Tesi: "Muscle strength"

1

Gerber, Aimee. "Determination of strength imbalance of the lower extremities". Virtual Press, 2002. http://liblink.bsu.edu/uhtbin/catkey/1231347.

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Fourteen college softball players were recruited to participate in this study to determine if a strength imbalance between the lower extremities, how significant this difference this may be and of any correlations existed among all the functional tests. Subjects took part in isokinetic flexion and extension at 60 and 240 deg/sec, parallel squats, 2-legged vertical jump, single leg vertical jump, and a five-hop test. Peak and average torque was recorded for isokinetic testing and revealed significant differences between the dominant and non-dominant limbs (13.00%- 16.00%). Peak and average force was analyzed for squats and all vertical jumps. Significance was found among all activities between dominant and non-dominant legs, other than average force for single leg vertical jump. A significant difference was also exhibited for the five-hop test between the lower extremities. Significant correlations were also found at the 0.05 and 0.01 levels amongst the various functional tests. Overall findings revealed a significant strength imbalance between the dominant and non-dominant limbs. Further research needs to be conducted in determining how detrimental these differences could be in daily performance for athletes.
School of Physical Education

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2

Gordon, Debra Anne. "Analysis of force parameters used to assess the fatigability of mammalian motor units". Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184368.

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The investigation of motor-unit fatigability in reduced-animal models has been dominated by a single fatigue test, one fatigue index, and an emphasis on changes in the magnitude of (usually peak) force. Although the standard fatigue test has been reported to elicit changes in the dynamic phases of an isometric tetanus, this has not been systematically studied in single motor units. Furthermore, changes in the profile of individual tetani during the fatigue test have led some investigators to suggest that other force parameters (i.e., integrated force) or fatigue indices may provide additional information about motor-unit performance during the test. The purposes of this project were to: (1) evaluate the time courses of a variety of force parameters characterizing both the magnitude of force and the dynamic aspects of force during a 4-min fatigue test of functionally isolated cat, tibialis posterior motor units; and (2) determine if motor units could be classified into the conventional motor-unit types based on these new parameters. There was considerable variability in the average time course of the magnitude of force during the fatigue test. The variability within the type FR and F(int) motor-unit groups resulted in several units whose characteristics bordered those which, by definition, separate unit types. The classification of these units depended on the force parameter and fatigue index used to quantify their fatigability. The time course of the magnitude of force also revealed differences in the behavior of potentiating and non-potentiating groups. There were many differences between motor-unit types in terms of dynamic-force parameters before, during and after the fatigue test. Comparison of initial and 2-min values revealed a preferential effect of stimulation on force development in type S and FR units (i.e., increased rate) and on force decay in type F(int) and FF units (i.e., prolonged duration and decreased rate). The time courses of these effects further revealed qualitative differences between different combinations of motor-unit types. Groups of units (or lack thereof) revealed by dynamic-force parameters were compared to conventional motor-unit types by discriminant analysis. The results were not always consistent with conventional types.

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3

Hamby, Derek Grady. "Chronic effects of creatine monohydrate on strength and power". Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1074541.

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The use of creative monohydrate (CM) supplementation by athletes to increase strength and lean body mass has great anecdotal support. Therefore, the purpose of this investigation was to document the chronic effects of CM supplementation on resistance trained athletes. Sixteen collegiate football players were randomly separated into a CM and placebo (P) group. Supplementation in capsule form consisted of 5 g CM or P per day throughout a 10 week resistance training program. Pre- and Post-testing consisted of 1) Weight. 2) Body fat estimation. 3) One repetition maximal bench press, squat, and power clean. 4) Cybex testing was also included. Results revealed the CM group was able to significantly increase measures of strength and power, as well as increase body mass without a change in body fat %, while the P group showed no significant changes. Data was analyzed using a paired t-test and ANCOVA (p < 0.05). CM PPrePostPrePostBody Wt (lbs)234.5 + 34.41237.37 + 31.34*215.57 ± 55.12213.0 ± 48.897-site fat %15.37+5.5116.68+6.5813.52 + 10.0913.58+8.33Bench Press (lbs)328.75 + 27.87- 340.0 + 27.65*287.14 + 58.94283.57 + 48.71Squats (lbs)532.86 + 130.92592.14 + 123.86*489.17 + 149.81512.50 ± 161.89Power Cleans271.88 + 47.73288.75 + 45.34*246.00 + 33.99241.00 + 64.65* Denotes significant measureThe data from this study supports the anecdotal claims. Further, contrary to what would be expected with long term resistance training alone, the placebo group failed to increase strength and power measures. This suggests that the resistance program lacked sufficient stimuli or that overtraining might have occurred. However, subjects ingesting CM were able to increase strength and power measures. Thus, it appears that CM may also serve as a buffer to overtraining.
School of Physical Education

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4

Weernink, Corinne M. "Heart failure and respiratory muscle strength". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0001/MQ42222.pdf.

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5

Kaya, Ryan D. "Muscle Strength, Motor Units, and Aging". Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1365769270.

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6

Short, Kevin R. "Histochemical and biochemical changes in human muscle following 17 days of unilateral lower limb suspension". Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1063203.

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The present study was undertaken to determine the relationship between perinatal complications and subsequent development of Attention Deficit Hyperactivity Disorder (ADHD) and other behavioral characteristics. The biological mothers of 74 children diagnosed with ADHD and 77 children displaying no characteristics of the disorder completed the Maternal Perinatal Scale (MPS), the Behavior Assessment System for Children-Parent Rating Scales (BASC-PRS), and a demographic survey. In addition, the biological mothers of 120 children with no characteristics of ADHD or any other behavior disorders completed only the MPS so that exploratory factor analysis of the MPS could be completed.Following factor analysis, stepwise discriminant analysis of the resulting five factors was utilized to explore the nature of the relationship between such perinatal factors and ADHD. Results of this analysis indicated that emotional factors, or the amount of stress encountered during pregnancy and the degree to Relationship Between Perinatal Complications 3 was planned, were the items that maximized the separation between the ADHD and Non-ADHD groups. Additional discrimination between the groups was attributed to the extent of insult or trauma to the developing fetus and the outcome of prior pregnancies. ADHD children were also found to have experienced twice as many behavioral, social, or medical problems, and were more likely to reach developmental milestones with delays.Stepwise discriminant analysis also revealed the Attention Problems and Hyperactivity scales of the BASC-PRS were most significant in differentiating between the ADHD and Non-ADHD subjects. Using the BASC-PRS resulted in approximately 90% of the total sample being correctly classified as ADHD or Non-ADHD. Canonical correlation analysis indicated that emotional factors and the general health of both the mother and the developing fetus were the best predictors of later behavioral patterns reported on the BASC-PRS.
Human Performance Laboratory

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7

Byrne, Christopher. "Muscle function after exercise-induced muscle damage". Thesis, Bangor University, 2001. https://research.bangor.ac.uk/portal/en/theses/muscle-function-after-exerciseinduced-muscle-damage(2bbf5fe1-f35b-4b7b-9790-ff3a04b86875).html.

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Muscle function after exercise-induced muscle damage has traditionally been evaluated by measures of isometric strength at a single joint angle or muscle length. The thesis investigates the effect of muscle damage on other muscle function parameters such as, isometric strength as a function of muscle length, concentric strength as a function of angular velocity, strength across muscle actions, the stretch-shortening cycle, power output, and fatigability. Study 1 The first part of this study aimed to determine how the muscle length at which strength is measured affects reductions in isometric strength following eccentric exercise-induced muscle damage. The damaging exercise protocol consisted of 100 maximal voluntary eccentric actions of the knee extensors, performed in the prone position through a range of motion from 40° to 140° (0° = full extension) at an angular velocity of 90 deg's-1. Isometric strength of the knee extensors was measured at short muscle length (10° knee flexion) and optimal length (80°). A significantly greater relative loss of strength was observed at short versus optimal muscle length (76.3 ± 2.5% vs. 82.1 ± 2.7% of pre-exercise values, P<0.05) over the seven day testing period following eccentric exercise. The second part of the study investigated isometric strength at optimal length and concentric strength at slow (30 deg's 1) and fast (180 deg's 1) angular velocities of movement. No differences were apparent in the magnitude and rate of recovery of strength across isometric (82.1 ± 2.7%) and slow (86.6 ± 2.0%) and fast (84.3 ± 1.5%) concentric muscle actions. Both the popping sarcomere hypothesis of 2 muscle damage and a failure in excitation-contraction coupling are possible explanations for the reduction in strength being affected by the muscle length at which it is measured. Both would be expected to affect strength to a greater extent at short versus optimal muscle lengths. Study 2 The second study investigated knee extensor muscle strength during isometric, concentric and eccentric muscle actions and vertical jump performance under conditions of squat jump (SJ), countermovement jump (CMJ) and drop jump (DJ). These measures were taken before, 1 hour after, and on days 1,2,3,4 and 7 following a damaging exercise protocol consisting of 100 barbell squats (10 sets x 10 reps @ 70% body mass load). Strength was significantly reduced for four days, however, no differences were observed in the magnitude or rate of recovery of isometric strength at 80° knee flexion and concentric and eccentric strength at 90 deg's'. Vertical jump performance was significantly reduced for three days and was dependent on the type of jump being performed. The relative decline in SJ performance was significantly greater than that in CMJ performance (91.6 ± 1.1% vs. 95.2 ± 1.3% of pre-exercise values, P<0.05) and the relative decline in SJ was significantly greater than that in DJ performance (91.6 ± 1.1% vs. 95.2 ± 1.4%, P<0.05). No differences were observed in the relative decline in CMJ and DJ performance (95.2 ± 1.3% vs. 95.2 ± 1.4%, P> 0.05). The stretch-shortening cycle (SSC) of muscle function is utilised in CMJ and DJ but not in SJ. The SSC has a clear purpose: to allow the final phase (concentric action) to take place with greater force or power output, as compared to the condition where the movement is initiated by a concentric action alone. 3 Utilisation of the SSC in performance seems to attenuate the detrimental performance effects of exercise-induced muscle damage. Study 3 The third and final study investigated the effects of exercise-induced muscle damage on maximal power output and knee extensor fatigability under isometric and dynamic conditions. Under isometric conditions, strength was assessed at 40° and 80° knee flexion and fatigability was assessed by a sustained 60s maximum voluntary contraction (MVC) at each joint angle. For dynamic conditions, maximum power output and fatigue were assessed during a maximal 30s cycle ergometer test. These measures were taken before, 1 hour after, and on days 1,2,3, and 7 following a damaging exercise protocol consisting of 100 eccentric squats (10 sets x 10 reps @ 80% concentric 1 RM). Isometric strength was significantly reduced (P < 0.05) for seven days but no significant differences were observed in the magnitude of strength loss and the pattern of recovery between the two joint angles. Fatigability was quantified as the slope (b) of a linear regression line fitted to the torque and power decay during the 60s MVC and the 30s cycle test, respectively. Prior to muscle damage, subjects were significantly less fatigable (P < 0.05) at 40° (b = -2.39 ± 0.26) versus 80° (b = -5.50 ± 0.72). After muscle damage, subjects became significantly less fatigable at both 40° and 80° with recovery taking three days at 401 and seven days at 80°. Before damaging exercise, a greater rate of fatigue was observed under dynamic (b = -12.75 ± 2.3) versus isometric (80°) conditions (b = -5.50 ± 0.72). Isometric and dynamic fatigue 4 followed a similar temporal pattern after damaging exercise. When the effects of muscle damage on strength at 801 and maximal power output were compared, differences in the extent of performance loss and the time course of recovery were observed. At 1 hour post-exercise, strength was affected to a greater extent (30% reduction) than power (13% reduction) and whereas strength followed a linear recovery pattern, power suffered further decrements at day 1 (18%) and day 2 (16%) before starting to recover. The results indicate that under conditions of voluntary activation muscle becomes weaker but less fatigable under isometric and dynamic conditions following exercise-induced muscle damage. The lower starting torque / power output and the slower rate of decline in torque / power output observed in post-damage fatigue curves may be a phenomenon of selective type II fibre damage. Evidence suggests that type II fibres are selectively damaged during eccentric exercise and therefore post-damage fatigue curves may be missing their contribution to performance. The different recovery patterns observed for isometric and dynamic performance may indicate an inability to maintain central motor drive during complex dynamic tasks when damage is present.

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8

Kim, Jeong-Su. "The relationship of growth factor and muscle soreness to muscle hypertrophy". Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1101585.

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The purpose of the present study was to examine the relationship between exercise induced muscle damage and growth factors during two different modes of exercise. Nine healthy untrained male subjects participated in this study and performed two separate single bouts of isokinetic concentric (Con) and eccentric (Ecc) leg extension exercise on the CYBEX NORMT°". The workload was maintained at 75% of 1 RM for each trial, respectively. The maximum sets of 10 repetitions were performed during the Con trial, and the number was also duplicated during the Ecc trial, with 40 seconds of rest between sets. Serum levels of hGH, creatine kinase (CK), and lactic acid were measured, and the CK level was used to determine the degree of muscle tissue damage. A muscle soreness questionnaire was provided to the subjects to assess the degree of quadriceps muscle soreness following each trial. The EMG activity of the rectus femoris and vastus medialis muscles was recorded during each trial. The results of the present study demonstrated no significant differences in hGH output and CK activity between the exercise trials, although there was a significant different lactic acid response (P < 0.05). However, the Con trial produced significant increases (P < 0.05) in hGH and CK levels above the resting value at the post-exercise times. In fact, the 75% Con trial conducted in this study induced an increase in hGH release (peak: 8.23 ± 3.21 ng/ml) that was 2 X higher than a 120% Ecc trial (peak: 3.8 ± 1.2 ng/mI) of the prior study. The results of the present study demonstrate that a single bout of Con resistance exercise at the same intensity (75% of 1 RM), angular velocity, and ROM as a single bout of Ecc exercise can produce greater increases in hGH output and CK response than its Ecc counterpart. This finding does not support the previous results from this laboratory, showing that Ecc exercise is a stronger promoter of hGH output. However, it suggests that the amount of work performed is an important factor for hGH release because the exercise volume applied in the present study was greater than that of the prior study. The CK response of the subjects in this study, as well as the previous work indicate that hGH output is also dependent on exercise that elicits muscle damage. Therefore, the results of the present study suggest that the mode of exercise, Con vs. Ecc, is not as important as the stress placed on the exercising muscle in order to induce optimal muscle hypertrophy.
School of Physical Education

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9

Sundén, Jakob. "Associations between dolphin kick performance and lower extremity muscle strength, abdominal muscle strength and foot length in active competitive swimmers". Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-42351.

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Background: Maximal muscle strength and body proportions are some of the key attributes to be a fast swimmer. Even though dolphin kick (DK) has become essential to be a fast swimmer little is known of its associations to muscle strength and body proportions. Moreover, the effect of feet size has been stated to be a primary contributor to dolphin kick thrust production, but scientific evidence is still scarce. Aim: The aim of this study was to examine the correlation between lower extremity muscle strength, abdominal strength and feet length with dolphin kick performance over 15 meters in active competitive swimmers 15-20 years old Method: Twelve Test subjects (six male and six female) participated. Test subjects performed four 15 meters dolphin kick trials. Lower extremity muscle strength was tested with a three repetition maximum strength test and abdominal strength with brutal bench test. The muscles tested were rectus femoris, biceps femoris and rectus abdominis. Feet length was measured with a measuring tape. The correlations between lower extremity strength, abdominal strength and feet length with dolphin kick performance were calculated with spearman’s correlation. Results: Twelve test subjects between ages 15-20 years old participated. Spearman correlation test showed that lower extremity strength (rectus femoris: rs=-0.57 and biceps femoris: rs=-0.66) had a large association with dolphin kick performance. Abdominal strength (rs=-0.46) and feet length (rs=-0.35) had a moderate association with dolphin kick performance. Conclusion: The present study conclude that lower extremity strength is important for DK performance over 15 meters and that abdominal strength and feet length also is important but is less associated to it. The finding from this study can be used for making training programs for improving DK performance and for scouting swimmers with beneficial traits for specific swimming technique.

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10

Trezise, Joanne C. "Relative importance and plasticity of anatomical and neuromuscular factors affecting joint torque production". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2014. https://ro.ecu.edu.au/theses/1407.

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The present research aimed to determine (i) the relative influence anatomical and neuromuscular variables on maximal isometric, concentric and eccentric knee extensor torque (Study 1); (ii) whether the change in strength following a 10-week strength training program is associated with changes in specific anatomical and neuromuscular variables (Study 2a); (iii) whether anatomical and neuromuscular adaptations are dependent on their pre-training magnitudes; and (iv) whether it is possible to ‘predict’ an individual’s adaptation to strength training based on their anatomical and neuromuscular pre-training magnitudes (Study 2b). The variables assessed throughout the studies include muscle cross-sectional area (CSA), fascicle length and angle from the proximal, middle and distal regions of the four quadriceps components; agonist (EMG:Mwave) and antagonist (EMG normalised to MVC) muscle activity, percent voluntary activation (%VA; interpolated twitch technique); maximum isometric and slow speed concentric and eccentric (60°/s), unpotentiated and potentiated twitch torques; and patella tendon moment arm distance. Using a cross-sectional (observational) study design (Study 1; n = 56) models incorporating CSA, fascicle angle and muscle activity and activation were found to best predict both maximum isometric and eccentric torque (R2 = 0.72 and 0.62). Maximum concentric torque was best predicted by a model incorporating CSA, fascicle angle and moment arm (R2 = 0.64) making it suitable for predicting maximal torque in clinical/rehabilitation populations. Proximal CSA was included in the strongest models rather than the traditionally used mid-muscle CSA, indicating its potential functional importance. The strong predictive ability of models incorporating both CSA and fascicle angle indicate that the quantity of contractile tissue strongly influences inter-individual differences in strength expression. Following 10 weeks of heavy lower-limb heavy strength training (Study 2a; n = 36), the change in isometric torque was best (although weakly; R2 = 0.27) predicted by models incorporating the change in proximal-region vastus lateralis CSA and fascicle angle, and changes in concentric and eccentric torque were best predicted by average quadriceps muscle activity, proximal-region CSA (either vastus lateralis or whole quadriceps) and vastus intermedius fascicle angle (R2 = 0.40 and 0.41). Changes in fascicle angle were weakly correlated with the change in strength despite its inclusion in the strongest models, highlighting the requirement to examine interactions between variables when assessing their influence on strength change. Furthermore, the weak relationships observed between the change in strength and the change in neuromuscular variables (Study 2a) indicate that the assumption that simultaneous changes observed in strength, anatomical structure and neuromuscular function following training indicate potential causal association may need to be reconsidered. While muscle activation measured pre-training during isometric contractions was moderately and negatively correlated with the strength change following training (Study 2b), there was no correlation for proximal-region CSA. This indicated limited scope for improvement in activation isometrically in individuals with greater levels of activation prior to training, but that all individuals had similar scope for hypertrophy. It was not possible to predict the strength change elicited by training from the measurements obtained before training (R2 = 0.06 to 0.27). A comparative data set presented in Study 1 provides clinicians with a tool to evaluate an individual’s maximum torque capacity, anatomical structure and neuromuscular function. While accurate prediction of strength change following training cannot be made based on pre-training testing using the current protocols (Study 2b), strength training programs targeted to improve muscle activation (Study 2a) might elicit the greatest improvements in concentric and eccentric knee extensor strength.

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11

Al, Hamdani A. "The measurement of muscle strength in allergic response". Thesis, University of Salford, 1990. http://usir.salford.ac.uk/14798/.

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The purpose of this thesis was to show a relationship between muscle strength and allergic reactions. Clinics have for many years relied on what have become traditional methods for testing for allergic reactions. These include such tests as the Patch test and the Skin-Prick test. Both these tests cause discomfort and irritation to sensitive patients. The historical development of allergies is outlined, showing that scientists and clinicians in the late 18th and early 19th century were aware of certain reactions which people showed to apparently normal non-reactive foods. The development of methods of diagnosing allergies such as the elimination diet, which dates back to approx 1940, are surveyed. Current practices are also studied with the use of photographs. The reaction of the skin to modern day testing practices is shown. In some cases these reactions are quite violent. The Applied Kinesiology Test is examined as a universally used test which when carried out by an experienced Kinesiologist can give a true but highly subjective response to a patients allergic condition. A system has been developed based on the relationship between muscle strength and allergies, the components of this system were readily available at little cost. Once a basic system was built it was possible to perform trials on patients at an established allergy clinic. With the aid of a data printer it became possible to prove first graphically and second statistically that there was a statistically valid relationship between the measured muscle strength and allergies. The conclusion shows that the final version of the operating system is capable of equaling the performance of an experienced Kinesiologist, showing its results both digitally and graphically rather than subjectively. The various deductions and recommendations which are detailed, point towards a readily marketable device which could represent a potential break through in modern allergy testing. The system will also open the way for clinicians to make an objective assessment of the relationship between muscle strength and allergic sensitivity via further research.

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12

Rodgers, Justin Fraser. "Classification and projection strength of muscle spindle afferents". Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309421.

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13

Siekemeyer, Leah C. "Inspiratory Muscle Strength Training in Upper Airway Obstruction". Miami University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=miami1306417918.

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14

O'Hagen, Sean F. "The self-control "muscle" : can training increase strength? /". Diss., Online access via UMI:, 2008.

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15

Stephensen, David. "Influence of muscle morphology on muscle strength and gait in children with haemophilia". Thesis, University of East London, 2010. http://roar.uel.ac.uk/2630/.

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Improvements in medical treatment mean that although joint haemorrhages still occur and radiological signs of joint damage continue to be found in young boys with haemophilia, they present with no apparent clinical signs of joint damage. Evaluating muscle strength with an isokinetic device, muscle morphology with ultrasound imaging and gait patterns with 3-D motion capture, the primary aim of this study was to investigate whether muscle strength, morphology and gait characteristics of children with haemophilia differed from those of typically developing children. No joint or muscle impairment was detected with the Colorado Physical Examination in twenty-six boys with haemophilia, aged 6-12 years and a history of ankle joint haemarthrosis. But compared to a group of twenty-six age and size-matched typically developing boys, those with haemophilia showed deficits in isokinetic muscle strength of the knee extensors, ankle dorsi and plantarflexors (p<0.05), together with reduced size of vastus lateralis and lateral gastrocnemius muscles (p<0.05). Adaptations in walking were also found (p<0.05); greater knee flexion and ankle dorsiflexion angles, vertical ground reaction forces, knee flexion moments, ankle external rotation moments and EMG activity of lateral gastrocnemius. Regression analysis identified key relationships linking reduced lower limb muscle strength, altered muscle morphology and biomechamcal adaptations of walking patterns in boys with haemophilia (p<0.05). Implications from this study suggest that lower limb joint and muscle function in young boys with haemophilia and a history of ankle joint bleeding differed from that of their typically developing peers and were more impaired than current clinical evaluations imply.

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16

Wheeler, Amanda A. "Handgrip strenth [sic] variations in baseball and softball over a six-week period of no strength training". Huntington, WV : [Marshall University Libraries], 2006. http://www.marshall.edu/etd/descript.asp?ref=699.

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Theses (M.S.)--Marshall University, 2006.
Title from document title page. Includes abstract. Document formatted into pages: contains viii, 37 pages. Includes curriculum vitae. Bibliography: p. 16-18.

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17

Wu, Cheng Kam-chee Polina. "The effect of mental training in delaying muscle fatigue /". Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk:8888/cgi-bin/hkuto%5Ftoc%5Fpdf?B23294991.

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18

Tanaka, Hirofumi. "Dry-land strength training for competitive swimming : interaction between strength training and swim training". Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834620.

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In an attempt to determine the value of dry-land weight training on swimming performance, two groups of twenty four intercollegiate male swimmers were equated based upon pre-swimming performance, swim power values, stroke specialities, and collegiate swimming experience. At the start of a swimming season there were no significant differences (p>0.05) between the swim training group (SWIM, N=12) and the combined weight and swim training group (COMBO, N=12). Throughout the 13 weeks of their competitive swimming season, both SWIM and COMBO swam together six days a week. In addition, the COMBO engaged in a weight training program three days a week between the third and eleventh weeks (for eight weeks) of the season. The weight training program, using free weights, was intended to simulate arm actions and muscle actions similar to those used during front crawl swimming. Both COMBO and SWIM groups had significant but similar power gains (p<0.05) as measured on the biokinetic swim bench and during a tethered swim. Swimmers in both groups experienced a significant (p<0.05) increase in competitive swim performance from 1991 to 1992 (0.89 ± 0.60% in COMBO and 0.87 ± 0.4Q% in SWIM) whereas no change in distance per stroke (p>0.05) was observed throughout the course of this investigation. Mean total testosterone levels were not altered during the weight training period in either group. No significant (p>0.05) differences were found between the groups in any of the swim power and swimming performance tests. In this investigation, dry-land weight training did not improve swimming performance despite the fact that the COMBO was able to increase the weights used during strength training by 25 to 35%. The lack of positive transfer between dry-land strength gains and swimming propulsive force may be due to the specificity of training.
Human Performance Laboratory

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19

Sonnekalb, Sara. "Impact of different warm-up conditions on hamstring torque and power". Connect to this title online, 2005. http://www.oregonpdf.org.

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Thesis (M. Ed.)--Bowling Green State University, 2005.
Includes bibliographical references (leaves 38-44). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

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20

Penailillo, Luis. "Muscle damage and metabolic profiles of eccentric cycling". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/706.

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Abstract (sommario):

Eccentric cycling, in which the knee extensor muscles perform eccentric contractions while trying to brake the backward rotational movements of the cranks of a cycle ergometer, has been shown to effectively increase muscle function and volume with a low metabolic cost. However, acute responses to repeated eccentric cycling bouts have not been well documented. Thus, the primary purposes of this PhD project were to investigate muscle damage and metabolic profiles of eccentric cycling in comparison to concentric cycling (Studies 1-3), and muscle-tendon behaviour (Study 4) during eccentric cycling in relation to muscle damage. Study 1 compared muscle damage and metabolic profiles between a bout of concentric cycling (CONC) and two bouts of eccentric cycling (ECC1, ECC2) performed by 10 healthy men (28 ± 8 y), with a 2-wk interval between bouts. All cycling bouts were performed for 30 min at 60% of CONC maximal power output (POmax). Heart rate (HR), oxygen consumption, blood lactate (BLa) and rate of perceived exertion were 19-65% lower during ECC1 than CONC, and HR and BLa were 12-35% lower during ECC2 than ECC1. Exercise-induced decreases in knee extensor maximal voluntary contraction (MVC) torque and vertical jump height as well as increases in muscle soreness were significantly greater after ECC1 than CONC and ECC2, and no significant changes in these variables were found one day after CONC and ECC2. It was concluded that eccentric cycling was less metabolically demanding than CONC, and muscle damage was minimal after the second eccentric cycling bout. Study 2 examined fat and carbohydrate utilisation during and immediately after cycling, and resting energy expenditure before and both 2 and 4 days post-cycling using indirect calorimetry. An oral glucose tolerance test was performed before, and 1 and 3 days post-cycling. Fat utilisation was greater during ECC1 (72%) and ECC2 (85%) than CONC, and was 48% greater during ECC2 than ECC1. Post-exercise energy expenditure and fat utilisation were less after ECC1 than CONC (30% and 52%, respectively), but similar between CONC and ECC2. Glucose uptake increased 3 days post-ECC1. These results suggest greater fat utilisation during and after eccentric than concentric cycling without glucose uptake impairment. Study 3 tested the hypothesis that rate of force development (RFD) would be a more sensitive marker of muscle damage than MVC torque by comparing the changes in MVC torque and RFD after CONC, ECC1 and ECC2. Decreases in MVC torque were significantly greater immediately and 1-2 days after ECC1 than CONC and ECC2. RFD decreased immediately after all cycling bouts, but RFD measured in the interval 100-200 ms (RFD100-200) decreased at all time points after ECC1 (24-32%) as well as immediately after ECC2 (23%), but did not change after CONC. The magnitude of decrease in RFD100-200 after ECC1 was 7-19% greater than MVC torque. These suggest that RFD100-200 is a more specific and sensitive marker of eccentric exercise-induced muscle damage than MVC torque. To investigate the mechanisms underpinning the repeated bout effect in eccentric cycling, Study 4 examined the hypothesis that vastus lateralis muscle-tendon behaviour would be different between two (i.e. repeated) eccentric cycling bouts. Eleven healthy men (27.1 ± 7.0 y) performed 10 min of eccentric cycling at 65% of CONC POmax twice (ECC1, ECC2) separated by 2 weeks. Greater muscle soreness was developed 1-2 days after ECC1 than ECC2. Electromyogram and crank torque were similar between bouts, but the magnitude of fascicle elongation during ECC2 was 16% smaller than ECC1. These results suggest that smaller elongation of fascicles was associated with less muscle soreness after ECC2, and possibly the repeated bout effect. These studies revealed the muscle damage profile of eccentric cycling, one of the potential mechanisms of the repeated bout effect, and metabolic characteristics of repeated eccentric cycling bouts. Since muscle damage is minimal and can be abolished by proper prescription, eccentric cycling may be an ideal exercise for elderly and frail individuals with impaired muscle oxidative function (e.g. diabetes and chronic obstructive pulmonary disease). Further studies are warranted in these populations.

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De, Ste Crox Mark Brian Amos. "The development of isokinetic leg strength". Thesis, University of Exeter, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244971.

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22

Olivier, Pierre Emile. "Isokinetic force profile of the cervical spine in a healthy adult urban South African population". Thesis, Nelson Mandela Metropolitan University, 2008. http://hdl.handle.net/10948/982.

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Abstract (sommario):

The aim of this study was to establish reference data for the cervical spine’s dynamic force characteristics in a healthy adult urban South African population aged 19 to 69 years. The reference data was classified according to gender discriminate age categories. In total ten gender discriminate age categories, five male and five female, were created; 19 to 29, 30 to 39, 40 to 49, 50 to 59 and 60 to 69-year-olds. The force characteristics measured, analysed and used to generate reference data in stanine format were: absolute peak torque (P-), relative peak torque (P-/BW), peak power (Pow-), relative peak power (Pow-/BW), peak work (W-), relative peak work (W-/BW), torque acceleration energy (TAE-), maximal voluntary cervical muscle contraction range of motion (MVCR-), controlled full range of joint motion (CFR-), joint angle at peak torque (Jang@P-) and peak torque ratios for cervical flexion (-F), extension (-E), lateral flexion to the dominant (-LD) and non-dominant (-LN) sides. In addition biographic and anthropometric data was also collected. Data, grouped in the ten gender discriminate age categories were compared and statistically and practically significant differences were highlighted between the gender discriminate age categories. Inferential statistics used included ANOVA and Cohen’s d. A significance level of α = .05 was used in all inferential statistical analyses. Correlations between various anthropometric and isokinetic strength variables were also explored.

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23

Gee, Thomas. "Recovery of muscle function following strength training in rowers". Thesis, Northumbria University, 2012. http://nrl.northumbria.ac.uk/8099/.

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Abstract (sommario):

Strength training using free weights is performed by athletes in many sports as a means of enhancing performance. However, there is a dearth of research investigating the acute impact of bouts of this form of strength training on muscle function, which closely mimics the athletes’ sport or event. High forces are produced during a rowing race and subsequently strength training forms an integral part of the overall training programme for rowers. However, there is little documented evidence regarding the strength and conditioning practices occurring in rowing. Therefore the aims of this thesis were to investigate and draw conclusions regarding the strength and conditioning practices occurring within British rowing and to evaluate the impact of typical bouts of strength training on muscle function in rowers. To investigate the strength and conditioning practices within British rowing a questionnaire was completed by 32 coaches and semi-structured interviews were undertaken with two coaches of elite rowers (study 1). Information from both sources indicated that rowers performed two to three strength training sessions per week, involving Olympic lifting and multi-joint free weight strength exercises, performed across multiple sets with low to moderate repetition ranges. Physical testing most commonly involved assessment of cardiovascular endurance, muscular power and strength. Twenty four hours of recovery were generally afforded between strength training and intensive rowing training while longer periods were permitted before rowing races (> 48 h). Prior to the intervention studies, the reproducibility of subsequently assessed measures was assessed using trained rowers (study 2). Typical error (%) was low for 2000 m mean power (2.4 %), and low to moderate for the assessments of strength and power (3.0-5.9 %). Measures of peak blood lactate (11.5 %), creatine kinase (21.0 %) and surface electromyography (11.1-44.8 %, across various sites) demonstrated greater variability similar to previous studies. For studies 3 and 4, trained rowers performed 250 m and 2000 m rowing tests respectively, alongside various measures of muscle function before and after an acute bout of free weight multi-joint strength training (ST). For both studies, increases in perceived muscle soreness and CK indicated that muscle damage was present after ST for 24-48 h. Maximal power generating ability was decreased in both studies as evidenced by decrements in the 250 m test, power strokes, and jump height. However, in study 4, 2000 m rowing time was unaffected, leading to the conclusion that the specific muscle function required for the power tests was affected through damage to type II muscle fibres. Findings from study 1 indicated that rowers commonly perform strength training three times per week; therefore study 5 investigated the impact of this weekly frequency of strength training on muscle function. Twenty four hours after three bouts of ST within a five day period, trained rowers experienced significant decreases in maximal voluntary contraction, jump height and power stroke tests as well as increases in CK and soreness; however as with study 4, 2000m performance was unaffected. Trends for decreases in peak lactate and anaerobic energy liberation (p < 0.10, Effect Size = 0.40-0.56) were present alongside significant increases in EMG at three sites during the post-ST 2000 m test. These findings suggest a decreased utilisation of the anaerobic capacity coupled with increased central motor drive suggesting a change in muscular recruitment patterns during the follow up 2000 m rowing test. It would appear that following extensive strength training, physiological processes were adapted during subsequent rowing exercise, to compensate for the loss in higher threshold muscle fibre function, in order to affect the same level of rowing performance achieved in the rested state. These findings might suggest that participants operated within a physiological reserve and/or that multiple-exercise-regulation-algorithms exist with which a similar exercise performance can be achieved.

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McMahon, Callie Griggs. "Muscle Strength and Body Cell Mass in Postmenopausal Women". Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/42296.

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It has been observed that the normal process of aging is associated with a decline in muscle strength and mass. It has also been observed that total body potassium and intracellular water (ICW) decrease with age, reflecting a loss of body cell mass (BCM), 60% of which is the skeletal muscle. It is generally accepted that traditional high-intensity strength training (ST) regimens can not only attenuate, but in some cases, reverse some of these aging-related changes. Periodization, a nontraditional approach to strength training, has been demonstrated to stimulate more rapid increases in muscle strength than traditional approaches in young adults; however, it has not been comprehensively evaluated in postmenopausal women. Investigators have consistently reported an increase in muscle strength in older adults undergoing both short- and long-term traditional ST programs. It is fairly well accepted that early increases in muscle strength are attributable to neurologic adaptations. There has been less consistency in the literature regarding the timing and nature of changes in muscle quality and mass with ST. Although several investigators have reported increased muscle protein synthesis rates as early as 2 weeks after ST initiation in older adults, the majority of published reports support the notion that significant NET gains in intracellular protein, and thus, gains in muscle mass/volume/hypertrophy do not occur before 9-10 weeks. Changes in intracellular water, which would be expected to occur with changes in intracellular protein, have not been studied during short-term ST interventions in older adults. Bioimpedance spectroscopy (BIS) has been validated as a field technique to accurately measure ICW (and BCM) changes in HIV infected individuals. The primary aim of the current study was to determine if muscle strength would increase in postmenopausal women undergoing a novel (periodized) ST intervention of 10 weeks duration. A secondary aim was to determine if BIS would detect a change in ICW in the study subjects from baseline to study conclusion. Study participants were eleven, healthy postmenopausal women between the ages of 60 and 74 (mean age: 65 Â± 4.4 y) who had not engaged in ST in the six months preceding the study. ICW and muscle strength were assessed at baseline and at study conclusion. The ST program was conducted twice a week for 10 weeks at the Senior Center in Blacksburg, VA. Participants performed seven different exercises incorporating upper body and lower body muscle groups. The women performed one set of 8-12 repetitions at an intensity of 80% of one repetition maximum (1 RM) the first week, progressing to 2 sets of 8-12 repetitions at the same intensity during the second week. The remaining weeks consisted of three sets of 8-12 repetitions, performed at an intensity of 80%, 75%, and 70% of their current 1 RM, respectively. One RM was reassessed every other week. The major result from this study was that muscle strength of all trained muscle groups increased in postmenopausal women undergoing 10 weeks of pyramid ST (P<0.05). In addition, the pyramid ST protocol utilized in this study was well-tolerated and resulted in no injuries in any of the older women in the study, indicating that this approach may be used safely in this population. Mean ICW measured by the field method BIS did not change over the course of the study. This result was consistent with other published data reporting no changes in lean body mass or muscle volume/area by more sophisticated techniques.
Master of Science

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25

Massey, Garry J. "Muscle-tendon unit morphology, architecture and stiffness in relation to strength and responses to strength training". Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/24712.

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This thesis examined the change in skeletal muscle architecture with contractile force production, the relationship of architecture with muscle strength parameters and if muscle tendinous tissue stiffness determines in vivo explosive strength (i.e. rate of torque development, RTD). Muscle and tendinous tissue adaptations to contrasting strength training regimes, and the potential capacity of these tissues to adapt following chronic strength training were also explored. Quadriceps femoris fascicle length (FL) decreased, while the pennation angle (PA) increased in a curvi-linearly manner from rest to maximal voluntary contraction (MVC) torque. Consequently, effective physiological cross-sectional area (effPCSA) during MVC was 27% greater than at rest, although effPCSA measured at rest and during MVC had similar correlations to maximal strength. In the earliest phase of contraction, FL, but not PA, was negatively related (R2=0.187) to voluntary RTD. Neither FL nor PA was related to maximal isometric or dynamic strength. Muscle-tendon unit (MTU) and patellar tendon (PT) stiffness were unrelated to voluntary and evoked RTD. Relative PT stiffness was also unrelated to relative RTD, although relative MTU stiffness was related to voluntary RTD (25-55%MVT, R2≤0.188) and evoked RTD (5-50%MVT, R2≤0.194). MTU stiffness increased after sustained-contraction (SCT, +21%), though not explosive-contraction strength training (ECT). PT stiffness increased similarly after ECT (+20%) and SCT (+16%), yet neither induced tendon hypertrophy. SCT produced modest muscle (+8%) and aponeurosis (+7%) hypertrophy. Chronic strength trained (CST: >3 years) males had substantially greater muscle and aponeurosis size, but similar tendon size as untrained controls (UNT) and short-term (12 weeks) strength trained (STT) individuals. Between these groups, at the highest common force, MTU stiffness was indifferent, while PT stiffness was similarly greater in STT and CST than UNT. These results suggest FL and PA have little influence on muscle strength and tendon stiffness has no influence on RTD. Maximum strength negated any qualitative influence of MTU stiffness on in vivo RTD. Component MTU tissues (muscle-aponeurosis vs. external tendon) adapt differentially depending on the strength training regime. Specifically, free tendon appeared to adapt to high magnitude loading, while loading duration is also an important stimulus for the muscle-aponeurosis. However, chronic strength training was not concordant with greater higher force MTU stiffness, and does not further increase higher force PT stiffness beyond the adaptations that occur after 12 weeks of strength training. Finally, no evidence was found for tendon hypertrophy in response to strength training.

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26

Hoessly, Margaret. "The effect of concentric and eccentric muscle action on muscle stiffness at the knee in subjects with spasticity of the quadriceps dissertation submission to Auckland University of Technology for the degree of Master of Health Science, January, 2003". Full thesis. Abstract, 2003. http://puka2.aut.ac.nz/ait/theses/HoesslyM.pdf.

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27

Balshaw, Thomas G. "Acute neuromuscular, kinetic, and kinematic responses to accentuated eccentric load resistance exercise". Thesis, University of Stirling, 2013. http://hdl.handle.net/1893/17174.

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Abstract (sommario):

Neurological and morphological adaptations are responsible for the increases in strength that occur following the completion of resistance exercise training interventions. There are a number of benefits that can occur as a result of completing resistance exercise training interventions, these include: (i) reduced risk of developing metabolic health issues; (ii) decreased risk and incidence of falling; (iii) improved cardiovascular health; (iv) elevated mobility; (v) enhanced athletic performance; and (vi) injury prevention. Traditional resistance exercise (constant load resistance exercise (CL)) involves equally loaded eccentric and concentric phases, performed in an alternating manner. However, eccentric muscle actions have unique physiological characteristics, namely greater force production capacity and lower energy requirements, compared to concentric actions. These characteristics have led to the exploration of eccentric-focused resistance exercise for the purposes of injury prevention, rehabilitation, and enhancement of functional capacity. Accentuated eccentric load resistance exercise (AEL) is one form of eccentric-focused resistance exercise. This type of resistance exercise involves a heavier absolute external eccentric phase load than during the subsequent concentric portion of a repetition. Existing training study interventions comparing AEL to CL have demonstrated enhancements in concentric, eccentric, and isometric strength with AEL. However, no differences in strength adaptations have been reported in other AEL vs. CL training studies. Only 7 d intensified AEL training interventions have measured neuromuscular variables, providing evidence that enhanced neuromuscular adaptations may occur when AEL is compared to CL. Therefore, a lack of information is currently available regarding how AEL may differentially affect neuromuscular control when compared to CL. Furthermore, the equivocal findings regarding the efficacy of AEL make it difficult for exercise professionals to decide if they should employ AEL with their athletes or patients and during which training phase this type of resistance exercise could be implemented. Therefore, the aims of this thesis were: (i) to examine differences in acute neuromuscular, kinetic, and kinematic responses between AEL and CL during both lower-body single-joint resistance exercise and multiple-joint free weight resistance exercise; (ii) to assess acute force production and contractile characteristics following AEL and CL conditions; (iii) to investigate the influence of eccentric phase velocity (and time under tension) on acute force production and contractile characteristics following AEL and CL conditions; and (iv) to compare common drive and motor unit firing rate responses after single- and multiple-joint AEL and CL. Before investigating neuromuscular, kinetic, and kinematic responses to AEL it was deemed necessary to evaluate normalisation methods for a multiple-joint free weight resistance exercise that would permit the implementation of AEL. Therefore, the aim of the first study of the thesis was to evaluate voluntary maximal (dynamometer- and isometric squat-based) isometric and submaximal dynamic (60%, 70%, and 80% of three repetition maximum) electromyography (EMG) normalisation methods for the back squat resistance exercise. The absolute reliability (limits of agreement and coefficient of variation), relative reliability (intraclass correlation coefficient), and sensitivity of each method was assessed. Strength-trained males completed four testing sessions on separate days, the final three test days were used to evaluate the different normalisation methods. Overall, dynamic normalisation methods demonstrated better absolute reliability and sensitivity for reporting vastus lateralis and biceps femoris EMG compared to maximal isometric methods. Following the methodological study conducted in Chapter 2, the next study began to address the main aims of the thesis. The purpose of the third chapter of the thesis was to compare acute neuromuscular, kinetic, and kinematic responses between single-joint AEL and CL knee extension efforts that included two different eccentric phase velocities. Ten males who were completing recreational resistance exercise attended four experimental test day sessions where knee extension repetitions (AEL or CL) were performed at two different eccentric phase velocities (2 or 4 s). Elevated vastus lateralis eccentric neuromuscular activation was observed in both AEL conditions (p= 0.004, f= 5.73). No differences between conditions were detected for concentric neuromuscular or concentric kinematic variables during knee extension efforts. Similarly, no differences in after-intervention rate of torque development or contractile charactersitics were observed between conditions. To extend the findings of the third chapter of the thesis and provide mechanistic information regarding how AEL may differentially effect acute neuromuscular variables that have been reported to be undergo chronic adaptations, additional measures that were taken before and after the intervention described in the previous chapter were analysed. Therefore, the purpose of the fourth chapter of the thesis was to compare motor unit firing rate and common drive responses following single-joint AEL and CL knee extension efforts during a submaximal isometric knee extension trapezoid force trace effort. In addition, motor unit firing rate reliability during the before-intervention trapezoid force trace efforts was assessed. No differences in the maximum number of detected motor units were observed between conditions. A condition-time-point interaction effect (p= 0.025, f= 3.65) for firing rate in later-recruited motor units occurred, with a decrease in firing rate observed in after-intervention measures in the AEL condition that was completed with a shorter duration eccentric phase. However, no differences in common drive were detected from before- to after-intervention measures in any of the conditions. The time period toward the end of the plateau phase of before-intervention trapezoid force trace efforts displayed the greatest absolute and relative reliability and was therefore used for motor unit firing rate and common drive analysis. The purpose of the fifth chapter was to compare acute neuromuscular and kinetic responses between multiple-joint AEL and CL back squats. Strength-trained males completed two experimental test day sessions where back squat repetitions (AEL or CL) were performed. Neuromuscular and kinetic responses were measured during each condition. No differences in concentric neuromuscular or concentric kinetic variables during back squat repetitions were detected between conditions. Elevated eccentric phase neuromuscular activation was observed during the AEL compared to the CL condition in two to three of the four sets performed for the following lower-body muscles: (i) vastus lateralis (p< 0.001, f= 15.58); (ii) vastus medialis (p< 0.001, f= 10.77); (iii) biceps femoris (p= 0.003, f= 6.10); and (iv) gluteus maximus (p= 0.001, f= 7.98). There were no clear differences in terms of the neuromuscular activation contributions between muscles within AEL or CL conditions during eccentric or concentric muscle actions. Following the investigation of acute motor unit firing rate and common drive responses to lower limb single-joint AEL and CL in the fourth chapter of the thesis, the question arose as to whether or not similar responses would occur in a more complex model, such as a multiple-joint resistance exercise. Multiple-joint resistance exercise poses different neuromuscular activation, coordination, and stabilisation demands. Therefore, the purpose of the sixth chapter of the thesis was to compare acute motor unit firing rate and common drive responses following multiple-joint lower-body free weight AEL and CL.

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Lau, Wai-shing Vincent. "Comparison of power grip and lateral pinch strengths between the dominant and non-dominant hands for normal Chinese male subjects of different occupational demand". Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23339718.

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29

Magoffin, Ryan Darin. "The Effect of Whole Body Vibration on Exercise-Induced Muscle Damage and Delayed-Onset Muscle Soreness". BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6217.

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Abstract (sommario):

Current scientific evidence suggests that when whole body vibration (WBV) is used as a warm-up prior to performing eccentric exercise, delayed-onset muscle soreness (DOMS) is mitigated and strength loss recovers faster. These benefits were observed primarily in nonresistance-trained individuals. The aim of this study was to determine if WBV could mitigate soreness and expedite strength recovery for resistance-trained individuals when used as a warm-up prior to eccentric exercise. Thirty resistance-trained males completed 300 maximal eccentric contractions of the quadriceps after warming up with (WBV) or without (CON) WBV. Both CON and WBV experienced significant isometric (27.8% and 30.5%, respectively) and dynamic (52.2% and 47.1%, respectively) strength loss immediately postexercise. Isometric strength was significantly depressed after 24 hours in the CON group (9.36% p < 0.01), but not in the WBV group (5.8% p = 0.1). Isometric strength was significantly depressed after 48 hours in the CON group (7.18% p < 0.05), but not in the WBV group (4.02% p = 0.25). Dynamic strength was significantly decreased in both the CON and WBV groups both at 24 hours (19.1% p < 0.001, and 16.1% p < 0.001, respectively), 48 hours (18.5% p < 0.01, and 14.5% p < 0.03), and 1 week postexercise (9.3% p = 0.03, and 3.5%, respectively). Pain as measured by visual analog scale (VAS) was significant in both CON and WBV groups at 24 and 48 hours postexercise, but the WBV experienced significantly less soreness than the CON group after 24 hours (28 mm vs. 46 mm p < 0.01 respectively), and 48 hours (38 mm vs. 50 mm p < 0.01). Pain as measured by pain pressure threshold (PPT) increased significantly in both groups after 24 and 48 hours, but there was no difference in severity of perceived soreness. The use of WBV as a warm-up may mitigate DOMS but does not appear to expedite the recovery of strength in the days following eccentric exercise in resistance-trained individuals.

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Hurd, Wendy J. "Quadriceps strength and the ACL deficient non-coper". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 192 p, 2007. http://proquest.umi.com/pqdlink?did=1251900461&Fmt=7&clientId=79356&RQT=309&VName=PQD.

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31

Lau, Wai-shing Vincent, e 劉偉誠. "Comparison of power grip and lateral pinch strengths between the dominant and non-dominant hands for normal Chinese male subjects ofdifferent occupational demand". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31970138.

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32

Raue, Ulrika. "Effects of concentric vs eccentric resistance training on skeletal muscle adaptations in humans". Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1221284.

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Abstract (sommario):

The Beothuk Indians were an extinct group of Amerinds who were among the earliest founders of Newfoundland. In literature, the Beothuk were described as perhaps being phenotypically more similar to Europeans than Asians (Gatschet 1890, Lloyd 1875, 1876a, Marshall 1996). In this research, mitochondrial DNA (mtDNA) analysis was performed on a Beothuk individual in order to determine his haplotype and, perhaps, shed light on the origins of the Beothuk.For this analysis, a tooth of Nonosabasut, a Beothuk chief who died in 1819 was loaned from the Royal Museum of Scotland. Ancient DNA was extracted from 172 mg of dentin from the tooth. The DNA was cut with two blunt-end restriction enzymes, RsaI and HaeIII. Double-stranded DNA adapters were ligated to the blunt ends. A single adapter was used to amplify the resulting fragments using PCR. In this manner, two libraries of the DNA were created that could be readily reamplified using a small amount of the PCR product. mtDNA type was determined by amplifying specific regions and performing Restriction Fragment Length Polymorphism analysis and sequencing. It was determined that the Beothuk individual had a 9-bp deletion at nucleotide position (np) 8272, an Alul restriction site at np 5176, and heteroplasmy for a HincII restriction site at np 13,259, indicating that the Beothuk individual falls into the Native American Haplogroup B. Haplogroup B is not present in modern Siberian populations, whereas the remaining Native American mtDNA haplogroups are. It has been hypothesized that Haplogroup B arrived in the Americas at a different time than haplogroups A, C, D, and X, about 16,000-13,000 YBP (Years Before Present) (Starikovskaya et al. 1998). Haplogroup B can be found in some modern Taiwanese, Japanese, Korean, Evenk, and other Asian populations.Sequencing of the D-Loop region revealed a G to A transition at np 16303. To our knowledge, this transition was never previously reported in a Native American. This transition has been reported in Tibetans, Koreans, Hans, and Japanese, all considered to be southeast Asian Causacoids (Torroni et al. 1993b, 1994b). This transition, also frequently described in the Caucasian Haplogroup H, is especially prevalent in Spain and among the Basque. It is described as a root haplotype of Haplogroup H whose expansion was estimated to be between 12,300-13,200 YBP (Torroni et al. 1998). This time estimate coincides with the expansion of Haplogroup B. One possible explanation for this transition may be some admixture of the Beothuk with a Caucasian population.
School of Physical Education

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33

Kostek, Matt. "Insulin-like growth factor 1 genotype influences muscle strength response to strength training in older adults". College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1974.

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Abstract (sommario):

Thesis (Ph. D.) -- University of Maryland, College Park, 2004.
Thesis research directed by: Kinesiology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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34

Moriello, Carolina. "Relation of muscle strength to functional walking capacity post stroke". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97973.

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The main objective of this observational, cross sectional study is to estimate the extent to which muscle strength is independently associated with functional walking capacity among stroke patients. Sixty three stroke patients, from 3 to 12 months post onset, were evaluated on functional walking capacity (6 Minute Walk Test), muscle strength (hand held dynamometry), balance (Berg Balance Scale), and tone (Modified Ashworth Scale and Composite Spasticity Index). The results showed that a global index of muscle strength, balance, tone and comorbids explain 70% of the variability of the 6MWT. Moreover, the muscle strength of the affected side in gravity related positions, as an index, explain most of the variability (37%), in comparison to the other positions. In addition, the hip flexor in an alternate against gravity position, as an individual muscle, explains the most variability of walking capacity.

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Hughes, Philip Daniel. "Development and clinical application of tests of respiratory muscle strength". Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391625.

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36

Williams, Alun Gwyn. "Studies of muscle strength : with special reference to military training". Thesis, University of Birmingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369339.

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Abstract (sommario):

Initially, this research programme investigated training methods to improve strengthrelated material handling performance in the British Army. A widely used training programme was evaluated for its effectiveness in improving material handling, and found to provide some significant but small improvements. Modifications to the training programme, including the use of a large strength-training element, were devised based on prior research evidence. The modified training programme was evaluated and compared with the original programme, and shown to be significantly more effective at improving material handling. Any means to improve the effectiveness of strength training per se would further improve the effectiveness of the modified training programme. Consequently, a potential means to improve the effectiveness of strength training via postexercise nutritional supplementation was investigated. The encouraging but not statistically significant results suggested further research to evaluate the potential of the supplementation regimen and also to better illuminate the possible mechanisms. An evaluation of the hormonal and metabolic responses to varying combinations of resistance exercise and supplementation provided little additional evidence to support the effectiveness of the supplementation regimen. However, the likely mechanism of the effect that may exist was better identified as a direct effect of insulin or amino acid availability on muscle cell growth, rather than a reduction in circulating cortisol concentration.

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Ngambi, Onambele Gladys Leopoldine. "Muscle strength control in women : oestrogen, ACE and training effects". Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271429.

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38

Parker, Dawn Fiona. "Factors controlling the development and strength of human skeletal muscle". Thesis, University College London (University of London), 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244016.

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39

Park, Changmin. "Inter-limb Differences in Quadriceps Strength and Voluntary Muscle Activation". University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1292855316.

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40

Ray, Christin. "Effects of Respiratory Muscle Strength Training in Classically Trained Singers". The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1405505205.

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41

Mills, Matthew. "Changes in muscle function and performance with age". Thesis, University College London (University of London), 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310522.

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42

Buckthorpe, Matthew. "Neural contributions to maximal muscle performance". Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/14772.

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Abstract (sommario):

Neural activation is thought to be essential for the expression of maximal muscle performance, but the exact contribution of neural mechanisms such as the level of agonist, antagonist and stabiliser muscle activation to muscle strength is not fully understood. Explosive neuromuscular performance, including the ability to initiate (the electromechanical delay, EMD) and develop force rapidly (termed, rate of force development, RFD) are considered essential for the performance of explosive sporting tasks and joint stabilisation and thus injury avoidance. The thesis aimed to improve our understanding of the contribution of neural factors to muscle performance, with a specific focus on explosive neuromuscular performance. The work in this thesis utilised a range of approaches to achieve this aim. Initially, the association between muscle activation and rate of force development and EMD was established. Comparison of unilateral and bilateral actions was then undertaken. Finally interventions with the aim to both negatively affect and improve muscle strength, which included fatigue and resistance training (RT), respectively was undertaken and the neural contributions to changes in performance established. Agonist activation during the early phase of voluntary force production was shown to be an important determinant of voluntary EMD, explaining 41% of its inter-individual variability. Agonist activation was an important determinant of early, but not late phase RFD. Use of bilateral actions resulted in a reduction in explosive strength, which was thought to be due to differences in postural stability between unilateral and bilateral strength tasks. The level of stabiliser activation was strongly related to the level of agonist activation during the early phase of explosive force development and had a high association with explosive force production. Task-specific adaptations following isoinertial RT, specifically, the greater increase in isoinertial lifting strength than maximal isometric strength were due to training-specific changes in the level of agonist activation. High-intensity fatigue achieved a more substantial decline in explosive than maximal isometric strength, and this was postulated to be due to neural mechanisms, specifically decreased agonist activation. This work provides an in depth analysis of the neural contributions to maximal muscle performance.

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43

Eriksson, Anders. "Strenght training and anabolic steroids : a comparative study of the trapezius, a shoulder muscle and the vastus lateralis, a thigh muscle, of strength trained athletes". Doctoral thesis, Umeå : Umeå universitet, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-869.

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44

Stavric, Verna A. "Muscle power after stroke". AUT University, 2007. http://hdl.handle.net/10292/131.

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Stroke is the leading cause of disability worldwide. It often leads to mobility limitations resulting from deficits in muscle performance. While reduced muscle strength and rate of force production have been reported, little is known about the power generating capability of people after stroke and its relationship to mobility. Research in other populations has found that measures of muscle power may have a greater association with activity performance than do measures of muscle force alone. Consequently, in an attempt to optimise power, investigators have focused on identifying ideal parameters within which to train for power. One such parameter is the identification of the loading level at which maximal power is generated. Literature reporting optimal loads from both young athletic and healthy older populations has yielded mixed results, making the applicability to a hemiparetic population difficult. The purpose of this study was to investigate muscle power performance at differing loads and to determine at what load muscle power is best elicited in hemiparetic and age and gender matched control groups. A secondary aim was to ascertain whether there is a relationship between the muscle power values obtained and activities such as gait, stair climbing and standing from a chair. Twenty nine hemiparetic volunteers and twenty nine age and gender matched controls were evaluated. Involved and uninvolved legs of the stroke group and a comparison leg of the control group underwent testing. Leg press muscle power was measured using a modified supine leg press machine at 30%, 50% and 70% of a one-repetition maximum (1-RM) load. Participants were positioned on the leg press machine and asked to push, with a single leg, as hard and as fast as they could. Data was collected via a mounted force platform and a linear transducer connected to a platform on which the participants lay. From these, power was able to be calculated. The activities were timed while being performed as fast as possible. The results showed that peak muscle power values differed significantly between the involved, uninvolved and control legs. Peak leg power in all three leg groups was greatest when pushing against a load of 30% of 1-RM. Involved leg peak power tested at 30% of 1-RM (Mean:240; SD:145 W) was significantly lower (p<0.05) than the uninvolved leg (Mean:506; SD:243 W). Both the involved and uninvolved legs generated significantly lower peak power (p<0.05) than the control leg (Mean:757; SD:292 W). Correlations were found between the involved leg peak power and gait speed and involved leg peak power and stair climbing (r=0.6-0.7, p<0.05). No correlation was found between paretic leg peak power and chair stands. The control group leg peak power demonstrated significant associations with the performance of all three activities.In summary, there were significant differences between the involved and the uninvolved leg in power production after stroke. As well, there are significant differences between the uninvolved leg and the leg of those not affected by stroke. Power was related to a number of activities.

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45

Wu, Cheng Kam-chee Polina, e 胡鄭金枝. "The effect of mental training in delaying muscle fatigue". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B29768585.

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46

Reid, Siobhan Louise. "Outcomes of an upper limb eccentric strength-training programme for adolescents with cerebral palsy". University of Western Australia. School of Human Movement and Exercise Science, 2007. http://theses.library.uwa.edu.au/adt-WU2008.0016.

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[Truncated abstract] Cerebral palsy is the most common physical disability in childhood (Reddihough & Collins, 2003). The most characteristic features of those with cerebral palsy are the physical disabilities that arise as a result of the brain lesion, including; spasticity, muscle weakness and atrophy, soft-tissue contracture and joint deformity. Strength training for young people with cerebral palsy aims to negate the debilitating effects of muscle weakness and improve function. Research need now be dedicated to investigating the mechanisms of strength-training, in an effort to optimise training routines and the prescription of strengthening protocols. The principal goal of the present research was to investigate the impact of eccentric strength training. A novel eccentrically based exercise intervention for the upper limb was implemented to ascertain the benefits on: (i) isokinetic torque development, (ii) the length-tension relationship of muscle (iii) EMG activity, (iv) 3D movement kinematics and (v) psychosocial benefits for children and their families. The analysis of changes in movement kinematics required the development of a reliable and repeatable upper limb 3D biomechanical model for clinical use, constituting chapter three of this thesis. ... This paper advocates the inclusion of measures of work/bodymass and width of the torque-angle relationship as important determinates of the functional integrity of muscle, and the use of EMG activation patterns to characterise neuromuscular mechanisms of training induced changes. The sixth paper aims to determine the effects of the eccentric training programme on upper limb 3D kinematics during functional tasks and to determine if these improvements were also evident on the Melbourne Assessment. Little change was evident in upper arm kinematics following the short-term eccentric training programme, however there was evidence in support of a decrease in compensatory movements at the thorax. The Melbourne Assessment failed to detect any significant changes in performance of functional upper limb tasks following the training programme. The results suggest that 3D kinematic analysis of upper body movement is a sensitive tool for the assessment of interventions for pathological populations. The aim of the seventh paper presented within this body of work was to ascertain the psychosocial outcomes for children with cerebral palsy and their families following the eccentric training programme. This study identified four main themes in the parent and participant responses to the programme; changes in physical health, psychosocial health, changes in activity and participation, and the impact of the psychosocial health of the child on the family were important to participants and their families. This paper reinforces the multi-dimensional nature of the benefits of strength-training, and advocates the assessment of interventions from perspective of the ICF (WHO, 2001). This work has established the reliability of an upper limb 3D biomechanical model for clinical use, and determined the neuromuscular, kinematic, functional and psychosocial outcomes of an upper limb eccentric training programme for adolescents with cerebral palsy and their families.

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47

Meyer, Rhonda D. (Rhonda Dawn). "Effects of Strength on Selected Psychomotor Performances of Healthy and Frail Elderly Females". Thesis, University of North Texas, 1993. https://digital.library.unt.edu/ark:/67531/metadc500976/.

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The purpose of this study was to compare muscle strength and psychomotor performance measures in healthy (n = 18) and frail (n = 21) groups of elderly women utilizing movements requiring various amounts of strength and ballistic action. Subjects were community-dwelling females ranging in age from 66-92 years. Evaluations of functional assessment of motor skills and grip strength occurred. Psychomotor performance was measured through production of aiming movements on a Digitizing Tablet. RT, MT, and movement kinematics (e.g., peak velocity, deceleration, movement adjustments) were evaluated. Differences between groups were apparent in quantity and quality of movement. Healthy subjects were stronger and faster than frail subjects, producing smoother movements with fewer adjustments. Strength appears to differentially affect healthy and frail samples and merits further exploration.

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48

Wilkins, Lisa Jacqueline. "The effect of graded and short-term, high-intensity exercise on expiratory muscle performance". Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-03032009-040735/.

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49

Creager, Leah C. "Effect of trunk endurance training on low back endurance & injury in collegiate gymnasts /". Connect to online version, 2009. http://minds.wisconsin.edu/handle/1793/45122.

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50

November, Rucia Vern-Clare. "The relationship between shoulder complex strength and throwing velocity in club cricketers". University of the Western Cape, 2016. http://hdl.handle.net/11394/5306.

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Magister Artium (Sport, Recreation and Exercise Science) - MA(SRES)
Over the years, cricket has progressed into a game of immense physical prowess, and evolved from a traditional and conservative game into a professional sport requiring very high levels of fitness and skill. The ability to throw a ball at high velocity and with great accuracy is critical for successful performance in many ball sports, including cricket. The aim of this study focussed on examining the relationship between isokinetic strength of the shoulder complex and throwing velocity amongst club cricketers in the age group of 18-32 years. The study used a quantitative methodology with a cross-sectional research design. A convenient sample of 40 male cricketers from the University of the Western Cape was tested. Isokinetic strength of external rotators (ER), internal rotators (IR) and ratios were measured using the Biodex Pro System 4 isokinetic dynamometer at two speeds, namely, 60º•sec-¹ and 90º•sec-¹. Throwing velocity was measured using a calibrated Cordless Speed/Radar Gun. The major findings of this study were the significant correlations between IR at 60º•sec-¹ and throwing velocity for the first team (r = 0.72; p = 0.01), second team (r = 0.67; p = 0.03), third team (r = 0.73; p = 0.01) and fourth team (r = 0.69; p = 0.02). The correlation between the strength ratio at 60º•sec-¹ and throwing velocity was significant for the first team (r = 0.76; p = 0.01), second team (r = 0.83; p = 0.002), third team (r = 0.70; p = 0.02) and fourth team (r = 0.94; p = 0.0001). In conclusion, shoulder strength plays a significant role in the throwing velocity amongst club cricketers. Specifically, the shoulder internal rotators were found to be a major influence in throwing velocity. Furthermore, the shoulder strength ratio is a strong predictor of shoulder strength performance.

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Tesi sul tema "Muscle strength"

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