Extension Peak Torque Research Articles

Effect of External Counterpulsation on Exercise Recovery in Team Sport Athletes.

External counterpulsation (ECP), an electrocardiogram-led sequential compression of lower limbs, has been recently proposed for sports recovery, but research is scant. This study examined the effects of an ECP session upon neuromuscular function (vertical jump and torque/velocity characteristics), biochemical responses (creatine kinase, cortisol, testosterone, alpha-amylase and immunoglobulin-A), and muscle soreness (visual analogue scale) following high-intensity exercise. Twenty-one male team sport athletes (age: 21.6±3.4 yrs; height: 182.7±7.3 cm; body mass: 82.7±9.3 kg) recovered from the fatiguing exercise using either ECP or rest. Data collection was conducted at three separate time points: upon arrival (Pre), post-recovery (Post), and 24 h post-recovery (24hPost). Significant main effects for time were observed for increased torque/velocity slope and for decreased isometric extension peak torque (p<0.001). Significant main effects for time were observed for increased creatine kinase, testosterone, alpha-amylase, and muscle soreness (all p<0.001). Significant interaction effects were observed at post-testing following ECP: Cortisol release and the related decline in testosterone/cortisol ratio were attenuated, and immunoglobulin-A was increased following ECP in comparison to the control (all p<0.05). Following high-intensity exercise, ECP has potentially beneficial effects upon biomarkers of recovery, without affecting the neuromuscular function.

Changes in knee extension peak torque and body composition and their relationship with change in gait speed

BackgroundSlow gait speed is a powerful predictor of disability in activities of daily living and mortality. Muscle strength and body composition change over time, but their changes differ by sex. How these parameters jointly affect gait speed decline is unknown. Understanding this association could help develop and evaluate the sex‐specific effects of lifestyle interventions to delay gait speed decline in older adults. We assessed whether changes in strength (Δstrength), appendicular lean mass (ΔALM), and fat mass (Δfat) jointly relate to change in gait speed and whether the association differs by sex.MethodsThe analytic sample comprised 575 women and 539 men aged 22–95 years enrolled in the Baltimore Longitudinal Study of Aging. Mean follow‐up was 4.0 years. Measures included isometric knee extension strength, dual‐energy X‐ray absorptiometry‐assessed ALM and fat mass, and gait speed from the 400 m fast pace walk. Sex‐specific linear mixed models were adjusted for follow‐up time and baseline age, race, height, ALM, fat mass, peak torque, and gait speed. We also included second‐order interaction terms of the key predictive variables (e.g. Δstrength × ΔALM). To interpret the interactions, we estimated average gait declines using the 25th or 75th percentile of the two significant predictive variables and then assessed which condition relates to larger decline in gait speed.ResultsIn both sexes, independent of ΔALM and Δfat, larger decline in strength significantly related to larger decline in gait speed (P = 0.01 for both sexes). In men, interactions between Δstrength × ΔALM and Δfat by ΔALM were associated with change in gait speed; men with greater declines in both muscle strength and ALM or greater declines in both ALM and fat have steeper gait speed decline. In contrast, in women, the interaction between Δfat and ΔALM was associated with change in gait speed; women with an increase in fat mass combined with less decline in ALM have steeper gait speed decline.ConclusionsWhile change in strength affects change in gait speed in both sexes, the effects of body composition change differ by sex. Dual‐energy X‐ray absorptiometry‐based estimates of lean mass may be confounded by intramuscular fat. Future studies should examine sex‐specific combined effects of change in strength and body composition on mobility using multiple techniques to measure body composition. Intervention studies should consider testing sex‐specific interventions on body composition.

Is Femoral Version Associated with Changes in Hip Muscle Strength in Females with Symptomatic Femoroacetabular Impingement?

Objective The aim of the present study was to evaluate the association between femoral anteversion and hip muscle strength in subjects with femoroacetabular impingement syndrome. Method The femoral version angles described in the arthro-magnetic resonance images and isokinetic tests were retrospectively evaluated from July 2016 to December 2017. The inclusion criteria were: a) femoral version evaluated by the same radiologist; b) α angle ≥ 55°; and c) no limiting pain during the isokinetic test. Flexion/extension, abduction/adduction, and internal/external rotation peak torques were evaluated at 30° per second in 5 repetitions. The correlation between femoral version and muscle strength was evaluated by simple linear regression at a 5% significance level. Results A total of 37 females filled the inclusion criteria, and 51 symptomatic hips were evaluated. There was no correlation of the femoral anteversion in the flexion, extension, abduction, adduction, external rotation and internal rotation peak torques. Conclusion Femoral anteversion did not show a correlation with hip muscle strength in females with symptomatic femoroacetabular impingement.

Effect Of Ballet Dance On Knee Joints Muscle Strength Based On The Isokinetic Research

PURPOSE: Several researches have revealed that dance training increases muscle strength. By comparing the muscle strength of knee joints of ordinary college students with ballet dance students', the differences between the two groups were analyzed and the influence of dance on muscle strength was explained. METHODS: 48 healthy college students volunteered to participate in the study. Experimental group consisted of 24 Ballet students (12 male, 21.5±0.9years; 12 female, 20.9±1.8years); control group consisted of 24 non-dance students (12male, 20.7±0.9years, 12 female, 20.6±0.8years). German ISOMED2000 Isokinetic test device was used to test the knee joints strength of all participants, with the concentric contraction test going first and then following the eccentric contraction test , with the testing angular of 60°/s,180°/s .The test variables include peak torque,relative peak torque and the peak torque ratio of flexion and extension. RESULTS: The result showed that the female and male Ballet students have significantly higher peak torque (N·m )and relative peak torque (Nm/Kg) at all angular of knee flexion and extension than non-dance students (All peak torque flexion at 60°/s and 180°/s: 81.805±10.84 vs. 58.725±7.34 and 68.055±9.22 vs.46.875±8.78; both p<0.01. All peak torque extension at 60°/s and 180°/s: 178.335±25.88 vs. 124.2±19.54 and 128.465±14.96 vs. 92.505±16.41; both p<0.01. All relative peak torque flexion at 60°/s and 180°/s:1.29±0.14 vs. 1.02±0.14 and 1.08±0.14 vs.0.81±0.13;both p<0.01. All relative peak torque extension at 60°/s and 180°/s :2.84±0.43 vs.2.17±0.38 and 2.04 ±0.25 vs.1.61±0.28; both p<0.01.).However, there is no significant difference in peak torque ratio of flexion and extension between two groups (P>0.05). CONCLUSIONS: The results indicated that long-term ballet training can obviously improve the control strength and outbreak power of knee flexion and extension. Ballet training leads to a balanced effect impact on hamstring and quadriceps, which helps to avoid knee injuries and improve the dance movements. Acknowledgements: This work was supported by Beijing philosophy and social science foundation research (Grants No.14JDWYB011).

Adaptations of short-term high-velocity isokinetic training vs. short-term plyometric training on vertical jump and isokinetic performance in physically active people

BACKGROUND: The effect of short-term interventions using high-velocity isokinetic or plyometric exercises has not been thoroughly investigated. OBJECTIVE: The aim of this study was to compare the effect of a lower body 3-week protocol using an isokinetic or a plyometric exercise program on strength and jump performance. METHODS: Thirty-six non-trained men were randomly allocated to the following three groups: (i) Isokinetic only (ISO, n= 12), performed 6 sets of 10 repetitions of concentric leg extension and flexion at 300∘⋅s-1 using an isokinetic dynamometer (Biodex-System-3); (ii) Plyometric only (PLY, n= 12) performed 6 sets of 10 repetitions of vertical jump; and (iii) Control, non-training group (n= 12). A 3-week training program involving two weekly workout sessions was implemented. Pre and post intervention measurements of knee extensor and flexor maximal peak torque, total work and average power at 300∘⋅s-1 and vertical jump performance were determined. RESULTS: Compared to baseline ISO significantly (p< 0.05) increased knee extension peak torque and average power. No other significant differences were observed at post-intervention or between groups. CONCLUSIONS: Compared to performing plyometric exercise alone, a 3-week intervention using only isokinetic training enhanced knee extensors strength. A more effective and specific neural adaptations driven by the isokinetic protocol over a short period of time could explain the observed responses.

Twenty-Four Months' Resistance and Endurance Training Improves Muscle Size and Physical Functions but Not Muscle Quality in Older Adults Requiring Long-Term Care.

To assess the effects of 24 months training on muscle quality, size, strength, and gait abilities in older adults who need long-term care. Non-randomized controlled trial Setting: Kawai Rehabilitation Center and Kajinoki Medical Clinic. Ten older participants who needed long-term care (age, 76.7 ± 5.6 years) were participated as training group (Tr-group) and 10 older men and women who did not require long-term care (age, 72.9 ± 6.6 years) comprised the control group (Cont-group). Tr-group performed resistive and endurance exercises once or twice a week for 24 months. Using ultrasound images, echo intensity (EI) and muscle thickness were measured in the rectus femoris and biceps femoris as an index of muscle quality and size. Physical performance was measured before and after the training; performance parameters included knee extension peak torque, 5-m normal and maximal walk test, sit-to-stand and timed up and go test. After the training, there was no change in EI, while BF thickness was increased (pre; 1.82 ± 0.29 cm, 24 months; 2.14 ± 0.23 cm, p < 0.05) in Tr-group. Walk-related performances were improved after the training in Tr-group (i.e. 5-m walk test and timed up and go test). The percent change of knee extension peak torque explained the percent change of EI in the rectus femoris (regression coefficient = 1.24, R = 0.91, adjusted R2 = 0.82, p < 0.001). Twenty-four months' training induced muscle hypertrophy and improved physical functions. Increased muscle quality in the rectus femoris could be a key to improved knee extension peak torque, with the potential to eventually reduce the need for long-term care in older individuals.

Blood Flow Restriction During Futsal Training Increases Muscle Activation and Strength

The aim of this study was to investigate the effect of leg blood flow restriction (BFR) applied during a 3-a-side futsal game on strength-related parameters. Twelve male futsal players were randomly assigned into two groups (n = 6 for each group) during 10 training sessions either with or without leg BFR. Prior to and post-training sessions, participants completed a series of tests to assess anabolic hormones and leg strength. Pneumatic cuffs were initially inflated to 110% of leg systolic blood pressure and further increased by 10% after every two completed sessions. In comparison with baseline, the resting post-training levels of myostatin (p = 0.002) and IGF-1/MSTN ratio (p = 0.006) in the BFR group changed, whereas no change in the acute level of IGF-1 and myostatin after exercise was observed. Peak torque of knee extension and flexion increased in both groups (p < 0.05). A trend of increased neural activation of all heads of the quadriceps was observed in both groups, however, it was statistically significant only for rectus femoris in BFR (p = 0.02). These findings indicated that the addition of BFR to normal futsal training might induce greater neuromuscular benefits by increasing muscle activation and augmenting the hormonal response.

Cigarette Smoking Is Associated With Lower Quadriceps Cross-sectional Area and Attenuation in Older Adults.

In addition to well-established links with cardiovascular and respiratory diseases, cigarette smoking may affect skeletal muscle; however, associations with quadriceps atrophy, density, and function are unknown. This study explored the associations of current and former smoking with quadriceps muscle area and attenuation as well as muscle force (assessed as knee extension peak torque) and rate of torque development-a measure of muscle power in older adults. Data from 4469 older adults, aged 66-95 years at baseline in the Age, Gene/Environment Susceptibility-Reykjavik Study with measurements of thigh computed tomography, isometric knee extension testing, self-reported smoking history, and potential covariates were analyzed. Sex differences were observed in these data; therefore, our final analyses are stratified by sex. In men, both former smokers and current smokers had lower muscle area (with β= -0.10, 95% confidence interval [CI] = -0.17 to -0.03 and β = -0.19, 95% CI = -0.33 to -0.05, respectively) and lower muscle attenuation (ie, higher fat infiltration, β = -0.08, 95% CI = -0.16 to -0.01 and β = -0.17, 95% CI = -0.34 to -0.01, respectively) when compared with never smokers. Smoking status was not associated with male peak torque or rate of torque development. In women, current smoking was associated with lower muscle attenuation (β = -0.24, 95% CI = -0.34 to -0.13) compared to never smoking. Among female smokers (current and former), muscle attenuation and peak torque were lower with increasing pack-years. Results suggest that cigarette smoking is related to multiple muscle properties at older age and that these relationships may be different among men and women. This article presents novel data, as it examined for the first time the relationship between smoking and computed tomography-derived quadriceps muscle size (cross-sectional area) and attenuation. This study suggests that current cigarette smoking is related to higher muscle fat infiltration, which may have significant health implications for the older population, because of its known association with poor physical function, falls, and hip fractures.

Caffeinated Gel Ingestion Enhances Jump Performance, Muscle Strength, and Power in Trained Men.

We aimed to explore the effects of caffeinated gel ingestion on neuromuscular performance in resistance-trained men. The participants (n = 17; mean ± standard deviation (SD): age 23 ± 2 years, height 183 ± 5 cm, body mass 83 ± 11 kg) completed two testing conditions that involved ingesting a caffeinated gel (300 mg of caffeine) or placebo. The testing outcomes included: (1) vertical jump height in the squat jump (SJ) and countermovement jump (CMJ); (2) knee extension and flexion peak torque and average power at angular velocities of 60°·s−1 and 180°·s−1; (3) barbell velocity in the bench press with loads corresponding to 50%, 75%, and 90% of one-repetition maximum (1RM); and (4) peak power output in a test on a rowing ergometer. Compared to the placebo, caffeine improved: (1) SJ (p = 0.039; Cohen’s d effect size (d) = 0.18; +2.9%) and CMJ height (p = 0.011; d = 0.18; +3.3%); (2) peak torque and average power in the knee extensors at both angular velocities (d ranged from 0.21 to 0.37; percent change from +3.5% to +6.9%), peak torque (p = 0.034; d = 0.24; +4.6%), and average power (p = 0.015; d = 0.32; +6.7%) at 60°·s−1 in the knee flexors; (3) barbell velocity at 50% 1RM (p = 0.021; d = 0.33; +3.5%), 75% 1RM (p < 0.001; d = 0.42; +5.4%), and 90% 1RM (p < 0.001; d = 0.59, +12.0%). We conclude that the ingestion of caffeinated gels may acutely improve vertical jump performance, strength, and power in resistance-trained men.

Changes in Physical Fitness After 12 Weeks of Structured Concurrent Exercise Training, High Intensity Interval Training, or Whole-Body Electromyostimulation Training in Sedentary Middle-Aged Adults: A Randomized Controlled Trial.

This study aimed to investigate the influence of different exercise training modalities [(i) a concurrent training based on physical activity recommendation from the World Health Organization group (PAR group), (ii) a high intensity interval training group (HIIT group), and (iii) a high intensity interval training adding whole-body electromyostimulation group (WB-EMS group)] on physical fitness in sedentary middle-aged adults. A total of 89 (52.7% women) middle-aged sedentary adults (53.7 ± 5.1 years old) were enrolled in the FIT-AGING study. Cardiorespiratory fitness was determined by a maximum treadmill test using indirect calorimetry. Lower, upper, and core body muscular strength were assessed by an isokinetic strength test, by the handgrip strength test, and by several core strength endurance tests, respectively. All the exercise types induced similar increases on cardiorespiratory fitness (Δ VO2max ≥ 11%, Δ maximal heart rate ≥ 8%, and Δ total test duration ≥ 14%; all P ≤ 0.034), as well as on muscular strength (Δ extension and flexion peak torque ≥ 10%, Δ total hand grip ≥ 3%, Δ core strength endurance tests ≥ 20%; all P ≤ 0.050) compared with a control group. In conclusion, our results suggest that a 12-week structured exercise intervention improves physical fitness regardless of the training program in sedentary middle-aged adults. Despite slightly greater improvements in some physical fitness variables, the changes observed in the WB-EMS group were not superior to the other exercise programs.

The Relation of Inflammaging With Skeletal Muscle Properties in Elderly Men.

Aging is associated with a progressive decline of muscle mass and/or the qualitative impairment of the muscle tissue. There is growing evidence of the prominent role of low-grade chronic inflammation in age-related changes in the neuromuscular system. The purpose of the study was to identify the inflammatory mediators responsible for deficit in functional fitness and to explain whether inflammation is related to changes in body composition and the decline of muscle strength in older men. Thirty-three old-aged males (73.5 ± 6.3 years) and twenty young-aged males (21.2 ± 1.3 years) participated in the study. The body composition (bioelectrical impedance analysis), functional capacity (6-min walking test) and knee extension strength (isokinetic test) were estimated. In serum, circulating inflammatory markers H2O2, IL-1β, TNFα, and hsCRP as well as growth factors IGF-I and PDGFBB concentrations were determined (immunoenzymatic methods). The concentrations of H2O2, IL-1β, TNFα, and hsCRP were significantly higher in older than young men. The growth factors IGF-I and PDGFBB were twofold lower and related to high levels of IL-1β and TNFα in the elderly. The changes in cytokines and growth factors levels were correlated with age and peak torque (TQ at 60°/s and 180°/s) in the knee extension. The result of the 6-min walking test was inversely correlated with fat mass index (FMI, r = −.983; p < .001). The generation of inflammatory mediators in older men was related to changes in body composition, maximum strength muscle, and age-related changes in skeletal muscle properties responsible for deficit in functional fitness.

The relationship between peripheral muscle strength and respiratory function and respiratory muscle strength in athletes.

The aim of this study is to determine the relationship between peripheral muscle strength, respiratory function and respiratory muscle strength in athletes. The study included a total of 150 elite athletes (judo, rowing, gymnastics) (age, 16.94±2.37 years; length, 167.70±12.23 cm; body weight, 62.87±17.33 kg; body mass index, 21.95±2.92 kg/m2). Isomed 2000 isokinetic dynamometer was used to assess peripheral muscle strength. The strength of the dominant side knee flexor and extensor muscles was evaluated at 60°/sec and 180°/sec. At the end of the evaluation; knee flexion and extension peak torque (PT) values and flexion and extension PT values rates were obtained at 60°/sec and 180°/sec. Respiratory function and respiratory muscle strength of the athletes were evaluated using a digital spirometer. To assess respiratory function, forced vital capacity maneuver and maximal minute ventilation test; to assess the strength of the respiratory muscles, maximum inspiratory pressure and maximal expiratory pressure tests were performed. There was a strong relationship between muscle strength of knee flex-or and extensor muscles and respiratory function (r=−0.268/0.813, P<0.05). There was a strong moderate correlation between knee flexor and extensor muscle strength and all parameters of respiratory muscle strength (r=0.206/0.411, P<0.05). The knee flexor and extensor muscle strength, respiratory function and respiratory muscle strength develops parallel to each other and the codevelopment of these parameters together with special exercises to increase respiratory muscle strength will improve the performance of the athletes.

The relationship between peripheral muscle strength and respiratory function and respiratory muscle strength in athletes

The aim of this study is to determine the relationship between peripheral muscle strength, respiratory function and respiratory muscle strength in athletes. The study included a total of 150 elite athletes (judo, rowing, gymnastics) (age, 16.94±2.37 years; length, 167.70±12.23 cm; body weight, 62.87±17.33 kg; body mass index, 21.95±2.92 kg/m2). Isomed 2000 isokinetic dynamometer was used to assess peripheral muscle strength. The strength of the dominant side knee flexor and extensor muscles was evaluated at 60°/sec and 180°/sec. At the end of the evaluation; knee flexion and extension peak torque (PT) values and flexion and extension PT values rates were obtained at 60°/sec and 180°/sec. Respiratory function and respiratory muscle strength of the athletes were evaluated using a digital spirometer. To assess respiratory function, forced vital capacity maneuver and maximal minute ventilation test; to assess the strength of the respiratory muscles, maximum inspiratory pressure and maximal expiratory pressure tests were performed. There was a strong relationship between muscle strength of knee flex-or and extensor muscles and respiratory function (r=−0.268/0.813, P<0.05). There was a strong moderate correlation between knee flexor and extensor muscle strength and all parameters of respiratory muscle strength (r=0.206/0.411, P<0.05). The knee flexor and extensor muscle strength, respiratory function and respiratory muscle strength develops parallel to each other and the codevelopment of these parameters together with special exercises to increase respiratory muscle strength will improve the performance of the athletes. Keywords: Athletes, Muscle strength, Respiratory muscle, Respiratory function

Association of physical activity and fitness with S-Klotho plasma levels in middle-aged sedentary adults: The FIT-AGEING study

ObjectivesTo determine the association between physical activity and physical fitness levels (i.e. cardiorespiratory fitness and muscular strength) and the shed form of the α-Klotho gene (S-Klotho plasma levels) in middle-aged sedentary adults. Study design and main outcome measuresA total of 74 middle-aged sedentary adults (52.7% women; 53.7 ± 5.1 years old) were enrolled in the FIT-AGEING study. Physical activity and sedentary time were assessed with a wrist-worn accelerometer. Maximal oxygen uptake (VO2max) was determined by a maximum treadmill test using indirect calorimetry. Lower- and upper-body muscular strength were assessed by an isokinetic strength test and by the hand grip strength test, respectively. The S-Klotho plasma levels were measured in the EDTA plasma using a solid-phase sandwich enzyme-linked immunosorbent assay. ResultsBased on the principal-component analysis, overall physical activity, moderate and vigorous physical activity levels, and sedentary time (as outcomes included in the ‘sedentary time and physical activity’ category) explained a total of 17.5% of the cumulative variance in S-Klotho plasma levels, while extension peak torque, hand grip strength, and maximal oxygen uptake (as outcomes included in the ‘physical fitness’ category) explained a total of 15.5% of the cumulative variance in S-Klotho plasma levels. Based on the loading of variables in these 2 categories, the percentage of the cumulative variance in S-Klotho plasma level explained was 28.9%s; this reached 33.0% of cumulative variance when sex was included in the model. ConclusionsIn summary, our results indicate that physical activity and physical fitness levels are associated with S-Klotho plasma levels in middle-aged sedentary adults. Therefore, the S-Klotho protein could be a key factor in the relationship between physical activity and physical fitness and health improvements during the ageing process.

Adductor Canal Nerve Versus Femoral Nerve Blockade for Pain Control and Quadriceps Function Following Anterior Cruciate Ligament Reconstruction With Patellar Tendon Autograft: A Prospective Randomized Trial

To compare femoral nerve blockade (FNB) versus adductor canal nerve blockade (ACB) for postoperative pain control and quadriceps muscle function in patients undergoing anterior cruciate ligament (ACL) reconstruction with patellar tendon autograft. A randomized therapeutic trial of 90 patients undergoing ACL reconstruction with patellar tendon autograft was conducted comparing ACB versus FNB at 24hours, 2 and 4 weeks, and 6months postsurgery. Early outcome measures included average pain score and morphine equivalent units (milligrams) consumed, quadriceps surface electromyography, straight leg raise, and ability to ambulate without assistive devices. The 6-month outcome measures included knee range of motion (ROM), isokinetic knee extension peak torque, single-leg squat, and single-leg hop performance. Complications were recorded throughout the study for the development of anterior knee pain, knee extension ROM loss, deep vein thrombosis, and graft failure. Mixed-model analysis of variance and Mann-Whitney U tests were performed using an alpha of .05. Quadriceps surface electromyography deficits were higher for FNB at 24hours (P < .001) and 2weeks (P < .001) when compared with the ACB group. There were no between-groups difference for subjective pain (P= .793) or morphine consumption (P= .358) within the first 24hours of surgery. A higher percentage of patients in the ACB group met the full ambulation criteria at 4weeks compared with the FNB group (100% vs 84.2%, P < .001). No between-group differences were observed at 6months; however, the rate of knee extension ROM loss was higher for the FNB group versus the ACB group (21.1% vs 5.0%, P= .026), respectively. ACB was as effective as FNB at providing pain control while eliciting fewer quadriceps muscle activation deficits and fewer postoperative complications. Based on previous evidence and the results of this study, we recommend the use of ACB over FNB for theanalgesic management of patients undergoing ACL reconstruction with patellar tendon autograft. Level I, prospective randomized controlled trial.

Proximal, Distal, and Contralateral Effects of Blood Flow Restriction Training on the Lower Extremities: A Randomized Controlled Trial.

Background:Blood flow restriction (BFR) training involves low-weight exercises performed under vascular occlusion via an inflatable cuff. For patients who cannot tolerate high-load exercises, BFR training reportedly provides the benefits of high-load regimens, with the advantage of less tissue and joint stress.Hypothesis:Low-load BFR training is safe and efficacious for strengthening muscle groups proximal, distal, and contralateral to tourniquet placement in the lower extremities.Study Design:Randomized controlled trial.Level of Evidence:Level 1.Methods:This was a randomized controlled trial of healthy participants completing a standardized 6-week course of BFR training. Patients were randomized to BFR training on 1 extremity or to a control group. Patients were excluded for cardiac, pulmonary, or hematologic disease; pregnancy; or previous surgery in the extremity. Data collected at baseline and completion included limb circumferences and strength testing.Results:The protocol was completed by 26 patients, providing 16 BFR and 10 control patients (mean patient age, 27 years; 62% female). A statistically greater increase in strength was seen proximal and distal to the BFR tourniquet when compared with both the nontourniquet extremity and the control group (P < 0.05). Approximately twice the improvement was seen in the BFR group compared with controls. Isokinetic testing showed greater increases in knee extension peak torque (3% vs 11%), total work (6% vs 15%), and average power (4% vs 12%) for the BFR group (P < 0.04). Limb circumference significantly increased in both the thigh (0.8% vs 3.5%) and the leg (0.4% vs 2.8%) compared with the control group (P < 0.01). Additionally, a significant increase occurred in thigh girth (0.8% vs 2.3%) and knee extension strength (3% vs 8%) in the nontourniquet BFR extremity compared with the control group (P < 0.05). There were no reported adverse events.Conclusion:Low-load BFR training led to a greater increase in muscle strength and limb circumference. BFR training had similar strengthening effects on both proximal and distal muscle groups. Gains in the contralateral extremity may corroborate a systemic or crossover effect.Clinical Relevance:BFR training strengthens muscle groups proximal, distal, and contralateral to cuff placement. Patients undergoing therapy for various orthopaedic conditions may benefit from low-load BFR training with the advantage of less tissue stress.

The association between physical activity, sedentary behavior and the occurrence of falls in asymptomatic adults over 40 years old

Abstract Introduction: Sedentary behavior (SB) has been described as an independent risk factor for health, regardless of the recommended amount of moderate-to-vigorous physical activity (MVPA). However, SB and MVPA as predictors of falls have been poorly investigated. Objective: To compare the associations between SB and MVPA and the occurrence of falls in middle-aged and older adults. Method: The participants wore a triaxial accelerometer over the dominant hip for seven days to measure SB and MVPA. The occurrence of falls and cardiovascular risk factors were assessed by self-report. Isokinetic peak torque (PT) of knee extension, peak oxygen uptake (V’O2) in a ramp treadmill protocol, and lean (LBM) body mass and body fat (BFM) (bioelectrical impedance) were also assessed. The critical roles of SB and MVPA on the occurrence of falls were compared by multiple logistic regression adjusted for age, sex, cardiovascular risk factors, LBM, peak V’O2, and PT of knee extension. Results: 379 participants were evaluated, aged 40-80 years. Forty-eight participants reported at least one fall in the previous 12 months (14.5%). Fallers presented lower SB and higher MVPA. They were predominantly women and older adults with lower physical fitness. After multivariate analysis, MVPA, but not SB, was selected as an independent predictor of falls, increasing the odds ratio of having a fall (1.184, 95% confidence interval, 1.016 - 1.378). Conclusion: Episodes of falls in predominantly middle-aged and women subjects were associated with a higher amount of MVPA, not the opposite, indicating an adverse effect of MVPA in these subjects.

The relationship between isokinetic knee flexion and extension muscle strength, jump performance, dynamic balance and injury risk in female volleyball players

The relationship between balance, knee muscle strength, jump height and risk of injury has not been clearly stated in female volleyball athletes. The study was to determine whether a correlation exists between knee joint isokinetic muscle strength, risk of injury, balance and jump height in female volleyball athletes. Twenty-two female volleyball athletes were involved into the study. Knee muscle strength were evaluated with the Biodex 3 ® isokinetic dynamometer. Jump performances were evaluated with the countermovement (CMJ) jump test using the Vert Jump ® Motion Sensitive Sensor. The injury risk for all players were evaluated by the Functional Movement Screen (FMS ® ). Balance measurements were performed with a dynamometer Biodex Systems 3 ® device. There was a significant relationship between CMJ height, knee flexion and extension peak torque and H:Q ratio values at two angular velocities, dynamic balance and total FMS ® scores ( p .05). We suggest that all clinicians and coaches involved in the protective and preventive rehabilitation phase evaluate these parameters and plan their training programs in line with the results obtained in increasing both individual and team performance of athletes.

SHOULDER ISOKINETIC PERFORMANCE IN HEALTHY PROFESSIONAL JUDO ATHLETES: NORMATIVE DATA.

ABSTRACTObjective:To evaluate normative data of shoulder isokinetic strength in healthy professional judo athletes.Methods:Cross-sectional study with 20 professional male and female athletes (10 female), evaluated with an isokinetic dynamometer. The strength assessment was carried out in external and internal rotation, flexion, extension, adduction and abduction. All data collected on muscle torque were normalized with body mass index.Results:Athletes demonstrated higher peak torque and joint work in shoulder adduction, abduction, flexion, and extension for the dominant limb compared to the non-dominant limb (p <0.05), with most of these deficits below 10%. Shoulder internal/external rotation ratios for male and female athletes had no significant differences between dominant and non-dominant sides, demonstrating values at 60°/s of 49.4 ± 7.2 on the dominant side of males and 49.1 ± 4.9 for females.Conclusion:The normative data are described to assist during treatment, return to sport and injury prevention. Level of evidence IV, cross-sectional study.

Side-to-side asymmetry in lower limb strength and hamstring-quadriceps strength ratio among collegiate American football players.

[Purpose] The present study aimed to investigate the lower limbs injury risk factors that are based on conventional Hamstring to Quadriceps ratio and limb asymmetry index in varsity American football players. [Participants and Methods] Twenty-six varsity American football players aged 19–27 years and with 2.31 ± 1.29 years of American football experience from Dogu Akdeniz University volunteered to undergo measurements of average peak torque for isokinetic flexion and extension of dominant limb and non-dominant limb at 60°·s−1 and 300°·s−1. Hamstring to Quadriceps ratio and limb asymmetry index were also calculated for Hamstring and Quadriceps muscles. [Results] Statistical analysis revealed that dominant Quadriceps is stronger than non-dominant Quadriceps at 60°·s−1 speed. No statistical difference was found between dominant and non-dominant Hamstring peak torque at 60°·s−1 . Hamstring to Quadriceps ratio determined as normal both for 60°·s−1 and 300°·s−1according to the currently reported cut off value (H:Q ratio >60). Hamstring and Quadriceps limb asymmetry index also determined as normal (cut off value for LSI 10%) at 60°·s−1. However, for both Hamstring and Quadriceps, side- to- side strength asymmetry at 300°·s−1 was observed. [Conclusion] To prevent possible lower limb injury and to increase performance, varsity American football players who are actively training and competing might consider taking strength asymmetry into account to tailor their strength training program accordingly.