Relative Peak Torque Research Articles

COMPARISON OF DOMINANT AND NONDOMINANT LEG STRENGTH AND HAMSTRING: QUADRICEPS RATIO IN PROFESSIONAL BASKETBALL PLAYERS

The literature has revealed that knee injuries are the most common injury among basketball players. The strength ratios dominant/non-dominant and posterior-anterior around the knee joint are used to evaluate strength balances. But there has been far less research published about strength evaluation in professional-level basketball. The objectives of the present study were: (i) to compare hamstring and quadriceps muscles’ strength values during concentric knee extension and flexion at different angular velocities at professional level basketballers, (ii) to determine dominant and non-dominant strength values during these contractions. 13 professional male basketball athletes voluntarily participated in the study. The leg strength was evaluated with an isokinetic dynamometer at 240- 180-120-600 /s angular velocities. The hamstring and quadriceps unilateral peak torque ratio (H/Q) and dominant non-dominant strength ratio were calculated. The independent t-test was computed to bilateral and unilateral strength outputs. There was no statistically significant difference between dominant and non-dominant strength values at peak torque, normalized peak torque, and H/Q at all angular velocities. Relative peak torque outputs in both legs were similar at all angular velocities. Also, the H/Q was calculated as ≥0.60 in all velocities. The results of this study suggest there were not any significant differences in the unilateral and bilateral evaluations of professional basketballers. These nonsignificant differences could be related to the necessity to maintain similar strength of two legs.

Resistance Training Enhances Muscle Function and Hemorheological Properties in Middle‐aged Obese Women

PurposeThe present study investigated the effects of resistance training for 12‐week on body composition, blood pressure, blood lipid level, cross sectional area (CSA) of muscles, isokinetic muscle function, and hemorheological properties in middle‐aged obese women.MethodsThirty obese women (50.79 ± 5.80 years), with no history of any injuries to the musculoskeletal system and no participating any regular exercise program, were included in the present study. All participants were randomly assigned to a control group (CON, n = 15) or an experimental group (EXP, n = 15); but two participants in the CON voluntarily withdrew because of personal reasons, and thirteen participants in the CON finally participated. The EXP underwent resistance training program composed of warm‐up, main resistance exercise (bench press, preacher bench biceps curl, barbell rowing, dumbbell shoulder press, dead lift, barbell squat, seated leg extension, and lying leg curl), and cool‐down. Main resistance exercise was consisted of three sets of 8–10 repetitions (reps) performed with 80% of 1‐RM. The training frequency was 80 min, 3 days per week for 12 weeks. The CON maintained their daily lifestyle without training. All participants underwent body composition (weight, body mass index, lean body mass, fat mass, and %body fat), blood pressure (systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse pressure), blood lipid level (triglyceride, total cholesterol, high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol), cross sectional area (CSA) of muscles (quadriceps CSA, hamstring CSA, and total thigh muscle CSA), isokinetic muscle function (peak torque, relative peak torque, mean power, and total work in quadriceps femoris and hamstrings), and hemorheological properties (erythrocyte deformability and erythrocyte aggregation) were measured before and after 12‐week of training.ResultsThe EXP showed a significant decrease in fat mass (p = .018) via 12‐week of resistance training. Also, the EXP yielded more significant improved muscle function including peak torque (p < .001), relative peak torque (p < .001), and total work (p = .001) in quadriceps femoris and total work (p = .018) in hamstrings. Regarding hemorheological properties, the EXP showed a significant increase in erythrocyte deformability (p = .001) via 12‐week of resistance training. However, there was no significant change in blood pressure and muscle CSA parameters via 12‐weeks of resistance training.ConclusionThe present study verified our resistance training program shows greater muscle strength and endurance, decreasing fat mass, and improving hemorheological properties such as erythrocyte deformability.

Study on the correlation between lower limb joint muscle strength and balance ability among female college students in soccer

Abstract To study the correlation between lower limb joint muscle strength at different angular velocities and dynamic balance among college students in soccer. Methods: 30 college students from Zunyi Medical University had a regular football training more than 16 weeks. The ISO-MED2000 was used to test the peak flexion and extension torque of the hip, knee and ankle at different angular velocities, and the Y-Balance Test was used to test the dynamic balance of lower extremities. Results: The relative peak of hip flexion and extension was associated well with balance ability at an angular velocity of 180°/ s; the relative peak torque of flexion and extension of the knee was well correlated with the balance ability at 30°/ s and 180°/ s (P>0.01); the ankle flexion was well correlated with balance ability at 30°/ s and 90°/ s(P>0.01). Conclusions: Muscular strength of lower extremities play different effects on dynamic balance ability at different velocity.

The Muscle Strength of the Knee Joint after ACL Reconstruction Depends on the Number and Frequency of Supervised Physiotherapy Visits.

The aim of this study in anterior cruciate ligament reconstruction (ACLR) patients was to assess the effect of six months of supervised physiotherapy with a higher number of visits (SPHNV) compared to supervised physiotherapy with a lower number of visits (SPLNV) on the maximal peak torque (PT) and isometric torque (IT) of values obtained for hamstring (H) and quadriceps (Q) muscles of the knee joints under isokinetic and isometric conditions. Hypothesis: SPHNV improves IT and PT more than SPLNV. Group I had ACLR with a higher number of visits (n = 20), Group II had ACLR with a lower number of visits (n = 20), and Group III served as the control (n = 20). In Groups I and II, IT values were measured for quadriceps and hamstring muscles of the knee joints in the 13th and 24th weeks and for PT in the 18th and 24th weeks after ACLR (60 and 180 °/s). In group III, the measurements were taken once. The isometric torque and isokinetic peak torque values were measured in N*m and they were normalized to body mass as relative IT (RIT) and relative PT (RPT) were expressed in N*m/kg. Results: In both ACLR groups, the RIT and RPT values obtained from the operated knee joints significantly increased in the 24 weeks following ACLR compared to the uninvolved side. Group II had significantly lower RIT and RPT values for quadriceps and hamstring muscles of the operated limbs compared with the uninvolved limbs (p = 0.008, p = 0.001). In group I, the larger number of visits positively correlated with the higher PT for quadriceps and hamstring muscles of the operated and uninvolved knees (from r = 0.506; p = 0.023 too r = 0.566; p = 0.009), respectively. Six months of SPHNV positively correlated with and improved the IT and PT values in patients after ACLR much more significantly than six months of SPLNV.

Responses to a combined dynamic stretching and antagonist static stretching warm-up protocol on isokinetic leg extension performance

ABSTRACT Antagonist static-stretching and dynamic-stretching are both effective at improving muscular performance. The purpose of this study was to investigate responses to a dynamic stretching warm-up protocol, a static-stretching warm-up protocol and a combined dynamic-stretching and antagonist static stretching warm-up protocol on isokinetic leg extension performance. Twelve participants completed a baseline (PRE) isokinetic knee-extension test at 60°.s−1 and 300°.s−1, following a 5 min warm-up on a cycle ergometer. Subsequently, participants completed the following warm-up protocols randomly over a three-week period: dynamic-stretching (DS); antagonist muscle static-stretching (AMSS) and dynamic followed by antagonist muscle static-stretching (DS-AMSS). A repeated measures analysis of variance (ANOVA) was conducted to determine where significant differences existed for peak torque, total work, average power, time-to-peak-torque and relative peak torque between warm-up protocols. DS-AMSS facilitated a significantly higher peak torque and total work compared to PRE, DS and AMSS at 60°.s−1 and 300°.s−1 P < 0.05, respectively). DS-AMSS caused significantly greater relative peak torque than PRE for 60°.s−1 and 300°.s−1 (P < 0.05). DS-AMSS resulted in significantly reduced time-to-peak-torque and increased average power at 60°.s−1 compared to PRE, DS and AMSS (P < 0.05). DS-AMSS and AMSS resulted in a significant reduction in time-to-peak-torque and increased average power compared to the PRE and DS (P < 0.05) at 300°.s−1.

CHANGES IN THE FLEXOR AND EXTENSOR MUSCLES AT DIFFERENT SPEEDS

ABSTRACT Introduction: Centrifugal strength is an important element for strength quality. Developing muscle centrifugal strength can effectively increase the stability of lower limbs and reduce the risk of injury. Objective: To explore the characteristics of contractile force of flexor ahods in strength training and rehabilitation training, and the extensor muscles of the knee joint in athletes with different speeds of centripetal force. Methods: The knee joint muscle group of 8 first-level male high jumpers and 8 second-level male high jumpers were tested by isokinetic centrifugal contraction; the angular test velocity was 60 °/s, 120 °/s, 240 °/s, and the indexes included peak torque, relative peak torque (peak torque/body weight), and the peak torque flexural extension ratio. Results: With the centrifugal contraction of the knee joint muscle group (P &lt; 0.05), the second-level high jumpers should increase the ability of the knee flexor muscle group of the take-off leg. In the case of constant velocity centrifugal contraction (P &lt; 0.01), taking off time must be reduced, that is, taking off speed must be accelerated. Conclusions: The difference in the knee joint muscle isokinetic test results is one of the reasons for the difference in knee joint flexor and extensor muscle contractility under the different speed forces of high jumpers. Level of evidence II; Therapeutic studies - investigation of treatment results.

Benefit of the Early Open Kinetic Chain on the Quadriceps Strength after Anterior Cruciate Ligament Reconstruction in Male Soccer Players in a Context of Return to Running

Background: The objective of this study is to determine whether the early association of the open kinetic chain (OKC) and the closed kinetic chain (CKC) allows an improvement in the strength and functional qualities of the quadriceps in the context of soccer rehabilitation after anterior cruciate ligament reconstruction.Materials: A collection of prospective data on two groups of 15 subjects who all suffered an after anterior cruciate ligament (ACL). Each subject is assigned to a group according to the type of rehabilitation they have undergone within the center, with only CKC rehabilitation and mixed OKC and CKC rehabilitation. The protocols were introduced four weeks after ACL reconstruction. The measurements were carried out at three months on an isokinetic dynamometer to measure the peak torque (PT) and to be able to determine limb symmetry index (LSI) and the PT concerning the body weight, the relative peak torque (PT/WB).Results: After testing the LSI and the PT/WB between the two groups, there was a significant difference (p &lt;0.05) between the LSI of the two groups and a very significant difference between the PT/WB (r=0.817; p&lt;0.001). We have also shown a significant positive correlation between these two parameters.Conclusion: The study suggests an interest in the early association of OKC and CKC in correcting quadriceps strength deficits and improving its functional quality after ACL reconstruction.

Isokinetic Muscle Strength and Postural Sway of Recreationally Active Older Adults vs. Master Road Runners.

Trunk muscle strength and control is an important prerequisite for everyday activities among elderly people decreasing the predisposition to falls. High levels of physical exercise performed by older athletes could offer benefits to core/trunk muscle strength and postural control compared with recreational physical activities and among elderly people with lower levels of physical activity. The present study aimed to compare trunk muscle strength and postural control of older running athletes vs. older physically active adults. Participants were master road runners (RUN, n = 15, six women, 64.3 ± 3.6 years) and physically active elderly (control group, CON, n = 15, six women, 65.4 ± 5.0 years) people that were submitted to the evaluations: esthesiometer, posturography (force plate), and isokinetic test (Biodex dynamometer) of trunk muscle extension and flexion. RUN presented higher values for relative peak torque of trunk extensor muscles at 60°/s (p = 0.046) and 180°/s (p = 0.007) and relative average power during trunk extension at 60°/s (p = 0.008) and 180°/s (p = 0.004) compared to CON. CON had a higher medial-lateral oscillation speed of the center of pressure in the stable condition with eyes closed (p = 0.004) compared to RUN. RUN presented higher isokinetic torque of extensor trunk muscles and better postural control than CON. This supposedly could help with postural control and balance and contribute to the prevention of falls among the elderly. The practice of running systematically by master athletes may partially explained our findings.

Sex Differences in Lower Limb Proprioception and Mechanical Function Among Healthy Adults.

Twenty-four healthy adults, including 12 females and 12 males, participated in the study. Each female participant completed three trials in three different phases of one menstrual cycle, which included follicular, ovulatory, and luteal phases. The study aimed to investigate whether there is any difference in joint kinetic sense, neuromuscular coordination, and isokinetic muscle strength (a)between healthy males and females at different phases of the menstrual cycle and (b)between females at different phases of the menstrual cycle. The outcome measures included the number of jumps in the square-hop test and ankle and knee proprioception, which were assessed by an electric-driven movable frame rotated at 0.4 deg/s and isokinetic muscle strength measured by a computerized dynamometer (Biodex). For the square-hop test (p = .006), ankle dorsiflexion/plantar flexion (p < .05), knee flexion/extension (p < .05), the relative peak torque of the isokinetic muscle strength at the 60° and 180° knee flexion/extension (p < .001), and the 30° and 120° ankle plantar flexion/dorsiflexion (p < .05) between females and males showed significant differences. For the females at different phases of the menstrual cycle, significant differences were found on ankle dorsiflexion (p = .003), plantar flexion (p = .023), knee extension (p = .029), the square-hop test (p = .036), and relative peak torque of isokinetic muscle strength at 180° knee flexion (p = .029). This study demonstrated that there are sex differences in lower limb proprioception and mechanical function. Females at ovulatory and luteal phases have better lower limb proprioception than at the follicular phase.

Coupled CAD-CFD automated optimization for leading and trailing edge of an axial impulse turbine blade

A bidirectional impulse turbine with fixed guide vanes is used in an oscillating water column to extract wave energy. The turbine suffers from low aerodynamic efficiency, and it is required to improve performance. In the present study, coupled CAD-CFD automated optimization of the blade leading and trailing edge ratio was performed to maximize the efficiency. The design points were generated using a central composite design sampling technique and response surface optimization method estimated the optimum design. The optimization pipeline was automated using the Ansys Design Exploration module. Ansys Turbo Grid was used for generating structured hexahedral elements in the computational domain, and the problem was solved in Ansys CFX® v16.2. The results showed that the modified leading and trailing edge enhanced the performance compared to the reference blade by minimizing the pressure drop. The optimized design improved the relative peak efficiency and torque by 3.4% and 2% respectively. Additionally, a detailed flow analysis has been reported in this paper.

Muscle Strength Cutoff Points for Functional Independence and Wheelchair Ability in Men With Spinal Cord Injury

ObjectiveDetermine trunk and shoulder muscle strength cutoff points for functional independence and wheelchair skills, and verify the predictive capacity of relative and absolute peak torque in men with spinal cord injury (SCI). DesignCross-sectional study. SettingRehabilitation hospital setting. ParticipantsMen (N=54) with SCI were recruited and stratified into high and low paraplegia groups. InterventionsAll participants performed maximum strength tests for shoulder abduction or adduction (isokinetic) and trunk flexion or extension (isometric) to determine relative and absolute peak torque cutoff points for the Spinal Cord Independence Measure version III (SCIM-III) and Adapted Manual Wheelchair Circuit (AMWC). Main outcome measuresThe primary outcome measures were SCIM-III, AMWC-Brazil test, and strength variables (peak torques). Demographic characteristics obtained from participants’ electronic medical records were the secondary outcomes used as predictor variables of functional independence. ResultsThe best predictive model for SCIM-III (R=0.78, P≤.05) used the sum of trunk flexion and extension relative peak torque values to determine the cutoff points (1.42 N·m/kg for a score of 70). Relative shoulder abduction peak torque was used in the predictive models for AMWC outcomes: performance score (R=0.77, P≤.05, cutoff points of 0.97 N·m/kg for 300.0m) and 3-minute overground wheeling (R=0.72, P≤.05, cutoff points of 0.96 N·m/kg for 18.5s). ConclusionsRelative peak torque showed better predictive capacity compared to absolute peak torque. Cutoff points were established for relative muscle strength and could help health professionals set appropriate goals for individuals with SCI to achieve high functional independence and wheelchair ability.

Diagnostic value of the hamstring to quadriceps ratio in monitoring of the effectiveness of supervised 6-month physiotherapy in males after Anterior Cruciate Ligament Reconstruction (ACLR)

The aim of the study was to assess the usefulness of isometric torque (IT) and peak torque (PT) of the hamstring to quadriceps muscles ratio (H/Q ratio) in monitoring the effectiveness of physiotherapy (PH) in males after ACLR. The H/Q ratio is a diagnostic tool for monitoring of the effectiveness of the 6- month PH after ACLR. Twenty males 6 months after ACLR (ACLR group) and 20 male controls underwent IT and PT (60°/s and 180°/s) bilateral measurements of H and Q muscles. The IT and PT were normalized to body mass, and expressed as relative IT (RIT) and relative PT (RPT). The RIT and RPT H/Q ratios, and Limb Symmetry Index (LSI) were calculated. In the ACLR group, the RIT for the H and Q, the RIT for the H/Q ratio and most of the RPT, as well as the H/Q ratio, ROM and LSI values of the operated knee, were not significantly different (NSD) than those of the non-operated side (NOS) or the control group. The between-group comparison of the H/Q ratio for RIT and RPT weren't NSD. The isokinetic test at 180 °/s showed lower RPT, H/Q ratio and LSI values for the Q muscle than those of the NOS (p = 0.042, p = 0.001). The H/Q ratio, in combination with the RIT, RPT and LSI, is a useful diagnostic tool for monitoring the effectiveness of 6-month PH after ACLR. Restoring the correct H/Q ratio can reduce the risk factor for ACL graft rupture.

Body fat, but not muscle quality, is related to perceived fatigue in young-adult active and inactive women

The purpose of this study was to investigate the association of perceived fatigue with body composition and muscle quality (strength, thickness and specific torque) in young adult women. Fifty-one healthy women (31.98 ± 6.88 years) were assessed regarding perceived fatigue, body composition, knee extensors muscle strength, muscle thickness, and muscle quality. The short version of International Physical Activity Questionnaire was applied to classify subjects as active or inactive. To examine the relationship between perceived fatigue and dependent variables, the Pearson’s correlation was performed. Perceived fatigue was significantly correlated (p < 0.05) with body weight (r = 0.469), body mass index (r = 0.369), fat mass (r = 0.469), percent body fat (r = 0.396), and relative peak torque (r = -0.378). Additionally, inactive women had significantly greater (p < 0.05) body weight, body mass index, fat mass, percent body fat, and perceived fatigue than active women. Perceived fatigue is related to body weight and fat mass, but not to muscle strength or muscle quality. Moreover, physically active women showed lower perceived fatigue, body weight, and body fat compared to physically inactive women. These results suggest that body fat may play a role in perceived fatigue and physical activity could attenuate such symptom.

Obesity, but not metabolic control, is associated with muscle strength and endurance in diabetic older adults

The objective of this study is to investigate the association between muscle function, body composition, and metabolic control in adults with type 2 diabetes mellitus (DM2). Forty-eight individuals with DM2 were divided into four groups according to the severity of obesity (body mass index [BMI]: lean [LN, n = 10], overweight [OW, n = 16], obese class I [OBI, n = 15], and obese class II [OBII, n = 7]). Absolute peak torque (TQ), relative peak torque (TQ/body weight [BW]), total work (TW), and fatigue index (FI) were assessed by means of an isokinetic dynamometer during concentric knee extensor contraction. Spearman's correlation coefficients were used to estimate the association between measurements. Although OBII had higher insulin levels than both LN and OW groups, no significant differences were found between groups for TQ, TQ/BW, TW, and FI, as well as between metabolic variables and muscle measurements. There was a positive correlation between BMI and TQ (rs = .45) and resistance tests, between BMI and TQ (rs = .43), and TW (rs = .37). Metabolic variables do not correlate with muscle strength and endurance in DM2. However, severity of obesity measured by the BMI is positively associated with muscle force-generating capacity and endurance.

Maximal oxygen uptake and concentric isokinetic muscle strength in pubertal football trained and untrained boys of the same biological age

The purpose of the present study was to examine the effects of long term (prolonged) football training on maximal oxygen uptake (VO2) and isokinetic muscle strength in young football players and untrained boys of the same biological age. Twenty football competitive boys (mean age 14 ± 0 yrs; height 165.5 ± 8.5 cm; weight 59.9 ± 9.5 kg; years of training 7 ± 3) and eighteen untrained school boys (mean age 14 ± 0; height 168.22 ± 10.46 cm; weight 59.3 ± 9.9 kg) of the same biological age volunteered to participate in the study. Sexual maturation classified according to Tanner’s stage 3. The football players participated both in their school’s physical education program and in their football team training program while the untrained group participated only in their school’s physical education program (2–3 times per week for 40 min). All subjects were tested for maximal oxygen uptake (VO2) and respiratory exchange ratio (RER) on the treadmill using an open circuit spirometry. The isokinetic peak torque values of quadriceps (Q) and hamstrings (H) as well as the H : Q strength ratios were recorded. Hcon : Qcon was calculated as the ratio of the peak concentric torque of H to the peak concentric torque of the Q. Results showed that the trained group had significantly lower heart rate in rest (p < 0.001), higher RER (p < 0.001), maximal blood lactate (BLmax) (p < 0.001) and higher VO2 max in both relative and absolute values (p < 0.001) compared to the untrained group. At angular velocities of 60 ° s−1 and 180 ° s−1 the relative peak torque of Q and H were significantly higher (Q = p < 0.01; H = p < 0.01). However, the absolute values of Q and H as well as the H : Q ratios at all angular velocities did not differ significantly between the two groups. The results suggest that systematic football training (intensity and duration) has a positive effect in metabolic capacity, cardiorespiratory system and neuromuscular function.

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).

Comparison in Peak Torque Rotations Between Dominant and Non-Dominant Arms in Powerlifters

The shoulder joint is naturally instable because of anatomic structure, and depends of passive and active elements, ligaments and muscle, respectively, for proper stability. The bench press, upper body exercise, is one of three exercises of Powerlifting (PL), based on maximum strength. The strength balance between dominant (D) and non-dominant (ND) upper limbs is fundamental to develop a good lift and joint safety. Therefore, not only major muscles are important as pectoral major, but also stability muscles as rotator cuff for shoulder external rotation. PURPOSE: To compare, in recreational powerlifters, relative peak torque between dominant and non-dominant arms, in external and internal rotation at 60°/s and 180°/s concentric action velocity for external (ER) and internal rotation (IR) in shoulder joint. METHODS: Participants, nine powerlifters (height: 1.73±0.06cm; weight: 84.1±13.0kg; bench press 1 repetition maximum: 116.4±19.1kg; PL minimal experience: 2 years). The muscle group strength for ER and IR were assessed bilateral by Biodex System 4Pro isokinetic dynamometer. The participants were in a seated position, 45° shoulder abduction, 60°/s and 180°/s concentric mode was adopted for lever velocity for ER and IR in shoulder joint. Dominant and non-dominant sides peak torque normalized to body weight (PT/BW; Nm.kg-1) were compared with paired student’s t-test. RESULTS: Significant difference (p=0.02) was found at the PT/BW for the ER movements between the dominant (47.8±5.8 Nm.kg-1) and non-dominant (44.3±6.1Nm.kg-1) sides at the velocity of 60°/s, but there was no significant difference between sides in IR (p=0.15; D=71.7±16.3Nm.kg-1, ND=66.1±12Nm.kg-1); and at 180°/s for ER (p=0.24; D=48±5.3 Nm.kg-1, ND=45.7.1±8.6 Nm.kg-1) and IR (p=0.24; D=68.7±15.5Nm.kg-1, ND=64.6±8.6 Nm.kg-1). CONCLUSION: For recreational powerlifters, there is only difference between dominant and non-dominant arms in ER movement at 60°/s, which suggests a necessity of unilateral exercises for a better balance between sides. Supported by CNPq scholarship.

Photobiomodulation therapy is beneficial in reducing muscle fatigue in Brazilian jiu-jitsu athletes and physically active men

Photobiomodulation therapy (PBMT) applied prior to exercise may provide ergogenic effects by delaying the onset of fatigue. The Brazilian jiu-jitsu (BJJ) is a domain combat sport in which elbow flexors’ isometric contraction is commonly performed. This study was aimed at investigating the effects of PBMT on torque parameters in groups of BJJ athletes (n = 10) and physically active men (n = 10). The strength testing protocol was composed of elbow flexors’ maximal isometric voluntary contractions at 90°; treatment application (placebo or PBMT); fatigue protocol; and one elbow flexors’ maximal isometric voluntary contraction. Magnitude-based inference analyses were used to examine practical significance. BJJ athletes presented higher relative isometric peak torque values pre (ES = 0.92) and post (ES = 1.32) fatigue protocol than those observed in physically active men. Beneficial results were shown in the time to exhaustion (difference: 5.5 s, likely beneficial) and impulse during fatigue test (difference 271.1 N m s, possibly beneficial) for physically active men and in the impulse for BJJ athletes (difference 179.0 N m s, possibly beneficial) in favor of PBMT compared to placebo. The PBMT was efficient in delaying the onset of fatigue regardless of the individuals’ training level and could be suggested as an ergogenic factor to improve muscle performance.

Results and analyses of preoperative isokinetic and balance tests in patients with chronic lateral ankle instability who underwent surgical treatments

Category: Sports Introduction/Purpose: To (1) describe muscle strength and postural stability in patients with chronic lateral ankle instability, and (2) analyze the correlation between weakness of muscle strength and deficits of postural stability Methods: Results of preoperative isokinetic and balance tests in 203 patients whose contralateral ankle was normal were retrospectively reviewed. Isokinetic peak torque values of eversion and inversion at 2 angular velocities (30°/s, 120°/s) were measured in injured and normal ankles. In balance test, the percent differences of 3 actual scores (Overall, Anterior-Posterior, and Medial-Lateral) between injured and normal ankles were calculated. Additional statistical analyses were performed to describe weakness of muscle strength, deficits of postural stability, and their correlation. Results: There were significant differences in 4 peak torque values and 4 relative peak torque values (peak torque/body weight) between injured and normal ankles. Eight values were significantly lower in injured ankles. Weakness was severe during inversion and at 30°/s. In balance test, 49 subjects (24.1%) had significant deficits in postural stability; the results in 109 subjects (53.7%) were favorable. There was no strong association between weakness of muscle strength and deficits of postural stability. Conclusion: Considering correlation between weakness of muscle strength and deficits of postural stability, strength measurement alone is insufficient in evaluating preoperative functional ability, and other functional test such as postural stability test is required. In addition, the results of this study may provide further evidence for rehabilitation program consisting of proprioceptive training as well as muscle strengthening.

The relation between force production at different hip angles and functional capacity in older women

Although hip muscles are related to activities of daily living (ADLs) in older adults, there is a lack of evidence concerning the extensor–flexor hip torque–angle. A shift of the torque–angle relationship is caused by the aging process (increasing or reducing the range of motion) affecting the force production in a given muscular length during ADLs. Thus, the relationship between hip extensor–flexor muscles' force production and their association with functional capacity tests in elderly women were evaluated. Seventeen elderly women performed timed up and go, timed up and down stairs, and 30-s chair stand tests. Hip extensor–flexor isometric peak torques at 15°, 60°, 90°, and 100° (0° = full extension) were also assessed. Hip flexors produced the highest absolute and relative peak torque at a 15° angle and hip extensor muscles at 100°. A large and significant correlation (r = 0.62, p = 0.008) was observed only between absolute hip extensor peak torque at 90° and the 30-s chair stand test. When peak torque was normalized by body mass, the hip extensor–flexor muscles' peak torque obtained at all measured angles presented significant correlation with the 30-s chair stand test. The results indicate that for older women there is an optimum torque–angle for the hip flexor and extensor muscles. Furthermore, although the hip torque–angle relationship was measured under isometric contractions, there was a correlation with the 30-s chair stand test, which could indicate the presence of the isometric component during this movement.