laagste vertikale posisie (LVP). Resultate: Die resultate wys ’n beduidende verskil (p=0.03) in die frontale vlak vir bekken kinematika by IVK vir die unilaterale groep. Die mees geaffekteerde been wys ’n beduidende verskil by IVK (p=0.004) en by LVK (p=0.04) in die frontale vlak vir bekken kinematika. Die groep met die minste geaffekteerde been toon ’n beduidende verskil by LVP (p=0.01). Alle simptomatiese deelnemers het met die bekken in afwaartse bekken kanteling geland tydens die landings fase. Die groep met bilaterale pyn toon ’n beduidende verskil by IVK (p < 0.001) en by LVP (p=0.005) vir die mees geaffekteerde been en vir die minste geaffekteerde been by IVK (p=0.01) en LVP (0.01) in die sagittale vlak vir bekken kinematika. Die bilaterale groep met kroniese lies pyn land met meer anterior bekken kanteling in die sagittale vlak gedurende die landings fase teenoor die asimptomatiese groep. Interne bekken rotasie was beduidend meer vir die unilaterale groep by IVK (p=0.04) en vir die mees geaffekteerde been by IVK (p < 0.001) en LVP (p < 0.001) teenoor asimptomatiese deelnemers. Gevolgtrekking: Die resultate van hierdie studie bewys dat daar wel ‘n verskil is in die bekken kinematika van deelnemers met kroniese lies pyn teenoor asimptomatiese deelnemers. Hierdie verskille is waarneembaar in die frontale, sagittale en transverse vlakke. Dit impliseer dat spier swakheid van die bekken en heup spiere ‘n bydrae mag he tot die ontwikkeling van kroniese lies beserings in atlete. Rehabilitasie van bogenoemde spiere is belangrik in die behandeling van kroniese lies beserings. Verdere navorsing oor spier aktiverings patrone in aktiewe, sports deelnemers met kroniese lies pyn word benodig, om die oorsprongs faktore te ondersoek.
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Eckburg, Meredith L. "Sex and Foot Posture Affects Ground Reaction Forces during a Single-leg Drop Landing." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1212624080.
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Visser-Maritz, Karien. "Knee kinematics during a single-leg drop-landing in sports participants with chronic groin pain." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86507.
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Thesis (MScPhysio)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Introduction: Groin injuries are among the top six injuries in contact sports and may lead to career ending chronic pain. Research on the role of knee kinematics in developing chronic groin pain in sport is scarce. Objective: The purpose of this study was to determine if there are differences in knee kinematics during a single-leg drop-landing in sports participants with chronic groin pain compared to asymptomatic controls. Methodology: A descriptive study was conducted. Twenty active sports’ participants were recruited from soccer and rugby clubs situated around the Cape Peninsula area, Western Cape, South Africa. The three-dimensional (3D) knee kinematics of ten cases with chronic groin pain and ten asymptomatic controls was analysed. Knee kinematics was analysed in the FNB-3D Vicon Laboratory at Stellenbosch University, using an eight camera Vicon system. A positive adductor squeeze test was used as a diagnostic test to include cases with chronic groin pain. Each participant performed six single-leg drop landings. The main outcome measure was 3D knee kinematics at initial foot contact and at the lowest vertical position of the drop landing. The following sub-groups were analysed: seven unilateral groin pain cases compared to their seven matched controls; three bilateral groin pain cases where their most painful leg and least painful leg were compared to their matched controls, respectively. Descriptive statistical techniques were used for all outcome measures; means and standard deviations (SD) were calculated, followed by a Student’s t-test to determine significant differences between the cases and controls. For all outcomes with p-values equal to or below 0.05, the effect size was calculated using the Cohen’s D. Results: The findings of this study indicated a significant difference (p=0.0001) between cases with unilateral groin pain having less knee internal rotation compared to the controls at the lowest vertical position of the drop landing in the transverse plane. Significantly less internal rotation (p<0.0001), was also noted in the cases with bilateral groin pain (in the most painful leg and the less painful leg), although this was noted at foot contact. Cases with bilateral groin pain also had significantly (p<0.001) more knee varus (adduction) during the landing phase. Conclusion: Differences in knee kinematics between sports participants with chronic groin pain and asymptomatic controls were found. These findings imply that the knee joint should be included during assessment and rehabilitation of individuals suffering with chronic groin pain. Due to the cross-sectional study design of the current study, it cannot be stated for certain whether the knee kinematics noted in the groin pain group are causative or as a result of groin pain. Future prospective studies are thus recommended; these studies should focus on the effect of contralateral knee kinematics on the hip adductors and may include exploration of the muscular components during a single-leg drop landing.
AFRIKAANSE OPSOMMING: Inleiding: Lies beserings is een van die top ses beserings in kontak sport en kan lei tot chroniese lies pyn en selfs die be-eindigging van ‘n sportloopbaan. Navorsing oor die rol van knie kinematika in die ontwikkeling van chroniese liesbeserings in sport is skaars. Doelwit: Die doel van hierdie studie was om te bepaal of daar verskille in die knie kinematika is tydens 'n enkel been val landing in sport deelnemers met chroniese lies pyn in vergelyking met gesonde kontroles. Metode: 'n Beskrywende studie was uitgevoer. Twintig aktiewe sport deelnemers is gewerf van rugby en sokker sportklubs geleë rondom die Kaapse Skiereiland, Wes-Kaap, Suid-Afrika. Die 3D knie kinematika van tien gevalle met chroniese lies pyn en tien asimptomatiese bypassende kontroles is ontleed. Knie kinematika was ontleed in die FNB-3D Vicon Laboratorium by die Universiteit van Stellenbosch, met behulp van 'n agt-kamera Vicon stelsel. 'n Positiewe Adduktor druk toets was gebruik as 'n diagnostiese toets om gevalle met chroniese lies pyn in te sluit. Om die knie kinematika te analiseer, het elke deelnemer ses enkel been val landings uitgevoer . Die belangrikste uitkomsmeting was 3D knie kinematika by die aanvanklike voet kontak en by die laagste vertikale posisie van die enkel-been val landing. Die volgende sub-groepe was ontleed: sewe unilaterale lies pyn gevalle in vergelyking met hul sewe bypassende kontroles; drie bilaterale lies pyn gevalle waar hul mees pynlike been, sowel as minder pynlike been onderskeidelik vergelyk was met hul bypassende kontroles. Beskrywende statistiese tegnieke was gebruik vir alle uitkoms maatreëls; gemiddeldes en standaardafwykings (SA) was bereken, gevolg deur 'n Studente’s t-toets om beduidende verskille tussen die gevalle en kontroles te bepaal. Vir al die uitkomste met p-waardes gelyk of onder 0.05, is die effekgrootte bereken deur die Cohen’s D. Resultate: Die bevindings van hierdie studie dui op 'n beduidende verskil (p=0,0001) tussen gevalle met unilaterale lies pyn met minder interne knie rotasie in vergelyking met die kontroles by die laagste vertikale posisie van die val landing in die dwars vlak. Aansienlik minder interne rotasie (p<0,0001), is ook opgemerk in gevalle met bilaterale lies pyn (in die mees pynlike been en die minder pynlik been), alhoewel tydens voet kontak. Gevalle met bilaterale lies pyn het ook betekenisvol (p <0.001) meer knie varus (adduksie) tydens die landingsfase gehad. Gevolgtrekking: Verskille bestaan in die knie kinematika tussen sport deelnemers met chroniese liesbesering pyn en gesonde kontroles. Hierdie bevindinge impliseer dat die knie behoort ingesluit te word tydens die assessering en rehabilitasie van individue met chroniese lies pyn. As gevolg van die deursnee-studie ontwerp van hierdie studie, kan dit nie bevestig word of die knie kinematika die oorsaak van die chroniese pyn is nie. Toekomstige voornemende studies word dus aanbeveel, hierdie studies moet fokus op die effek van die kinematika van die kontralaterale knie op die heup adduktore en kan moontlik die ondersoek van die spier kinetika tydens hierdie aktiwiteit insluit.
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Dare, Michael Robert. "Investigation of hip kinematics in adult sports participants during single leg drop landing with chronic groin pain." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86334.
Full textAbstract:
Thesis (MScPhysio)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Introduction-Groin injuries are among the top six most cited injuries in soccer and account for 10-18 per cent of all injuries reported in contact sport. Groin pain can result from a variety of pathologies, but according to literature, 63 per cent of groin pain is due to adductor pathology. Objective-The objective of this study was to explore if there are kinematic differences in the hip joint in sports participants with groin pain compared to matched healthy controls. Study design A cross sectional, descriptive study was conducted. Study setting-The study was conducted at the FNB -3D motion analysis laboratory at the University of Stellenbosch, South Africa. Outcome variables-The dependent variables included hip kinematics in the sagittal, frontal and transverse planes at foot strike, lowest vertical point of the pelvis and total range of hip motion during a single leg drop landing. Methodology-The study sample comprised 20 male club level soccer-and, rugby players, running and cycling participants between the ages of 18-55 years of age. Ten of the subjects had chronic groin pain and the other ten were healthy matched controls. An eight-camera Vicon system was used to analyse the kinematics of the hip joint during single leg drop landing. For the purpose of comparison, the data was analysed for participants with unilateral groin pain and matched controls (n=14) and participants with bilateral groin pain and controls (n=6). The full set of data was subdivided for analysis into three distinct sub-groups. Unilaterally injured groin cases (n=7) were matched with seven healthy controls for analysis. Bilaterally injured groin cases (n=3) were matched with three healthy controls. Results-Cases with unilateral groin pain at initial contact had significantly more abduction of the hip joint when compared to controls (p<0.05). The effect size of this difference was large (0.94). Cases with unilateral groin pain also demonstrated greater hip internal rotation while the controls had external rotation (p<0.05) during a drop landing activity. Bilaterally injured groin cases landed with significantly (p=?) greater ranges of hip flexion as well as in significantly (p=?) more hip abduction during a drop landing activity. They also demonstrated greater total range of motion in the frontal plan when compared to controls. Groin pain cases overall demonstrated greater ranges of motion and tended to land in more abduction compared to controls. Conclusion-This study found that during a single leg drop landing, sports participants with unilateral chronic groin pain landed with significantly greater hip abduction and exhibited larger total range of motion in the transverse plane, which may indicate impaired stability of the hip complex when compared to controls.
AFRIKAANSE OPSOMMING: Inleiding-Liesbeserings is een van die top ses mees prominente sokker beserings. Dit beloop 10-18 persent van alle beserings wat in kontaksport aangemeld word. Liespyn kan die gevolg wees van ‘n verskeidenheid patologië, maar volgens die literatuur is 63 persent van liespyn as gevolg adduktor patologie. Doelwitte-Die doelwit van hierdie studie was om ondersoek in te stel of daar enige kinematiese veranderinge in die heupgewrig is in spelers met liespyn in vergelyking met dieselfde vergelykbare spelers sonder liespyn. Studie Ontwerp-‘n Deursnit, beskrywende studie was onderneem. Studie Omgewing-Die studie was uitgevoer by die FNB-3D bewegingsanalise laboratorium van die Stellenbosch Universiteit, Suid-Afrika. Uitkomsveranderlikes-Die afhanklike veranderlikes het in gesluit die heup kinematika in die sagitale, frontale en transvers vlakke met voet kontak endie laagste vertikale punt van die pelvis sowel as die totale heup omvang van beweging gedurende een been landing. Metodologie-Die studie populasie het bestaan uit 20 manlike sokker- en, rugbyspelers, hardlopers en fietsryers tussen die ouderdomme van 18 en 55 jaar. Tien van die deelnemers het kroniese liespyn gehad en die ander tien in die gelyke gesonde groep was sonder liespyn. Die agt kamera Vicon sisteem was gebruik om die kinematika van die heupgewrig te analseer tydens een been landing. Vir die doel om ‘n vergelyking te kan maak, was die data geanaliseer van deelnemers met unilaterale liespyn en die vergelykende groep sonder liespyn (n=14) en deelnemers met bilaterale liespyn en hulle vergelykende groep sonder liespyn (n=6).. Die volledige stel data was onderverdeel in drie afsonderlike sub groepe. Vir die analiese was unilaterale liesbeserings (n=7) vergelyk met sewe deelnemers sonder liespyn in die kontrolegroep. Deelnemers met bilaterale liesbeserings (n=3) was vergelyk met drie in die kontrolegroep. Resultate-Die deelnemers met unilaterale liespyn het met eerste kontak beduidend meer abduksie van die heupgewrig gehad in vergelyking met die kontrolegroep (p<0.05). Die effek van hierdie verskil was groot (0.94). Die deelnemers met unilaterale liespyn het ook ‘n grooter interne rotasie getoon, terwyl die kontrole groep meer eksterne rotasie gedemonstreer het (p<0.05) met landing. Deelnemers met bilaterale liespyn het beduidend (p=?) meer heup fleksie en abduksie omvang van beweging tydens landing. Hulle het ook ‘n groter totale heup omvang van beweging in die frontale vlak gehad in vergelyking met die kontrolegroep. Deelnemers met liespyn het oor die algemeen ‘n grooter omvang van beweging getoon, en was geneig om met meer abduksie van die heup te land as die kontrolegroep. Gevolgtrekking-Die studie toon dat deelnemers met kroniese unilaterale liespyn, tydens een been landing, beduidende meerheup abduksie toon en dat die heup in die transverse vlak meer totale omvang van beweging gebruik wat kan dui op onstabiliteit in die heupkompleks in vergelyking met die kontrolegroep.
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Harwin, Lauren Sandra. "Ankle kinematics and ground reaction force during single leg drop landing in sports participants with chronic groin pain." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86520.
Full textAbstract:
Thesis (MScPhysio)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Aims: This study aims to ascertain if there are differences in ankle kinematics and ground reaction force in sports participants with chronic groin pain compared to healthy controls. Methods: A cross sectional descriptive study design was used. Twenty participants - 10 cases with chronic groin pain and 10 healthy controls participated. The 10 cases included participants with unilateral pain (n=7) and bilateral pain (n=3). For analysis, the bilateral pain group was divided into the most and less painful side. The study was conducted at the FNB 3D Motion Analysis Laboratory, Stellenbosch University. Sagittal plane kinematics and VGRF was analysed during a single leg drop landing. Results: The group with unilateral groin pain had a higher peak force compared to the matched side of the controls. The bilateral pain groups had less plantarflexion at foot contact (most affected p=<0.001; least affected p=<0.001) and total range of motion (p=<0.05) compared to the control group. The bilaterally injured groin pain groups demonstrated less peak force when compared to controls. Conclusion: This is the first study to indicate alterations in ankle kinematics and VGRF and that these changes are more apparent in sports participants with bilateral pain. Less range of motion during the landing task illustrated by the bilateral pain group suggests less effective force absorption of the distal segments. In the bilateral groups it suggests that force attenuation may have occurred high up the kinetic chain which may place more strain on the groin. Clinically rehabilitation of the athlete with chronic groin pain should include the distal segments of the lower limb. Further research should be conducted in larger groups.
AFRIKAANSE OPSOMMING: Doelstellings: Hierdie studie poog om vas te stel of daar verskille in enkelbeweging en grondvloer-reaksiekrag is in deelnemers van sport met chroniese liespyn in vergelyking met gesonde kontrole deelnemers. Metode: ‘n Deursnee beskrywende studieontwerp is gebruik. Twintig deelnemers, 10 gevalle met chroniese liespyn en 10 gesonde kontrole het deelgeneem. Die 10 gevalle het ingesluit deelnemers met eensydige pyn (n=7) en bilaterale pyn (n=3). Vir die analise, is die bilaterale pyngroep verdeel in die mees en mins geaffekteerde kant. Die studie is gedoen by die FNB3D Beweginsanalise-laboratorium, Universiteit van Stellenbosch. Sagitaal-platvlak kinematiek en vertikale reaksiekrag is geanaliseer gedurende ‘n enkele beenlanding. Resultate: Die groep met eensydige liespyn het ‘n hoër piekkrag gehad in vergelyking met dieselfde kant van die kontrolegroep. Die bilaterale pyngroep het minder plantaarfleksie met voetkontak getoon (mees geaffekteer p=<0.001; minste geaffekteer p=<0.001) en totale beweginsomvang (p=<0.05) in vergelyking met die kontrolegroep. Die bilateraal-liesbeseringsgroep het minder piekkrag getoon in vergelyking met die kontrolegroep. Gevolgtrekking: Hierdie is die eerste studie om veranderings in enkelbeweging en grondreaksiekrag aan te toon, asook dat hierdie veranderinge meer opvallend is in persone wat aan sport deelneem wat bilaterale pyn ondervind. Verminderde beweginsomvang gedurende die landingstaak deur die bilaterale pyngroep suggereer minder effektiewe kragabsorpsie van die distale segmente. In die bilaterale groep suggereer dit dat kragvermindering waarskynlik hoog op die kinematiese ketting voorgekom het wat weer meer stremming op die lies plaas. Kliniese rehabilitasie van die atleet met chroniese pyn behoort die distale segmente van die onderste ledemaat in te sluit. Verdere navorsing behoort in groter groepe uitgevoer te word.
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Morris, Tracy Louise. "Investigation of thoracic spine kinematics in adult sports participants with chronic groin pain during a single leg drop landing task." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86314.
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Thesis (MScPhysio)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Chronic groin pain is widespread across many sporting disciplines. The aim of our research was to determine if there are kinematic differences of the thoracic spine in active sports people with chronic groin pain, compared with healthy controls. A cross-sectional descriptive design was followed. Participants were required to complete six single leg drop landings with each leg from a 20cm height. The study was done in the 3D Movement Analysis Laboratory at the University of Stellenbosch. Ten male participants with unilateral or bilateral chronic groin pain of more than 3 months duration and 10 asymptomatic males, matched for age and sports participation, were recruited. The main outcome measures were: thoracic spine angle at initial foot contact, maximum thoracic spine angle, range of movement (ROM) (difference between the minimum and maximum values) and thoracic spine angle at lowest vertical point of the pelvis. This was assessed in all 3 movement planes: the sagittal plane (X plane), the coronal plane (Y plane) and the transverse plane (Z plane). The results of our study showed that for the unilaterally affected groin pain group, the cases landed in significantly more thoracic flexion (P<0.001 with large effect size) and were in significantly more thoracic flexion still at the lowest point. Peak thoracic flexion was significantly more in the cases than the controls. (P<0.001 with medium effect size) The same was true for the bilaterally affected group when landing on the most painful side, although this was not statistically significant. There were no significant differences in the frontal or transverse planes. In the bilaterally painful group, axial rotation ROM was significantly reduced when landing on either leg (worst affected side: P=0.040 with medium effect size and least affected side: p=0.006 with large effect size). The same occurred in the unilaterally affected group, although this was not statistically significant. Our study suggests that, in participants with chronic groin pain, there is greater thoracic forward flexion away from neutral during landing and that total axial rotation ROM during landing is diminished.
AFRIKAANSE OPSOMMING: Kroniese liespyn kom dikwels en in verskeie sportsoorte voor. Die doel van ons studie was om te bepaal of daar kinematiese verskille van die torakale werwelkolom is in aktiewe sportmense met chroniese liespyn, in vergelyking met gesonde kontroles. ‘n Dwars-deursnit beskrywende studiemetode is gevolg, en uitgevoer in die 3D Beweging Analise Laboratorium, Universiteit van Stellenbosch. Deelnemers moes ses landings op een been doen, met elke been, vanaf 'n 20cm hoogte. Tien mans met eensydige of bilaterale chroniese liespyn vir langer as 3 maande, en 10 asimptomatiese mans (ooreenstemmende ouderdom en sport deelname) het deelgeneem. Die hoof uitkomste wat gemeet is, was torakale werwelkolom krommingshoek by aanvanklike voet-kontak, maksimum torakale werwelkolom krommingshoek, omvang van beweging (OVB) (verskil tussen die minimum en maksimum waardes) en torakale werwelkolom krommingshoek by die laagste punt van die bekken. Dit is beoordeel in al 3 beweging vlakke: die sagittale (X) vlak, die koronale/frontale (Y) vlak en die transversale (Z) vlak. Die resultate van die studie het getoon dat, in die eensydig-geaffekteerde liespyn groep, die deelnemers in beduidend meer torakale fleksie geland het(P < 0.001, met 'n groot effekgrootte), asook met aansienlik meer torakale fleksie by die laagste punt na landing. Piek torakale fleksie was aansienlik meer in die liespyn-gevalle as in die kontroles. (P < 0.001, met middelmatige effekgrootte ) Dieselfde het vir die bilateraalgeaffekteerde groep gegeld wanneer hulle op hul mees pynlike kant geland het, hoewel dit nie statisties beduidend was nie. Daar was geen betekenisvolle verskille in die frontale of transversale vlakke van beweging nie. In die bilateraal pynlike groep, was aksiale rotasie OVB aansienlik verminder wanneer die gevalle op hul pynlikste been óf op hul minder pynlike been geland het ( mees pynlike been : P = 0,040, met 'n middelmatige effekgrootte en minder pynlike been : p = 0,006, met 'n groot effekgrootte ). Dieselfde het in die eensydig-geaffekteerde groep gebeur, hoewel dit nie statisties beduidend was nie. Ons studie dui daarop dat, in deelnemers met chroniese liespyn, daar meer torokale fleksie weg van neutraal tydens landing is en dat die totale aksiale rotasie OVB tydens die landing verminder is, in vergelyking met die kontrolegroep.
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WONG, SOON YEE, and 黃順而. "The Study of Correlation between Ankle Dorsiflexion and Ankle Stiffness during Single Leg Drop Landing." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/sjwnsa.
Full textAbstract:
碩士國立體育大學
運動保健學系
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Purpose: The purpose of the study is to examine the relationship between Ankle Dorsiflexion and Ankle Stiffness during Single Leg Drop Landing. Method: 30 active college students participated two measurements of ankle dorsiflexion, and performed 3 times single leg drop landing from a 32cm height box. Video Imaging is captured with a 100Hz high speed camera for ankle sagittal plane and collected the ground reaction force (PGRF) by BTS P-6000 force plate. The raw data is calculated by Kwon 2D software and used Excel software to analyze ankle stiffness. Result: The result of between weight-bearing lunge test (WBLT) ankle dorsiflexion measurement and ground reaction force were significantly difference(p=0.01), but not in passive straight knee ankle dorsiflexion measurement(p=0.22). There was no significant difference in the usage of percentage of plantarflexion during initial contact (IC) to PPGRF between high group and low group in passive straight knee ankle dorsiflexion measurement, but the high group and low group of WBLT were significantly difference (p=0.02). On the other hand, the usage of percentage of dorsiflexion during initial contact to peak ground reaction force between high group and low group in passive straight knee ankle dorsiflexion measurement was not significant and the high group and low group of WBLT were significantly difference (p=0.003). Eight separate Pearson bivariate correlation analyses were conducted to evaluate the relationships between ankle-dorsiflexion ROM in the 2 positions. The result of high group and low group of passive straight knee ankle dorsiflexion measurement with PGRF, TTP PGRF, the percentage of usage of dorsiflexion from IC to PPGRF, and the percentage of usage of plantarflexion from IC to PGRF were low correlation. A significant correlation in high group and low group of the percentage of usage of plantarflexion from IC to PGRF, ankle stiffness and the high group of the ankle displacement from IC to PGRF(r=0.37, r=0.32; r=0.38, r= 0.32; r=0.37). 7 variables of high and low group of kinematics and kinetics were moderately significant correlation with WBLT, its included time to PGRF(r=0.46, r=0.39), the percentage of usage of plantarflexion from IC to PGRF(r=0.58, r=0.52), the percentage of usage of dorsiflexion from IC to PGRF(r=0.41, r=0.61), the from IC to maximum dorsiflexion(r=0.45, r=0.4), ankle displacement from IC to PGRF(r=0.51, r=0.46), plantarflexion of initial contact(r=-0.47, r=-0.62), and ankle stiffness(r=-0.64, r=-0.52), and the high group and low group of ground reaction force were highly significant correlation with WBLT as well(r=-0.76, r=-0.93). Conclusion: The result indicated that, ankle dorsiflexion and ankle stiffness are pretend a critical role for reducing injuries risk. On clinical recommendation, educate a proper landing strategy is also very important which are teaching people not to over plantarflexion during landing on initial contact and heel-toes landing strategies. Lastly, WBLT is recommended for ankle dorsiflexion measurement during functional movement on experiment and practical use . Abstracts:Ankle Dorsiflexion, Ankle Stiffness, Ground Reaction Force
Conference papers on the topic "Single leg drop-landing exercise"
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Caruntu, Dumitru I., and Ricardo Moreno. "Knee Contact Characteristics During Drop Landing Exercise." In ASME 2017 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/detc2017-67614.
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This work investigates the human leg joint contact characteristics during a drop-landing exercise. The contact characteristics consist of tibio-femoral contact forces and contact point, and hip contact forces. An inverse dynamics 2-D model of human leg is used on this ballistic task in order to simplify computation. Experimental data used show a maximum of 100 degrees of flexion angle and ground reaction forces up to 4 times the body weight. All contact forces show a pattern in which they reach large magnitudes at the beginning of landing, decreasing as the subject end the exercise with a standing position.
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Caruntu, Dumitru I., Ricardo Moreno, and Robert Freeman. "Knee Muscle and Ligament Forces During Drop Landing Exercise." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70982.
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This work investigates the human leg muscle and ligaments forces during a drop-landing exercise. An inverse dynamics 2-D model of human leg is used on this ballistic task in order to predict these forces. The model consists of three bony structures, namely femur, tibia, and patella. The joints of the model are the knee joint and the hip joint. The ligamentous structure of the knee includes the two cruciate ligaments, Anterior Cruciate Ligament (ACL) and the Posterior Cruciate Ligament (PCL), and the two collateral ligaments, Lateral Collateral Ligament (LCL) and Medial Collateral Ligament (MCL). The system of muscles of the system includes muscle such as quadriceps, hamstrings, gastrocnemius are included in the model. Experimental data used show a maximum of 100 degrees of flexion angle and ground reaction forces up to 4 times the body weight. The inverse dynamics 2-D model consists of an objective function to minimize the muscle forces, and a set of constraints consisting of equality constraints which are the dynamics equations of the bony structures, and inequality constraints in which all muscle forces must be positive. All muscle forces show a pattern in which they reach large magnitudes at the beginning of landing, decreasing as the subject end the exercise with a standing position.
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Tse, Chi-Yin, Hamid Nayeb-Hashemi, Ashkan Vaziri, and Paul K. Canavan. "A Subject Specific Kinematic and Kinetic Relationship During a Single-Leg Drop Landing." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86383.
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A single-leg landing is a common type of high-risk maneuver performed by athletes. The majority of anterior cruciate ligament injury is accounted for by non-contact mechanisms, such as single-leg landings. The purpose of this study was to develop a subject specific single-leg drop landing to analyze the kinematics and kinetics of two different types of landings. Kinematic data was analyzed at five points during the landing phase: initial contact (IC), peak vertical ground reaction force (pVGRF), peak joint reaction force (pJRF), maximum knee flexion (MKF), and maximum valgus angle (MFP). A linear relationship was noted in comparing the average maximum peak vertical ground reaction force, average maximum knee flexion, and average maximum valgus angle to the platform heights in both landing styles. An increase in platform height was directly related to increased knee valgus angle in both landing styles. Significant difference (p < 0.05) was noted in the peak vertical ground reaction force between the 60% and 80% platform heights, as well as between 60% and 100% with arms above. Landing with arms across the body yielded more significant difference (p < 0.05) between platform heights in both frontal and sagittal planes. However, comparing both landing styles to each other only yielded significant difference (p < 0.05) at the 100% platform height. A valgus-varus-valgus movement was observed in all landings, and is a probable contributor to single-leg landing ACL ruptures.
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Tse, Chi-Yin, Hamid Nayeb-Hashemi, Ashkan Vaziri, and Paul K. Canavan. "A Finite Element Analysis of a Subject Specific Single-Leg Drop Landing at Varied Heights." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63716.
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The pathomechanics of knee anterior cruciate ligament (ACL) injury related to the female athlete is of high interest due to the high incidence of injury compared to males participating in the same sport. The mechanisms of ACL injury are still not completely understood, but it is known that single-leg landings, stopping and cutting at high velocity are some of the non-contact mechanisms that are causing these injuries. This study analyzed a subject specific analysis of a single-leg drop landing that was performed by a female subject at 60%, 80% and 100% of her maximum vertical jump. The femur, tibia, articular cartilage, and menisci were modeled as 3-D structures and the data collected from the motion analysis was used to obtain the knee joint contact stresses in finite element analysis (FEA). The four major ligaments of the knee were modeled as non-linear springs. Material properties of previously published studies were used to define the soft tissue structures. The articular cartilage was defined as isotropic elastic and the menisci were defined as transverse isotropic elastic. Two different styles of single-leg landings were compared to one another, resembling landing from a basketball rebound. The first landing style, single-leg arms up (SLAU), produced larger knee flexion angles at peak ground reaction forces, while single-leg arms across (SLAX) landings produced higher peak vertical ground reaction forces along with lower knee flexion angles. The mean peak vertical ground reaction force was 2.9–3.5 bodyweight for SLAU landings, while they were 3.0–3.8 for SLAX landings. The time to peak vertical ground reaction force with SLAU landings were 69 ms (60%), 60 ms (80%), and 55 ms (100%); SLAX landings were 61 ms (60%), 61 ms (80%), and 51 ms (100%).
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Chi-Yin Tse, Hamid Nayeb-Hashemi, Ashkan Vaziri, and Paul K. Canavan. "A finite element analysis of a subject specific single-leg drop landing at varied heights." In 2011 37th Annual Northeast Bioengineering Conference (NEBEC). IEEE, 2011. http://dx.doi.org/10.1109/nebc.2011.5778650.
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Tse, Chi-Yin, Ashkan Vaziri, Paul K. Canavan, Ruben Goebel, and Hamid Nayeb-Hashemi. "The Effect of Arm Position as a Comparison Between Gender During Single-Leg Landings." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-65609.
Full textAbstract:
Increased knee valgus loading has been previously identified as a possible risk factor for non-contact anterior cruciate ligament (ACL) injury. Arm position during landing may affect the risk of injury by increasing the knee valgus load. The goal of this study was to examine the kinematics and kinetics of the knee joint during single-leg drop landings from platform heights that was subject specific. Ten subjects (5 female, 5 male) were selected to participate in this single-leg landing study. No significant difference in knee kinematics was noted between arm positions, or gender. Significant difference (p < 0.05) was noted in the varus/valgus knee angle at initial contact (VVIC) when comparing the 60% vertical max jump percentage (%VJMax) to the 80% VJMax and 100% VJMax.
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Kulshreshtha, Digvijay B., and S. A. Channiwala. "Flow in Atomizers: Influence of Different Parameters on the Performance Characteristics of Plain Orifice Atomizer and Pressure Swirl Atomizer of a Fuel Injection System of Gas Turbine Combustor." In ASME 2005 Fluids Engineering Division Summer Meeting. ASMEDC, 2005. http://dx.doi.org/10.1115/fedsm2005-77122.
Full textAbstract:
The atomization process is essentially one in which bulk liquid is converted into small drops. Basically, it can be considered as a disruption of the consolidating influence of surface tension by the action of internal and external forces. In the absence of such disruptive forces, surface tension tends to pull the liquid into the form of a sphere, since this has the minimum surface energy. Liquid viscosity exerts a stabilizing influence by opposing any change in system geometry. On the other end, aerodynamic forces acting on the liquid surface may promote the disruption process by applying an external distortion force to the bulk liquid. Breakup occurs when the magnitude of the disruptive force just exceeds the consolidating surface tension force. In twin fluid atomizers of the air-blast type and air assist type, atomization and spray dispersion tend to be dominated by air momentum forces, with hydrodynamic processes playing only a secondary role. With pressure swirl nozzles, the internal flow characteristics are of primary importance, because they govern the thickness and uniformity of the annular liquid film formed in the final discharge orifice as well as the relative magnitude of the axial and tangential components of velocity of this film. It is therefore of great practical interest to examine the interrelationships that exist between internal flow characteristics, nozzle design variables, and important spray features such as cone angle and mean drop size. The various equations that have been derived for nozzle discharge coefficient are discussed because this coefficient not only affects the flow rate of any given nozzle but also can be used to calculate its velocity coefficients and spray cone angle. Consideration is also given to the complex flow situations that arise on the surface of a rotating cup or disk. These flow characteristics are of basic importance to the successful operation of atomizers, because they exercise a controlling influence on the nature of the atomization process, the quality of atomization, and distribution of drop sizes in the spray. For plain orifice atomizers, the key geometrical variables are the orifice length and diameter. Final orifice diameter is of prime importance for pressure swirl atomizers. The absence of any theoretical treatment of the atomization process has led to the evolution of empirical equations to express the relationship between the mean drop size in a spray and the variable liquid properties. This paper includes the study of different parameters that affect the flow in plain orifice and pressure swirl atomizers. The paper also includes the performance characteristics of plain orifice and pressure swirl atomizers.