Muscle Power

Aim: To examine the effects of rehabilitation on knee ranges of motion and muscle power after ACL reconstruction surgery. Method: In this study, 40 participants were examined who had ACL reconstruction. Research data was collected from the records since 20 th may 2022, 2022 to 10 th November, 2022 from Jinnah Hospital, Lahore. An ordinary follow-up examination was conducted at 1 st , 3 rd and 6 th week after procedure (Follow up rate was 90%). Range of motion were assessed and compared using statistical analysis. Level of significance was set at p<0.001. The study revealed that out of 40 participants, 13 (32.5%) were in the age range of 18-25 years, 2 (55%) were in the age range of 26-33 years and 5 (12.5%) were in the age range of 34-40 years with minimum age of 18 years and maximum age of 40 years. Out of 40 Participants, 37(92.5%) were males and 3(7.5%) females were included in the study. of 40 participants, 3(7.1%) had complications and difficulty in returning to healthy lifestyle after ACL surgery. There was significant difference between flexion and extension of knee across time. (p<0.001) Conclusion: The study reported that physical therapy rehabilitation post ACL reconstruction surgery greatly improved Knee flexion and extension range of motion. Post-operative complications were not reported in the majority of participants. Therefore, it is suggested that physical therapy rehabilitation is important for the return of knee function post ACL surgery.

Previous research has demonstrated that ingestion of essential amino acids and their metabolites induce anabolic effects with the potential to augment gains in lean body mass and strength after resistance exercise training. Purpose: The purpose of the present study was to examine the effects of an essential amino acid-based formula (Muscle Armori (MA); Abbott Laboratories, Abbott Park, IL) containing A-hydroxy-A-methylbutyrate (HMB) on hormonal and muscle damage markers in response to 12 wk of resistance exercise. Methods: Seventeen healthy men (mean body mass: 77.9 T 7.2 kg; mean height: 174.3 T 12.4 cm; mean age: 22.9 T 3.8 yr) were matched and randomized into two groups and performed 12 wk of periodized heavy resistance training while supplementing with either MA or an isocaloric, isonitrogenous placebo (CON). Every 2 wk during the 12-wk intervention, resting blood draws were obtained, and muscle strength and power were measured. In addition, blood draws were obtained before, during, and after a standardized resistance exercise challenge performed pre-, mid-, and posttraining. Results: Lean body mass, muscle strength, and muscle power significantly (P e 0.05) increased in both groups after training; however, MA supplementation augmented these responses to a significantly greater extent when compared with the CON group. MA supplementation promoted increases in resting and exercise-induced testosterone and resting growth hormone concentrations. In addition, MA reduced preexercise cortisol concentrations. Throughout the training protocol, MA attenuated circulating creatine kinase and malondealdehyde compared with the CON group, suggesting that MA might have influenced a reduction in muscle damage. Conclusion: MA supplementation beneficially affected training-induced changes in lean body mass, muscle strength, and power, as well as hormonal responses and markers of muscle damage in response to 12 wk of resistance exercise training when compared with an isonitrogenous control.

Background. Approximately 35,000 strokes occur annually in adults below the age of 40, and there is disappointingly little data describing their responses to rehabilitation. The purpose of this analysis was to determine the effects of Poststroke Optimization of Walking using Explosive Resistance (POWER) training in young (&lt;40 years) and older (&gt;60 years) adults and to describe relationships between training-induced improvements in muscular and locomotor function.Methods. Data was analyzed from 16 individuals with chronic stroke who participated in 24 sessions of POWER training. Outcomes included muscle power generation, self-selected walking speed (SSWS), 6-minute walk test, Fugl-Meyer motor assessment, Berg Balance Scale, and Dynamic Gait Index.Results. There were no significant differences between groups at baseline. Within-group comparisons revealed significant improvements in paretic and nonparetic knee extensor muscle power generation in both groups. Additionally, young p...

Background: Individuals with cerebral palsy have smaller muscle volumes normalised to body mass than their typically developing peers. The aim of this study is to investigate the relationship between lower limb muscle volume and body mass in young people with bilateral cerebral palsy and their typically developing peers. Methods: Twenty-five participants with bilateral cerebral palsy (aged 14.7±3.0 years, GMFCS level I-III) and 25 of their typically developing peers (aged 16.8±3.3 years) took part in this study. None of the participants had undergone orthopaedic surgery, botulinum toxin injections, or serial casting in the previous year. All participants underwent magnetic resonance imaging of both lower limbs. Nine major muscles of each lower limb were individually manually segmented and the muscle volumes calculated. Results: Body mass and total lower limb muscle volume were significantly linearly related in both the cerebral palsy (R 2 = 0.75, p<0.001) and typically developing (R 2 = 0.77, p<0.001) groups. The slope of the relationship between muscle volume and body mass was significantly shallower in the cerebral palsy group compared to the typically developing group (p=0.007). Conclusions: This cross-sectional study suggests that the increase in size of lower limb muscles relative to body mass is reduced in adolescents and young adults with cerebral palsy. Longitudinal studies are required to further investigate altered muscle growth trajectories in this group and their impact on long-term mobility.

Chronic fatigue syndrome (CFS) and Overtraining syndrome (OTS) are separate, complex conditions which have so many similar debilitating effects that it has led some researchers to conclude that OTS is a sub-condition of CFS. The purpose of this research was to compare the force and damage-recovery characteristics of skeletal muscle in CFS patients and control normals, after a single damaging bout of eccentric contractions in the non-dominant forearm flexors. The subjects (n = 25), a convenience sample were assigned to three groups; [1] CFS + eccentric damage (n = 8), [2] Control Damage (CD) + eccentric damage (n = 10), and [3] Control (ND) + no damage (n = 7). The research was carried out over a four week period using the following format. CFS & CD groups received eccentrically induced muscle damage of the forearm flexors by 35 isokinetic eccentric (7 x 5, 2 minutes recovery between sets) contractions at 90° sec-I with the forearm returning passively at 15°sec-1.

▶ muscle adaptation • ▶ training • ▶ electromyogram • ▶ power output • ▶ power spectral analysis Neuromuscular Fatigue after Resistance Training in maximal strength has not been reported . Despite the dynamic nature of most motor tasks in athletic and voluntary physical activities, many studies have frequently used isometric rather than dynamic fatiguing tasks to examine muscle fatigue, thus hindering any assessment of the eff ects of fatigue on power. Moreover, the eff ects of short-term heavy-resistance training on absolute and relative exerciseinduced neuromuscular fatigue (e.g. 5 sets of 10 repetitions at a relative or absolute load) following high-power dynamic tasks with a submaximal load remain to be elucidated. Thus, although enhanced maximal strength and power after a heavy resistance training program may give advantages to maintain power and / or enhance the recovery after a fatiguing task with the same submaximal absolute loading (i.e. same kg) as in pretraining, the question arises at to whether similar or even worse ability would be observed in maintaining muscle power after a dynamic fatiguing task with the same relative loading (i.e. same % of MVC) as in pretraining.

This study examined the impact of 4 weeks of either complete cessation of training (DTR) or a tapering period (TAP; short-term reduction of the strength training volume, while the intensity is kept high), subsequent to 16 weeks of periodized heavy resistance training (PRT) on strength/power gains and the underlying physiologic changes in basal circulating anabolic/catabolic hormones in strength-trained athletes. Forty-six physically active men were matched and randomly assigned to a TAP (n ϭ 11), DTR (n ϭ 14), or control group (C; n ϭ 21), subsequent to a 16-week PRT program. Muscular and power testing and blood draws to determine basal hormonal concentrations were conducted before the initiation of training (T0), after 16 weeks of training (T1), and after 4 weeks of either DTR or TAP (T2). Short-term DTR (4 weeks) results in significant decreases in maximal strength (Ϫ6 to Ϫ9%) and muscle power output (Ϫ17 and Ϫ14%) of the arm and leg extensor muscles. However, DTR had a significant (p Ͻ 0.01) larger effect on muscle power output more than on strength measurements of both upper and lower extremity muscles. Short-term (4 weeks) TAP reached further increases for leg (2%) and arm (2%) maximal strength, whereas no further changes were observed in both upper and lower muscle power output. Short-term DTR resulted in a tendency for elevation resting serum insulin-like growth factor (IGF)-1 concentrations, whereas the corresponding TAP experienced elevation in resting serum insulin-like binding protein-3 (IGFBP-3). These data indicated that DTR may induce larger declines in muscle power output than in maximal strength, whereas TAP may result in further strength enhancement (but not muscle power), mediated, in part, by training-related differences in IGF-1 and IGFBP-3 concentrations.

The purpose of this study was to examine the efficacy of 11 wk of resistance training to failure vs. nonfailure, followed by an identical 5-wk peaking period of maximal strength and power training for both groups as well as to examine the underlying physiological changes in basal circulating anabolic and catabolic hormones. Forty-two physically active men were matched and then randomly assigned to either a training to failure (RF; n = 14), nonfailure (NRF; n = 15), or control groups (C; n = 13). Muscular and power testing and blood draws to determine basal hormonal concentrations were conducted before the initiation of training (T0), after 6 wk of training (T1), after 11 wk of training (T2), and after 16 wk of training (T3). Both RF and NRF resulted in similar gains in 1-repetition maximum bench press (23 and 23%) and parallel squat (22 and 23%), muscle power output of the arm (27 and 28%) and leg extensor muscles (26 and 29%), and maximal number of repetitions performed during para...

Maximal concentric one repetition maximum half-squat (1RM HS ), bench-press (1RM BP ), power-load curves during concentric actions with loads ranging from 30% to 100% of 1RM HS and 1RM BP were examined in 70 male subjects divided into five groups: weightlifters (WL, n=11), handball players (HP, n=19), amateur road cyclists (RC, n=18), middle-distance runners (MDR, n=10) and age-matched control subjects (C, n=12). The 1RM HS values in WL, HP and RC were 50%, 29% and 28% greater, respectively, (P< 0.001-0.01) than those recorded for MDR and C. The half-squat average power outputs at all loads examined (from 30% to 100%) in WL and HP (P<0.001 at 45% and 60% with HP) were higher (P<0.05-0.001) than those in MDR, RC and C. Average power output at the load of 30% of 1RM HS in RC was higher (P<0.05) than that recorded in MDR and C. Maximal power output was produced at the load of 60% for HP, MDR and C, and at the load of 45% for WL and RC. The 1RM BP in WL was larger (P<0.05) than those recorded in HP, RC, MDR and C. In the bench press, average muscle power outputs in WL and HP were higher (P<0.05-0.001) than those in MDR, RC and C, and were maximized at a load of 30% of 1RM for WL and HP, and at 45% for RC, MDR and C. In addition, the velocities that elicited the maximal power in the lower extremities were lower (0.75 mAEs -1 ) than those occurring in the upper extremities (1 mAEs -1 ). The data suggest that the magnitude of the sport-related differences in strength and/or muscle power output may be explained in part by differences in muscle cross-sectional area, fibre type distribution and in the muscle mechanics of the upper and lower limbs as well as by training background.

To explore data on functioning in the medical records of patients with stroke by linking them to the ICF. [Subjects and Methods] The admission and discharge summaries of patients' electronic medical records (EMRs) were investigated. Information on functioning included in the summaries were mapped into the ICF. Each of the linked categories of ICF was analyzed using frequency and percentage analysis. [Results] Thirty stroke patients' records were evaluated. A total of 1,832 items on functioning in the EMRs were found to be linked to eightyfive categories of the ICF. The majority of those categories (52.9%) belonged to the body function domain, whereas only 8.2% were environment factors. Categories in the domain of activity and participation, and body structure were found to be 22.4% and 16.5% respectively. In each domain, the most frequently found categories were muscle power function (b730), structure of brain (s110), walking (d450), and products or substances for personal consumption (e110). [Conclusion] It was found that the admission and discharge summary in the current medical records of patients with stroke contained much noticeable information on functioning and the data on functioning may be linked to the ICF. Further study is needed to adapt ICF in Korean clinical settings.

Objective: To examine the association between radiographic classification of severe knee osteoarthritis and measurements of function, pain and power. Design: Cross-sectional study. Setting: Specialist orthopaedic hospital. Subjects: One hundred and twenty-three patients on the waiting list for elective knee arthroplasty. Outcome measures: Weight-bearing antero-posterior radiographs scored for severity of osteoarthritis using the Kellgren and Lawrence scale. Function measured using the function subscale of the WOMAC (Western Ontario and McMaster Universities) index, timed tests of walking speed and sit-to-stand. Pain measured using the pain subscale of the WOMAC index and a visual analogue scale. Extensor strength of the lower limb measured with the leg extensor power rig. Results: Within any radiographic grade there was considerable variation in function: WOMAC function for patients with grade 2 mean 64 (47 / 86), grade 3 mean 47 (12 / 89) grade 4 mean 45 (2 / 92). There was poor co...

The effects of a 10-wk unilateral knee extension strength training (ST) program on peak power and velocity at given absolute (force load) and relative (same % of 1 RM) resistances (loads) were examined in 30 older men (64 ± 7 yr) and 32 older women (62 ± 6 yr). As a result of the ST program, peak power (PP) increased significantly in both men and women at the same absolute (P &lt; 0.001) and relative loads (P &lt; 0.01). Men had a significantly greater increase in relative PP than women with ST at 60 % (P &lt; 0.01) and 70 % (P &lt; 0.001) of 1 RM when covarying for baseline differences and age. However, when each subject was tested at the same absolute load and when peak power was normalized for the muscle volume (MV) of the trained knee extensors (i.e., absolute muscle power quality, MPQ), women increased their MPQ by 9% (P &lt; 0.05), whereas men did not change. Both men and women increased their absolute peak movement velocity (PV) (P &lt; 0.001), but decreased their relative PV...

Objectives-Peak torque expresses a point output which may, but does not always, correlate well with full range output measures such as work or power, particularly in a rehabilitating muscle. This study evaluates isokinetic performance variables, particularly (a) flexor to extensor work and power output ratios of upper and lower extremities and (b) overall upper to lower extremity work and power ratios, in intercollegiate athletes. The purpose was to ascertain how speeds of 30 and 180 degrees/s influence agonist to antagonist ratios for torque, work, and power and to determine the eVects of these speeds on upper to lower limb flexor (F), extensor (E), and combined (F + E) ratios, as a guide to rehabilitation protocols and outcomes after injury. Methods-Twenty seven athletic men without upper or lower extremity clinical histories were tested isokinetically at slow and moderately fast speeds likely to be encountered in early stages of rehabilitation after injury. Seated knee extensor and flexor outputs, particularly work and power, were investigated, as were full range elbow extensor and flexor outputs. The subjects were morphologically similar in linearity and muscularity (coefficient of variation 4.17%) so that standardisation of isokinetic outputs to body mass eVectively normalised for strength diVerences due to body size. Peak torque (N.m/kg), total work (J/kg), and average power (W/kg) for elbow and knee flexions and extensions were measured on a Cybex 6000 isokinetic dynamometer. With respect to the raw data, the four test conditions (F at 30 degrees/s; E at 30 degrees/s; F at 180 degrees/s; E at 180 degrees/s) were analysed by one way analysis of variance. Reciprocal (agonist to antagonist) F to E ratios of the upper and lower extremities were calculated, as were upper to lower extremity flexor, extensor, and combined (F + E) ratios. Speed related diVerences between the derived ratios were analysed by Student's t tests (related samples). Results-At the speeds tested all torque responses exhibited velocity related decrements at rates that kept flexor to extensor ratios and upper to lower extremity ratios constant (p>0.05) for work and power. All upper extremity relative torque, work, and power flexion responses were equal to extension responses (p>0.05) regardless of speed. Conversely, all lower extremity relative measures of torque, work, and power of flexors were significantly lower than extensor responses. In the case of both upper and lower extremities, work and power F to E ratios were unaVected by speed. Moreover, increasing speed from 30 to 180 degrees/s had no eVect on upper to lower extremity work and power ratios, whether for flexion, extension, or flexion and extension combined. Conclusions-Peak torque responses may not adequately reflect tension development through an extensive range of motion. Total work produced and mean power generated, on the other hand, are highly relevant measures of performance, and these, expressed as F to E ratios, are unaVected by speeds of 30 and 180 degrees/s, whether for upper or lower extremities or for upper to lower extremities. In this sample, regardless of speed, the upper extremity produced 55% of the work and 39% of the power of the lower extremity, when flexor and extensor outputs were combined. Injured athletes are, in the early stages of function restoration, often not able to exert tension at fast speeds. An understanding of upper to lower extremity muscular work and power ratios has important implications for muscle strengthening after injury. Knowledge of normal upper to lower extremity work and power output ratios at slow to moderately fast isokinetic speeds is particularly useful in cases of bilateral upper (or lower) extremity rehabilitation, when the performance of a contralateral limb cannot be used as a yardstick.

The aim of this study was to examine changes in body mass (BM) and power-related measures in Olympic boxers during an official qualifying boxing tournament. Fourteen elite amateur boxers from the Brazilian National Team (eight men and six women) participated in this study. Athletes performed three fights in four days against the same opponent of the same weight-category. Before and immediately after every fight, BM, countermovement jump (CMJ) height, and power production in the bench-press and half-squat exercises were assessed in the same order and on the same time of the day. A two-way repeated-measures ANOVA with the Bonferroni post-hoc analysis was used to determine the variations between pre- and post-measures. The statistical significance was set as p &lt; 0.05. The athletes were able to maintain their baseline weight and physical performance throughout the experimental period, as shown by the lack of significant changes in BM, CMJ height, and upper- and lower-limb power outpu...

effect of short-term optimum power load training on the punching impact of elite boxers. J Strength Cond Res XX(X): 000-000, 2019-This study examined the changes in bench press (BP), jump squat (JS), and half-squat (HS) power outputs induced by a short-term (1 week) training scheme based on the optimum power load (OPL) applied to national boxing athletes and measured the transference effect coefficient (TEC) of these exercises on punching impact. Eight elite boxing athletes from the Brazilian National team participated in this study. Athletes were tested before and after 3 power-oriented training sessions performed at the OPL. The physical assessments comprised punching impact measures (jabs and crosses) at fixed and self-selected distances, and bar-power output in BP, HS, and JS exercises. Magnitude-based differences were used to compare pre-training and post-training sessions. Transference effect coefficient was calculated as the ratio between the result gain in the "untrained exercises" (punching impact in jabs and crosses) and "trained exercises" (HS, JS, and BP), for variables presenting an effect size of at least 0.2. The OPL training elicited meaningful increases in the punching impact forces (;8%) and in both JS and HS power outputs (;12 and ;14%, respectively), but not in BP power output. There was an effective transference (TEC 5 ;0.80) of JS and HS performance gains to punching impact force, suggesting that increases in lower-limb power can be directly transferred to punching impact. These results provide coaches and practitioners with valuable information about how to rapidly and effectively increase the punching impact force of elite amateur boxers.

The purpose of this case study was to examine the effects of a resistance-training program based on the optimum power loads (OPL) method on neuromuscular performance of Olympic boxing athletes during preparation for the Rio-2016 Olympic Games. Twelve elite amateur boxers from the Brazilian National Olympic Team participated in this study. Athletes were assessed at four time-points, over two consecutive competitive seasons. In the first season (considered as &quot;control period&quot;), the athletes executed a non-controlled strength-power training program for 10 weeks. In the second season (a seven-week experimental period), the elite boxers performed 14 power-oriented training sessions, comprising bench press (BP) and jump squat (JS) exercises at the OPL. Maximum bar-power output in BP and JS exercises was measured pre and post both training phases. Magnitude-based inferences were used to compare changes in pre and post training tests. Bar-power outputs increased meaningfully in bo...

Purpose: Being able to rise from a chair is paramount for independent living and is strongly influenced by the ability of the lower limbs to exert mechanical power. This study assessed minimal thresholds of lower-limb relative muscle power required to perform the sit-to-stand (STS) task in older adults and its association with mobility limitations and disability. Methods: A total of 11,583 older adults (age: 60−103 years old) participated in this investigation. The 5-rep and 30-s versions of the STS test were used to assess chair rising ability. Relative power was calculated by the STS muscle power test. The minimum thresholds of power required to perform the STS tests were derived from the minimum values (i.e. 'floor' effect) reported in the power tests through regression analyses. Mobility limitations and disability in activities of daily living (ADL) were recorded. Results: For the average older man and woman, the thresholds to complete five STS repetitions were 1.1 and 1.0 W•kg-1 , respectively, while the thresholds to complete one STS repetition were 0.3 W•kg-1 in both sexes. These thresholds increased linearly with height (5-and 1-rep, respectively: +0.13 and +0.03 W•kg-1 per 10-cm increase; both p<0.001), and did not differ by sex or testing condition (both p≥0.259). All participants with relative power below the 5-rep threshold presented mobility limitations and 51−56% of women and 36−49% of men also showed disability in ADL (all χ 2 ≥290.4; p<0.001).

Skeletal muscle power has been demonstrated to be a stronger predictor of functional limitations than any other physical capability. However, no validated alternatives exist to the usually expensive instruments and/or time-consuming methods to evaluate muscle power in older populations. Our aim was to validate an easily applicable procedure to assess muscle power in large cohort studies and the clinical setting and to assess its association with other age-related outcomes. Forty community dwelling older adults (70-87 years) and 1804 older subjects (67-101 years) participating in the Toledo Study for Healthy Aging were included in this investigation. Sit-to-stand (STS) velocity and muscle power were calculated using the subject&#39;s body mass and height, chair height and the time needed to complete five STS repetitions, and compared with those obtained in the leg press exercise using a linear position transducer. In addition, STS performance, physical (gait speed) and cognitive func...

This study investigated the physiological and gender determinants of the age-related loss of muscle power in 31 healthy middle-aged adults (aged 40-55 years), 28 healthy older adults (70-85 years) and 34 mobility-limited older adults (70-85 years). We hypothesized that leg extensor muscle power would be significantly lower in mobility-limited elders relative to both healthy groups and sought to characterize the physiological mechanisms associated with the reduction of muscle power with aging. Computed tomography was utilized to assess mid-thigh body composition and calculate specific muscle power and strength. Surface electromyography was used to assess rate of neuromuscular activation and muscle biopsies were taken to evaluate single muscle fiber contractile properties. Peak muscle power, strength, muscle cross-sectional area, specific muscle power and rate of neuromuscular activation were significantly lower among mobility-limited elders compared to both healthy groups (P ≤ 0.05). Mobility-limited older participants had greater deposits of intermuscular adipose tissue (P < 0.001). Single fiber contractile properties of type I and type IIA muscle fibers were preserved in mobility-limited elders relative to both healthy groups. Male gender was associated with greater decrements in peak and specific muscle power among mobility-limited participants. Impairments in the rate of neuromuscular activation and concomitant reductions in muscle quality are important physiological mechanisms contributing to muscle power deficits and mobility limitations. The dissociation between age-related changes at the whole muscle and single fiber level suggest that, even among older adults with overt mobility problems, contractile properties of surviving muscle fibers are preserved in an attempt to maintain overall muscle function.

The purpose of this study was to investigate the relationship between adolescents’ biological maturation level and their muscle power, as well as their overall muscle strength. Overall, 691 adolescents (414 boys and 277 girls) aged 12.01–11.96 (measured for body mass, body height as well as vertical jump, muscle power, and muscle strength). There was a statistically significant difference in terms of average right and left grip strength, vertical jump, and power in the late maturation group. For the body height and vertical jump averages in male adolescents, it was observed that the body height and vertical jump averages in the late group were significantly lower than in the early and on-time maturation groups. For female adolescents’ chronological age, sitting height, body mass, BMI, left and right grip strength, and power averages were found to be significantly higher compared with the on-time group (p &lt; 0.05). It was established that biological maturation has a substantial lin...

There are many factors that affect Pencak Silat skills, namely the elements of physical condition and kicks. Based on the background in the introduction, it was found that the frequency of sickle kicks is related to the power of the leg muscles. Purpose. Thus, the purpose of this study is to find out how much there is a correlation between leg muscle power and the frequency of sickle kicks in pencak silat athletes. Material and methods. This type of research is correlational research using a quantitative approach. The population in this study is all pencak silat athletes in the Muna Regency Pencak Sor La Ode Pandu Organization. There were 30 male athletes who were taken as samples through purposive sampling techniques. There are several instruments used to collect data: the vertical jump test to measure leg muscle power and the sickle kick test by counting the number of left and right foot kicks for 30 seconds each to measure the frequency of sickle kicks. Results. The results showed that there is a significant correlation between leg muscle power and sickle kick frequency; this can be seen from the acquisition of sig values. 0.019 < 0.05, and the calculated r value = 0.425 > r table (0.05 = 0.361), while the determinant coefficient (R2) = 0.18, which means that the power of the limb muscles contributes to the frequency of sickle kicks by 18%. While 82% is influenced by other elements of physical conditions. Conclusions. Based on the research that has been done, it can be concluded that there is a significant correlation between leg muscle power and the frequency of pencak silat sickle kicks. The sickle kick is a kick that is often used in matches. A good sickle kick certainly requires elements of good physical condition as well. Leg muscle power is one of the elements of physical condition that most determine the outcome of a sickle kick. Good leg muscle power requires a well-defined form of exercise. Exercises such as polymetrics and ballistics can increase leg muscle power. The authors emphasize the importance of further research to expand what they did in this study, including expanding the sample size, other influencing variables, and the role of teachers and trainers in Pencak Silat learning. This needs to be done in depth to validate the results of this study.

To verify the effects of short-term plyometric training (PM) on body composition, flexibility and muscle power output in female Futsal athletes. [Subjects and Methods] Twenty female Futsal athletes (19.5 ± 1.29 years) equally and randomly divided into control and experimental groups were submitted to a sit-and-reach flexibility test, body composition measures and horizontal jump, at baseline and one day after the final training session. Both groups retained their training routines while only the experimental group participated in an additional 25 minutes of PM 2 times a week over 4 weeks. [Results] The experimental group showed higher values of flexibility and muscle power and lower body fat after the intervention in comparison to the baseline and control group. In addition, the effect size within-group after intervention indicated a moderate, large and very large effect for body fat, flexibility and muscle power, respectively. [Conclusion] These results show that plyometric training may be effective in reducing body fat and increasing flexibility and muscle power in female Futsal athletes. Thus, it may suggest that PM can be applied in the field of preventive physical therapy.

A number of recent studies have revealed an approximately linear force-velocity (F-V) and, consequently, a parabolic power-velocity (P-V) relationship of multi-joint tasks. However, the measurement characteristics of their parameters have been neglected, particularly those regarding arm muscles, which could be a problem for using the linear F-V model in both research and routine testing. Therefore, the aims of the present study were to evaluate the strength, shape, reliability, and concurrent validity of the F-V relationship of arm muscles. Twelve healthy participants performed maximum bench press throws against loads ranging from 20 to 70 % of their maximum strength, and linear regression model was applied on the obtained range of F and V data. One-repetition maximum bench press and medicine ball throw tests were also conducted. The observed individual F-V relationships were exceptionally strong (r = 0.96-0.99; all P &lt; 0.05) and fairly linear, although it remains unresolved whet...

On behalf of the American Society for Parenteral and Enteral Nutrition (ASPEN), a systematic review was conducted to evaluate the best available evidence regarding the validity of relevant body composition methods (eg, dual energy X-ray absorptiometry [DXA], ultrasound [US], and bioelectrical impedance analysis [BIA]) in clinical populations. The guidelines targeted adults >18 years of age with a potentially inflammatory condition or pathological end point associated with a specific disease or clinical condition. In total, 7375 studies were retrieved, and 15 DXA, 7 US, and 23 BIA studies provided applicable data. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses was used to assess the diagnostic accuracy of the test method against a "gold standard" reference. The Grading of Recommendations, Assessment, Development and Evaluation criteria were used to separate the evaluation of the body of evidence from the recommendations. Based on a limited number of studies and expert opinion, DXA is recommended for the assessment of fat mass in patients with a variety of disease states; however, the validity of DXA for lean mass assessment in any clinical population remains unknown. No recommendations can be made at this time to support the use of US or BIA in the clinical setting, as data to support its validity in any specific patient population are limited in scope or by the proprietary nature of manufacture-specific BIA regression models to procure body composition data, respectively. Directions for future research are provided. These clinical guidelines were approved by the ASPEN Board of Directors. (JPEN J

A predição da "performance" motora vem sendo uma questão básica para a ciência do esporte. Vários tipos de testes vêm sendo utilizados para tal, sendo os testes que avaliam a função muscular os mais utilizados. A especificidade do teste tem importância fundamental para que ele possua uma boa capacidade preditiva, contudo é muito difícil selecionar testes que simulem a "performance" motora mantendo valores elevados de validade e fidedignidade. Os objetivos do presente estudo foram: a) determinar a capacidade de predição da "performance" no salto vertical através de testes isocinéticos em diferentes faixas etárias; b) comparar os grupos para verificar se a "performance" no salto vertical e no teste isocinético evoluía na mesma razão, com o aumento da idade cronológica. A amostra foi composta por 30 jogadores de voleibol, divididos em três grupos por idade cronológica; jogadores com mais de 20 anos (G 20); jogadores entre 17 e 19 anos (G 17) e jogadores entre 15 e 16 anos (G 15). Os indivíduos foram submetidos a um teste de força para a musculatura extensora do joelho (dinamômetro Cybex 6000 ®), nas velocidades angulares de 180, 240 e 300 0 /s e a um teste de salto vertical ("Ergo Jump"), utilizando-se o "Squat Jump" (SJ). Somente o G 20 obteve uma equação na qual o valor da variável obtida foi significante (p < 0,05). A comparação entre os grupos revelou que o G 20 e o G 17 significantemente mais fortes para todas as velocidades angulares do que o G 15 , enquanto para o salto vertical somente o G 20 foi superior ao G 15. Esse estudo indica que a variável de "força isocinética" não é um bom preditor da "performance" no salto vertical e que as variáveis não evoluíram na mesma razão com o aumento da idade cronológica.

Objective: To evaluate the activity of the adductor and abductor muscle groups of the hip in young adults by using an isokinetic dynamometer. Method: 20 male volunteers were selected, with ages varying between 21 and 30 years for evaluation on a Cybex 6000 isokinetic dynamometer, at angular speeds of 60°/s and 120°/s. Results: In relation to the dominance, it did not show any statistically significant differences at the two studied speeds. At these two speeds the maximum torque, the total work, and the average power presented statistically significant differences in all the comparisons. Comparing the muscle groups revealed statistically significant differences for the total work, with higher average values in the abductor muscle group studied at both speeds and the average power found higher mean values at 120°/s in the same muscle group. Conclusion: There was no statistically significant difference in relation to dominance. When comparing speeds, all variables showed a statistically significant difference in the prevalence of maximum torque and total work at 60°/s and average power at 120°/s. The statistical comparison between muscle groups showed significant differences for the total work at both speeds and the average power at a rate of 120°/s.

The use of creatine monohydrate (Cr) in professional soccer is widely documented. However, the effect of low doses of Cr on the physical performance of young soccer players is unknown. This study determined the effect of a low dose of orally administered Cr on muscle power after acute intra-session fatigue in young soccer players. Twenty-eight young soccer players (mean age = 17.1 ± 0.9 years) were randomly assigned to either a Cr (n = 14, 0.3 g•kg -1 •day -1 for 14 days) or placebo group (n = 14), using a two-group matched, double-blind, placebo-controlled design. Before and after supplementation, participants performed 21 repetitions of 30 m (fatigue induction), and then, to measure muscle power, they performed four repetitions in half back squat (HBS) at 65% of 1RM. Statistical analysis included a two-factor ANOVA (p < 0.05). Bar velocity at HBS, time: p = 0.0006, ts 2024, 16, x FOR PEER REVIEW 6 of 11 2 p = 0.009. At the end of the study, it was found that, after the induction of acute intra-session fatigue, a low dose of Cr administered orally increases muscle power in young soccer players.

Vilniaus universiteto Medicinos fakulteto Žmogaus ir medicininės genetikos katedra 1 , Lietuvos olimpinis sporto centras 2 , Vilniaus pedagoginis universitetas 3 Santrauka Darbo tikslas -ištirti Lietuvos didelio meistriškumo sportininkų ACE [I/D] ir PGC1A [G/A] polimorfizmų reikšmę fiziniam pajėgumui. Fizinis pajėgumas yra tipiškas kiekybinis daugiaveiksnis paveldėjimas, kurio fenotipams poveikį daro tiek daugelis genų, tiek aplinkos veiksniai. Dažniausiai sportuojančio žmogaus morfologiniai ir funkciniai rodikliai siejami su tam tikrų genų vieno nukleotido polimorfizmu. Skirtingi to paties geno aleliai gali turėti skirtingą įtaką žmogaus fiziniam išsivystymui ir darbingumui. ACE (angiotenziną konvertuojančio fermento) genas yra vienas iš genų, kurių įtaka žmogaus fiziniam pajėgumui buvo atskleista pirmiausia. Ankstesniais tyrimais nustatyta, kad šio geno Alu sekos intarpo buvimas ar nebuvimas ([I/D] polimorfizmas) gali būti susijęs su profesionaliu sportiniu pajėgumu. Tačiau ACE [I/D] polimorfizmo tyrimų, atliktų įvairiose populiacijose, rezultatai yra prieštaringi. Raktažodžiai: ACE ir PGC1A genų variacijos, fizinis pajėgumas, didelio meistriškumo sportininkai.

There are many factors that affect Pencak Silat skills, namely the elements of physical condition and kicks. Based on the background in the introduction, it was found that the frequency of sickle kicks is related to the power of the leg muscles. Purpose. Thus, the purpose of this study is to find out how much there is a correlation between leg muscle power and the frequency of sickle kicks in pencak silat athletes. Material and methods. This type of research is correlational research using a quantitative approach. The population in this study is all pencak silat athletes in the Muna Regency Pencak Sor La Ode Pandu Organization. There were 30 male athletes who were taken as samples through purposive sampling techniques. There are several instruments used to collect data: the vertical jump test to measure leg muscle power and the sickle kick test by counting the number of left and right foot kicks for 30 seconds each to measure the frequency of sickle kicks. Results. The results showed that there is a significant correlation between leg muscle power and sickle kick frequency; this can be seen from the acquisition of sig values. 0.019 < 0.05, and the calculated r value = 0.425 > r table (0.05 = 0.361), while the determinant coefficient (R2) = 0.18, which means that the power of the limb muscles contributes to the frequency of sickle kicks by 18%. While 82% is influenced by other elements of physical conditions. Conclusions. Based on the research that has been done, it can be concluded that there is a significant correlation between leg muscle power and the frequency of pencak silat sickle kicks. The sickle kick is a kick that is often used in matches. A good sickle kick certainly requires elements of good physical condition as well. Leg muscle power is one of the elements of physical condition that most determine the outcome of a sickle kick. Good leg muscle power requires a well-defined form of exercise. Exercises such as polymetrics and ballistics can increase leg muscle power. The authors emphasize the importance of further research to expand what they did in this study, including expanding the sample size, other influencing variables, and the role of teachers and trainers in Pencak Silat learning. This needs to be done in depth to validate the results of this study.

The age-related decline in muscle function, particularly muscle power, is associated with increased risk of important clinical outcomes. Physical activity is an important determinant of muscle function, and different types of physical activity e.g. power-based versus endurance-based exercise appear to have differential effects on muscle power. Cross-sectional studies suggest that participation in power-based exercise is associated with greater muscle power across adulthood but this has not been investigated longitudinally. We recruited eighty-nine male and female power and endurance master athletes (sprint and distance runners respectively, baseline age 35–90y). Using jumping mechanography, we measured lower limb muscle function during a vertical jump including at least two testing sessions longitudinally over 4.5 ± 2.4y. We examined effects of time, discipline (power/endurance) and sex in addition to two- and three-way interactions using linear mixed-effects models. Peak relative p...

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Este estudo objetivou identificar a potência de membros inferiores em jogadores de futebol e futsal, comparando o counter movement jump (CMJ) entre modalidades, posições adotadas e categorias. Participaram 61 atletas de futebol das categorias Sub17, Sub20 e profissional e 28 de futsal das categorias Sub20 e profissional. Utilizou-se uma plataforma de força Quattro Jump do tipo piezoelétrica. Foi utilizada estatística descritiva, teste t de Student e análise de variância a p < .05. Não foi reportada diferença significativa no CMJ entre os atletas de futebol e futsal (p = .85). Entre as posições adotadas pelos jogadores de futebol encontrou-se diferença significativa (p = .02) apenas entre os centrais e os médios. Nos atletas de futsal não foi verificada diferença significativa entre as posições (p = .69). Quando comparadas as categorias também não foram constatadas diferenças significativas, tanto no futebol (p = .12), quanto no futsal (p = .47). Pode-se concluir que os atletas de futebol e futsal parecem apresentar níveis semelhantes de potência muscular. Os centrais apresentaram maiores níveis de potência quando comparados aos médios, porém no futsal os atletas apresentaram níveis similares de potência. Independente da categoria, tanto os atletas de futebol quanto de futsal, apresentaram níveis semelhantes de potência muscular.

This randomized controlled trial examined the effects of multicomponent training on muscle power output, muscle mass, and muscle tissue attenuation; the risk of falls; and functional outcomes in frail nonagenarians. Twenty-four elderly (91.9±4.1 years old) were randomized into intervention or control group. The intervention group performed a twice-weekly, 12week multicomponent exercise program composed of muscle power training (8-10 repetitions, 40-60 % of the one-repetition maximum) combined with balance and gait retraining. Strength and power tests were performed on the upper and lower limbs. Gait velocity was assessed using the 5-m habitual gait and the timeup-and-go (TUG) tests with and without dual-task performance. Balance was assessed using the FICSIT-4 tests. The ability to rise from a chair test was assessed, and data on the incidence and risk of falls were assessed using questionnaires. Functional status was assessed before measurements with the Barthel Index. Midthigh lower extremity muscle mass and muscle fat infiltration were assessed using computed tomography. The intervention group showed significantly improved TUG with single and dual tasks, rise from a chair and balance performance (P<0.01), and a reduced incidence of falls. In addition, the intervention group showed enhanced muscle power and strength (P<0.01). Moreover, there were significant increases in the total and high-density muscle cross-sectional area in the intervention group. The control group significantly reduced strength and functional outcomes. Routine multicomponent exercise intervention should be prescribed to nonagenarians because overall physical outcomes are improved in this population.

We propose a novel control method for lowerlimb assist that produces a virtual modification of the mechanical impedance of the human limbs. This effect is accomplished through the use of an exoskeleton that displays active impedance. The proposed method is aimed at improving the dynamic response of the human limbs, while preserving the user's control authority. Our goal is to use active-impedance exoskeleton control to improve the user's agility of motion, for example by reducing the average time needed to complete a movement. Our control method has been implemented in a 1-DOF exoskeleton designed to assist human subjects performing knee flexions and extensions. In this paper we discuss an initial study on the effect of negative exoskeleton damping (a particular case of active-impedance control) on the subject's time to complete a target-reaching motion. Experimental results show this effect to be statistically significant. On average, subjects were able to reduce the time to complete the motion by 16%.

The effects of a 16-week training period (2 days per week) of resistance training alone (upper-and lower-body extremity exercises) (S), endurance training alone (cycling exercise) (E), or combined resistance (once weekly) and endurance (once weekly) training (SE) on muscle mass, maximal strength (1RM) and power of the leg and arm extensor muscles, maximal workload (W max) and submaximal blood lactate accumulation by using an incremental cycling test were examined in middle-aged men [S, n=11, 43 (2) years; E, n=10, 42 (2) years; SE, n=10, 41 (3) years]. During the early phase of training (from week 0 to week 8), the increase 1RM leg strength was similar in both S (22%) and SE (24%) groups, while the increase at week 16 in S (45%) was larger (P<0.05) than that recorded in SE (37%). During the 16-week training period, the increases in power of the leg extensors at 30% and 45% of 1RM were similar in all groups tested. However, the increases in leg power at the loads of 60% and 70% of 1RM at week 16 in S and SE were larger (P<0.05) than those recorded in E, and the increase in power of the arm extensors was larger (P<0.05) in S than in SE (P<0.05) and E (n.s.). No significant differences were observed in the magnitude of the increases in W max between E (14%), SE (12%) and E (10%) during the 16-week training period. During the last 8 weeks of training, the increases in W max in E and SE were greater (P<0.05-0.01) than that observed in S (n.s.). No significant differences between the groups were observed in the training-induced changes in submaximal blood lactate accumulation. Significant decreases (P<0.05-0.01) in average heart rate were observed after 16 weeks of training in 150 W and 180 W in SE and E, whereas no changes were recorded in S. The data indicate that low-frequency combined training of the leg extensors in previously untrained middle-aged men results in a lower maximal leg strength development only after prolonged training, but does not necessarily affect the development of leg muscle power and cardiovascular fitness recorded in the cycling test when compared with either mode of training alone.

Insulin-like growth factor-I (IGF-1) is a hormone associated with multiple physiologic outcomes including increased muscle growth and repair as well as uncontrolled cell growth, i.e. cancer. Both exercise and nutritional status (in particular protein intake) have been observed to influence circulating IGF-1 concentration but the magnitude and direction of effects have been inconsistent. In addition, it was previously unknown if exercise modulated the effect of dietary protein on IGF-1 concentration or vice-versa. This PhD research consisted of four studies designed to: 1) summarise past literature on exercise and IGF-1 concentration, 2) summarise previous research on dietary protein and IGF-1 concentration, 3) assess the acute response of exercise and/or dietary protein on IGF-1 concentration, and 4) investigate cross-sectional associations between physical activity, diet, and IGF-1

The age-related decline in muscle function, particularly muscle power, is associated with increased risk of important clinical outcomes. Physical activity is an important determinant of muscle function, and different types of physical activity e.g. power-based versus endurance-based exercise appear to have differential effects on muscle power. Cross-sectional studies suggest that participation in power-based exercise is associated with greater muscle power across adulthood but this has not been investigated longitudinally. We recruited eighty-nine male and female power and endurance master athletes (sprint and distance runners respectively, baseline age 35–90y). Using jumping mechanography, we measured lower limb muscle function during a vertical jump including at least two testing sessions longitudinally over 4.5 ± 2.4y. We examined effects of time, discipline (power/endurance) and sex in addition to two- and three-way interactions using linear mixed-effects models. Peak relative p...

Complex training is an exercise method that combines plyometrics with strength training. This exercise is an exercise used to increase muscle power. This study aims to determine the effect of training of complex training methods towards leg muscle power and arm muscle power for adolescent volleyball athletes. The method used in this study is an experiment with a control group pretest - post test design. Subjects in this study are 23 adolescent volleyball athletes (14-17 years old) with 12 males and 11 females, who are divided into two groups of experimental groups (n = 12) and control groups (n = 11) with randomized matched pair design based on the ranking of the vertical jump ability. Instrument used in this study is vertical jump test (leg power) and the medicine ball throw test (arm power). The data analysis technique uses the paired t-test with a significance level of α = 0.05. The results show that training using a complex training method provides a good benefit in improving le...

Objectives-After stroke, abnormal arm posture due to spasticity in a functionally useless arm may interfere with self care tasks. In these patients botulinum toxin treatment presents an opportunity to reduce disability. The purpose was to investigate whether reduction in spasticity after botulinum toxin treatment translates into reduction in disability and carer burden. Methods-Forty patients with stroke with spasticity in a functionally useless arm (median duration 3.1 years) were randomised to receive intramuscular botulinum toxin type A (BT-A; Dysport) (n=20) or placebo (n=20) in a total dose of 1000 MU divided between elbow, wrist, and finger flexors. Spasticity (using the modified Ashworth scale), muscle power, joint movement, and pain were assessed. Disability and carer burden were measured using an eight item and a four item scale respectively. Two baseline and three posttreatment assessments (weeks 2, 6, and 12) were made. Concurrent treatments as far as possible remained unchanged and not optimised. Results-Disability improved at week 6 with BT-A compared with placebo. This eVect, present at week 2, wore oV by week 12. Reduction in carer burden was seen at week 6 with BT-A and continued for at least 12 weeks. Forearm flexor spasticity was reduced with BT-A up to 12 weeks after treatment. Although significant improvement in elbow flexor spasticity was seen at week 2 with BT-A compared with placebo, this eVect was not evident at weeks 6 and 12. Arm pain was not improved after BT-A. Grip strength was reduced with BT-A. No serious BT-A related adverse eVects were reported. Conclusion-BT-A is useful for treating patients with stroke who have self care diYculties due to arm spasticity. The decision to treat should also include relief of carer burden. As muscle weakness may occur, its potential impact on functional activities must be assessed before intervention.

Background: Knee osteoarthritis is one of the most prevalent conditions. According to world health organization the knee osteoarthritis is the fourth most important cause of disability in women and eight most important causes in men. Various methods have been used like high speed cinematography, force platform etc but no study was done by using pen marking analysis to compare the gait parameters of osteoarthritis patients and healthy individuals. Purpose of study: To compare gait parameter that is step length, step width, stride length, walking velocity and cadence of osteoarthritis patients and healthy individuals. Materials and Methods: This experimental cross sectional study conducted at Guru Jambheshawar University of Science and Technology, Hisar. 30 subjects were taken as per selection criteria which included both male and female between the ages of 40 to 65 years. They were divided into two groups that is group A has osteoarthritis patients (n = 15) and group B has normal healthy subjects (n = 15). Step length, Step width, Stride length, Walking velocity and Cadence were taken as outcome measurement parameters. Results: Comparison was made between the gait parameters within group and between the groups by using ttest for statistical analysis. Result shows statistically significant difference in gait parameters between the patient group and healthy individuals. Patient group have lower step length (34%), stride length (33%), walking velocity (48%) and cadence (31%) and greater step width (44%) then the control group. Females with knee osteoarthritis have lower values for step length, stride length, walking velocity and cadence and greater step width then control group females. Males with knee osteoarthritis have lower values for step length, walking velocity and cadence than the control group males. Conclusion: Knee osteoarthritis shows significant difference in the gait parameters between the osteoarthritis patients and healthy individuals and between the genders.

This paper deals with EMG-driven torque estimation and optimal adaptive impedance control during robot-aided rehabilitation. In this preliminary and feasibility study, the proposed framework was evaluated considering an active knee orthosis and only healthy subjects. First, a simplified and optimized musculoskeletal model is used to compute the estimate of user's torque considering electromyographic (EMG) signals taken from selected muscles acting during flexion and extension movements. The model optimization is performed by comparing the estimated torque from EMG with the torque generated by the inverse dynamics tool of the OpenSim software. As an alternative solution, a multilayer perceptron neural network (NN) is proposed to map the EMG signals to the user's torque. The proposed approaches are evaluated by a set of healthy subjects wearing the knee orthosis and performing a protocol created for user-robot interaction analysis. Then, an EMG-driven adaptive impedance control is proposed to improve the user participation during the rehabilitation session. The approach is based on an optimal solution which considers the position error and the robot assistance level. The experimental results indicate the use of EMG signals is feasible for adaptive control strategies, taking into account the current condition of the user and optimizing the robot assistance.