Knee Extensor Peak Torque Research Articles

E-34 Free Communication/Poster - Dance

Sleep patterns and their disorders in patients with osteoarthritis (OA) have been studied because they can modify the physical and functional aspects of the disease. PURPOSE: The present study aimed to verify the influence of obstructive sleep apnea (OSA) on knee extensor torque, pain, stiffness and physical function in men with low-grade knee OA. METHODS: The study included 60 male volunteers between 40 and 70 years of age divided into 4 groups: G1 (n=15): without OA or OSA; G2 (n=15): without OA and with OSA; G3 (n=15): with OA and without OSA; and G4 (n=15): with OA and OSA. All volunteers were examined using knee x-rays and polysomnography, responded to the WOMAC questionnaire and completed a test on an isokinetic dynamometer to evaluate peak isometric knee extensor torque, both concentric and eccentric (90°/s and 180°/s). Comparisons of the means were performed using a General Linear Model. RESULTS: The results on the sleep pattern of the volunteers showed between-group differences for stage 1, with G2 and G4 showing a higher percentage of stage 1 compared to G1 (p<0.05). The number of arousals was higher in G4, which significantly differed from G1 (p<0.05), and an identical result was observed for G2 which, differed from that for G1 (p<0.05). Regarding the data from the WOMAC questionnaire (pain, stiffness and physical function), it was observed that for all domains, G4 showed higher values compared to G1 or G2 (p<0.05). For the concentric isometric and isokinetic peak knee extensor torque (90°/s and 180°/s), lower values were observed in G4 compared to G1 or G2 (p<0.05). CONCLUSION: It can be concluded that OSA negatively affects sleep, peak extensor torque, pain, stiffness and physical function in patients with low-grade OA. Supported by FAPESP Grant (#11/06619-7 and #10/19437-1)

Relationship between knee extensor torque and physical function in men with early knee osteoarthritis

Relationship between knee extensor torque and physical function in men with early knee osteoarthritis

Effect of Whole-Body Vibration on Muscle Strength and Balance in Diplegic Cerebral Palsy

The purpose of this study was to investigate the effects of whole-body vibration training on muscle strength and balance in children with diplegic cerebral palsy. Fifteen children were assigned to the experimental group, which received whole-body vibration training (9 mins per day, 5 days per week). Another 15 were assigned to the control group, which participated in a traditional physical therapy exercise program for 3 successive months. Baseline and posttreatment assessments were performed using the Biodex isokinetic dynamometer to evaluate the knee extensors peak torque at 60 degrees per second and 90 degrees per second and using the Biodex balance system to evaluate stability index. The children in the experimental group showed a significant improvement when compared with those in the control group (P < 0.001). The peak torque at 60 degrees per second and 90 degrees per second after treatment was 28.8 ± 0.45 and 47.5 ± 0.7 N · m and 30.9 ± 0.68 and 54.2 ± 1.7 N · m for the control and the experimental group, respectively. The overall stability index after treatment was 2.75 and 2.2 for the control group and the experimental group, respectively. Whole-body vibration training may be a useful tool for improving muscle strength and balance in children with diplegic cerebral palsy.

The comparison of muscle strength and short-term endurance in the different periods of type 2 diabetes

BackgroundPatients with type 2 diabetes (T2DM) are subjected to reduction in the quality and oxidative capacity of muscles. The effect of duration of diabetes on the muscle endurance response is not clear and strength as well.ObjectiveThe aim of this study was the assessment of strength and endurance of knee extensor and flexor in the patients with T2DM < 10 and T2DM > 10 years in comparison with age, sex, BMI, ABI and PAI-matched health control subjects.MethodsIsometric maximal peak torque (MPT) of knee extensor and flexor before and after 40 isokinetic repetitions with velocity of 150 degree/s were recorded in 18 patients with T2DM < 10 Y , 12 patients with T2DM > 10 Y and 20 matched health control (HC) groups.ResultsBoth diabetic patient groups had significant lower isometric and isotonic knee extensor and flexor strength than HC. The endurance indices indicated that whereas the isometric MPT of flexor movement was reduced after isokinetic protocol in the both patient groups in comparison with HC, the less decline was seen in the isotonic torque and work during isokinetic protocol in the T2DM > 10 Y group in comparison with two other groups. The HbA1c and FPG were significantly correlated with strength not with endurance indices.ConclusionsIt seems the progression of diabetes accompanied with vascular, neural and muscular deficits activate, some adaptive and compensatory processes which can maintain muscle performance.

Evidence for reduced neuromuscular function in men with a history of androgen deprivation therapy for prostate cancer

Indices of body composition and muscular strength were compared between men with prostate cancer (PCa) treated with androgen deprivation therapy (ADT) and asymptomatic matched men. Nine subjects aged 63-83years with PCa who received ADT (PCa+ADT; duration 6-180months) and 11 asymptomatic aged-matched eugonadal men (HM) aged 59-80years were assessed for prostate-specific antigen (PSA) and total testosterone (TT). Total body non-osseous lean mass (TBLM) and right thigh non-osseous fat-free mass (RTLM) were assessed using dual-energy X-ray absorptiometry. Peak torque of the right knee extensors at 0°s(-1) (ISO) and 60°s(-1) (CON), maximal handgrip strength of the dominant hand (MHS) and whole-body strength (WBS) were assessed. ISO and CON per unit mass of RTLM and MHS and WBS per unit mass of TBLM were calculated. Age, height, mass, body mass index and prostate-specific antigen were comparable between groups (P>0·05), while TT was lower in PCa+ADT (P<0·01). RTLM was similar between groups (P≥0·075). Absolute ISO and CON were lower for PCa+ADT (P<0·01) as were CON per unit of RTLM and ISO per unit of RTLM (P<0·05). Absolute MHS, WBS and MHS per unit of TBLM and WBS per unit of TBLM were lower for PCa+ADT (P<0·01; P<0·05). Men with PCa who receive ADT experience significant losses in whole-body muscular strength compared with asymptomatic age-matched men, which may impair functional capacity. These losses in muscular strength appear to involve neuromuscular mechanisms that are yet to be identified.

Effect of cryotherapy on muscle recovery and inflammation following a bout of damaging exercise

The purpose of this study was to determine the effect of cryotherapy on the inflammatory response to muscle-damaging exercise using a randomized trial. Twenty recreationally active males completed a 40-min run at a -10% grade to induce muscle damage. Ten of the subjects were immersed in a 5°C ice bath for 20min and the other ten served as controls. Knee extensor peak torque, soreness rating, and thigh circumference were obtained pre- and post-run, and 1, 6, 24, 48, and 72h post-run. Blood samples were obtained pre- and post-run, and 1, 6 and 24h post-run for assay of plasma chemokine ligand 2 (CCL2). Peak torque decreased from 270±57 Nm at baseline to 253±65 Nm post-run and increased to 295±68Nm by 72h post-run with no differences between groups (p=0.491). Soreness rating increased from 3.6±6.0mm out of 100mm at baseline to 47.4±28.2mm post-run and remained elevated at all time points with no differences between groups (p=0.696). CCL2 concentrations increased from 116±31pgmL(-1) at baseline to 293±109pgmL(-1) at 6h post-run (control) and from 100±27pgmL(-1) at baseline to 208±71pgmL(-1) at 6h post-run (cryotherapy). The difference between groups was not significant (p=0.116), but there was a trend for lower CCL2 in the cryotherapy group at 6h (p=0.102), though this measure was highly variable. In conclusion, 20min of cryotherapy was ineffective in attenuating the strength decrement and soreness seen after muscle-damaging exercise, but may have mitigated the rise in plasma CCL2 concentration. These results do not support the use of cryotherapy during recovery.

An Isokinetic Training Program for Reducing Falls in a Community-Dwelling Older Adult

With the population older than 65 years, projected to double by the year 2030, falls in older adults are a substantial health concern. Muscle strength deficits are one of the multifactorial components linked to increased fall risk, and decreasing these deficits has been one of the goals of interventions designed to decrease fall risk. These interventions have traditionally focused on improving peak torque; however, recent research suggests that exercise protocols that focus on the rate of torque development (RTD) may be more effective in decreasing fall risk. This case report examines clinical outcomes following implementation of an isokinetic strengthening protocol coupled with a balance program designed to reduce fall risk in a community-dwelling older adult. The individual was a 70-year-old woman with a history of 3 falls over the past 8 months and no related medical etiology who had self-limited her activities because of fear of another fall. She was classified as having substantial risk for future falls because of fall history, increased fear of falling, and below age norms on the Berg Balance Scale (BBS), and the Timed Up and Go (TUG). The treatment program consisted of 12 weeks of high-intensity isokinetic knee extensor training, high challenge dynamic gait and balance activities, and core strengthening. The isokinetic protocol consisted of 4 sets of 10 concentric-only repetitions at speeds of 240°/sec and 300°/sec for a total of 8 work sets. Dynamic gait activities incorporating directional and obstacle drills, and rocker and balance boards were used for balance training activities. Progressive theraband exercises were used for core strengthening. As her home program, the participant was encouraged to return to line dancing twice per week. During the 12-week protocol, the participant completed two 90-minute therapy sessions and two 90-minute dance classes per week. After the 12 weeks of treatment, knee extensor peak torque at 150 ms improved on the right from 67.8 N to 107.1 N (57.9% increase), and on the left from 65.1 N to 97.6 N (49.9% increase). The BBS score improved from 45 to 52; and the TUG improved from 14.0 to 8.6 seconds. Both final scores exceeded fall risk cutoffs (BBS = 48; TUG = 13.5 seconds) and the change score exceeded minimal detectable change (BBS = 7; TUG 5.4 seconds). The treatment program produced improvements in knee extensor peak torque and RTD, but more importantly, the final scores on the clinical outcome measures placed the participant above established fall-risk cutoff scores. Although future research with increased numbers of participants and a control group should be conducted to confirm this study's results, these findings support the use of isokinetic training to reduce fall risk in older adults.

다양한 지지면에서의 스쿼트 운동이 무릎관절 근력 및 위치감각 향상에 미치는 영향

Purpose : The purpose of this study was to compare the Effects of Knee Extensor, Flexor Muscle Strength and Joint Position Sense in Squat Exercise on Variety Surface. Method : Subjuects were consisit of 30 male and female who had non disorder knee joint. we had devided 3 group(control group, balance pad group, and togu group) and we measured that knee joint 15°/45°proprioception(position sense) and Peak Torque of knee extensor, flexor muslce at 60°/sec, 180°/sec angular velocity. Result : First, knee joint 15°proprioception(position sense) of balance pad and togu group was significantly different after exercise(p<.05), but only balance pad group was significantly different at knee joint 45°. Second, knee extensor Peak Torque of balance pad and togu group was significantly different at 60°/sec, 180°/sec angular velocity(p<.05). Third, knee flexor Peak Torque of balance pad and togu group was significantly different at 60°/sec, 180°/sec angular velocity(p<.05). Conclusion : Squat exercises on the balance pad and togu were affects knee joint proprioception and muscle strength improvement. These results suggest that squat exercise on the unstable surface is effective for prevention of knee joint injury and functional activity.

Comparison of hamstring/quadriceps ratio between isoinertial and isokinetic measurements

OBJECTIVE: To determine the applicability and predictive accuracy of an isoinertial resistance machine for the assessment of hamstring/quadriceps conventional (concentric) ratio (CR). METHOD: Thirty-two resistance trained young men (23.53 ± 3.2 yrs) were tested using dedicated instruments to obtain the peak torque (PT) of the right knee extensors and flexors as well as the corresponding one repetition maximum (1RM) values. All measurements were conducted in the concentric mode. RESULTS:Significant ( p< 0.05) correlations were indicated between knee extensor and flexor PT and 1RM values (r = 0.73 to 0.75), as well as between PT and 1RM CR values (r = 0.65). However the isoinertial CR values (0.42 ± 0.05) were significantly ( p< 0.05) greater than their isokinetic counterparts (0.36 ± 0.04). CONCLUSION: Caution should be used when comparing isoinertial CR with population-specific isokinetic normative scores.

An Increase in School-Based Physical Education Increases Muscle Strength in Children

Children and adolescents are encouraged to maintain a habitually active lifestyle because of the known health benefits associated with regular physical activity, but there are some reports that a high level of activity may be associated with increased fracture risk. This prospective controlled exercise intervention study in prepubertal children evaluated if a school-based exercise intervention could enhance growth-related gains in muscle strength and muscular function without affecting fracture risk. Fractures were registered in 417 girls and 500 boys age 7-9 yr in the intervention and in 836 age-matched girls and 872 boys. The intervention included 40 min·d of school physical education for 2 yr, whereas the controls achieved 60 min·wk. In a subsample consisting of 49 girls and 80 boys in the intervention and 50 girls and 53 boys in the control group, body composition was measured by dual-energy x-ray absorptiometry, muscle strength by isokinetic peak torque (PT) of the knee extensors, and flexors at 60 and 180°·s by a computerized dynamometer and neuromuscular performance by vertical jump height. The rate ratio (95% confidence interval) for children in the intervention group to sustain a fracture was 1.07 (0.66-1.68). The annual gain in knee extensor PT at 180°·s was significantly higher for both girls (P < 0.001) and boys (P < 0.01) in the intervention compared with the control group. Boys in the intervention group also had a greater annual gain in knee flexion PT at 180°·s (P < 0.001), and girls had a greater gain in vertical jump height (P < 0.05). An increase in school-based physical education from 60 to 200 min·wk enhanced muscle strength in prepubertal children without affecting fracture risk.

Poor correlation between handgrip strength and isokinetic performance of knee flexor and extensor muscles in community‐dwelling elderly women

To investigate the correlation between handgrip strength and performance of knee flexor and extensor muscles determined using an isokinetic dynamometer in community-dwelling elderly women. This was a cross-sectional study. Sample selection for the study was made by convenience, and 221 (71.07 ± 4.93 years) community-dwelling elderly women were included. Knee flexor and extensor muscle performance was measured using an isokinetic dynamometer Biodex System 3 Pro. The isokinetic variables chosen for analysis were peak torque, peak torque/bodyweight, total work/bodyweight, total work, average power, and agonist/antagonist ratio at the angular velocities of 60°/s and 180°/s. Assessment of handgrip strength was carried out using the Jamar dynamometer. Spearman's correlation coefficient was calculated to identify intervariable correlations. Only knee flexor peak torque (60°/s) and average power (60°/s), and knee extensor peak torque (180°/s) and total work (180°/s) were significantly (P < 0.05), yet poorly, correlated with handgrip strength (r < 0.30). The majority of analyses did not show any correlation between variables assessed by isokinetic dynamometer and handgrip dynamometer. Caution is required when generalizing handgrip strength as a predictor of global muscle strength in community-dwelling elderly women.

Effects of exercise-induced muscle damage on resting metabolic rate, sub-maximal running and post-exercise oxygen consumption

Exercise-induced muscle damage (EIMD), described as the acute weakness of the musculature after unaccustomed eccentric exercise, increases oxidative metabolism at rest and during endurance exercise. However, it is not known whether oxygen uptake during recovery from endurance exercise is increased when experiencing symptoms of EIMD. Therefore, the purpose of this study was to investigate the effects of EIMD on physiological and metabolic responses before, during and after sub-maximal running. After a 12 h fast, eight healthy male participants completed baseline measurements comprising resting metabolic rate (RMR), indirect markers of EIMD, 10 min of sub-maximal running and 30 min of recovery to ascertain excess post-exercise oxygen consumption (EPOC). Measurements were then repeated at 24 and 48 h after 100 Smith-machine squats. Data analysis revealed significant (P<0.05) increases in muscle soreness and creatine kinase (CK) and decreases in peak knee extensor torque at 24 and 48 h after squatting exercise. Moreover, RMR, physiological, metabolic and perceptual responses during sub-maximal running and EPOC were increased in the two days after squatting exercise (P<0.05). It is suggested that the elevated RMR was a consequence of a raised energy requirement for the degradation and resynthesis of damaged muscle fibres. The increased oxygen demand during sub-maximal running after muscle damage was responsible for the increase in EPOC. Individuals engaging in unaccustomed resistance exercise that results in muscle damage should be mindful of the increases in resting energy expenditure and increased metabolic demand to exercise in the days that follow.

Reliability of isokinetic evaluation in passive mode for knee flexors and extensors in healthy children

The isokinetic dynamometer has been considered the gold-standard measurement of muscle performance. However, the reliability for the passive mode in children has not been reported to date. The purpose was to evaluate the reliability of the isokinetic dynamometer in passive mode in children. Twenty-one healthy children (ten girls, eleven boys), aged 5 to 12 years (age: 8.5±2.2 years), were evaluated using an isokinetic dynamometer. Each participant was tested twice with a one-week interval and performed five consecutive cycles of knee extension and flexion. The test was performed at 60º/s in the concentric passive mode and the children performed maximal contractions. The measured variables were peak torque, average peak torque, total work, and average power, time to peak torque and angle of peak torque for dominant and non-dominant lower limbs. Reliabilities were determined using intraclass correlation coefficient (ICC3,1), standard error of measurement (SEM and SEM%), and coefficient of variation (CV). We found good reliability in both lower limbs for peak torque, average peak torque, total work and average power of knee flexors and extensors, with ICC3,1 values greater than 0.80; SEM ranging from 6.7 to 79.2; SEM% ranging from 10.4% to 16.8%; CV lower than 15%. Bland-Altman analysis showed that the bias was low than 10% and limits of agreement (LOAs) ranging from 33.9% to 59.2%, and -28.8% and -52.8%, showing that measures tended to disagree. However, time to peak torque (ICC3,1<0.68; SEM > 0.34; SEM%>37.4%; CV>41.7%; bias >24.0%; LOA>101.0%) and angle of peak torque (ICC3,1<0.76; SEM>9.3; SEM%>27.6%; CV>15.3%; bias>11.0%; LOA>61.0%) were not reliable. The findings indicate that isokinetic evaluation in passive mode for knee extensors and flexors of dominant and non-dominant lower limbs of children without disabilities was reliable for peak torque, average peak torque, work, and power. However, average time to peak torque and angle of peak torque were not reliable.

A Feasibility Study of the Effect of Intra-Articular Corticosteroid Injection on Isokinetic Muscle Strength in Children With Juvenile Idiopathic Arthritis

This study assessed the magnitude of changes in isokinetic muscle strength in children with juvenile idiopathic arthritis (JIA) before and after treatment with intra-articular corticosteroid injection and assessed the feasibility of a larger study of the same effect. Isokinetic dynamometry was used to measure peak knee extension and flexion torque in 12 children before and after treatment for unilateral knee arthritis. Extensor and flexor strength was reduced on the affected side before treatment (-0.56 Nm/kg, p = .004 and -0.24 Nm/kg, p = .02 respectively). Increases in extensor strength were observed at two weeks (p = .01) and twelve weeks postinjection (p = .03). Improvements at 6 weeks approached but did not reach statistical significance (p = .17). Improvements in flexor strength were not observed until 12 weeks postinjection (p = .03). Despite significant improvements in extensor strength, low peak knee extensor torque continued to be observed at 12 weeks (p = .01). Knee extensor and flexor strength is reduced in children with JIA with active arthritis and improves following intra-articular corticosteroid injection. Significant improvements in knee extensor and flexor strength were seen postinjection; however deficits in extensor strength were still evident at three months. Isokinetic dynamometry was safe and well tolerated in our sample of children with JIA with active arthritis.

Effects of Training Attendance on Muscle Strength of Young Men after 11 Weeks of Resistance Training

Training attendance is an important variable for attaining optimal results after a resistance training (RT) program, however, the association of attendance with the gains of muscle strength is not well defined. Therefore, the purpose of the present study is to verify if attendance would affect muscle strength gains in healthy young males. Ninety two young males with no previous RT experience volunteered to participate in the study. RT was performed 2 days a week for 11 weeks. One repetition maximum (1RM) in the bench press and knee extensors peak torque (PT) were measured before and after the training period. After the training period, a two step cluster analysis was used to classify the participants in accordance to training attendance, resulting in three groups, defined as high (92 to 100%), intermediate (80 to 91%) and low (60 to 79%) training attendance. According to the results, there were no significant correlations between strength gains and training attendance, however, when attendance groups were compared, the low training attendance group showed lower increases in 1RM bench press (8.8%) than the other two groups (17.6% and 18.0% for high and intermediate attendance, respectively). Although there is not a direct correlation between training attendance and muscle strength gains, it is suggested that a minimum attendance of 80% is necessary to ensure optimal gains in upper body strength.

Association between IGF-2 gene and fat-free mass in response to resistance training

BACKGROUND: It is well established that the human aging process is associated with a significant decline in neuromuscular function and performance. Twin studies demonstrate that genetic factors partially explain the inter-individual variation of fat-free mass (FFM) and muscle strength. PURPOSE: To examine the association between the polymorphism of the gene IGF-2 with phenotypes strength and muscle mass of elderly women pre and post resistance training. METHODS: 76 elderly women participated in this analysis. These volunteers, who should be sedentary for at least 6 months before the study, were assigned four groups in relation to allele GAGG, AA, GAAA and GG. The first analysis compared 60 elderly women with GG and GA allele (GAGG) versus 16 elderly women with AA allele. The second analysis compared 54 elderly women with GA and AA (GAAA) versus 22 elderly women GG allele. The Body mass index, fat free mass, fat mass and Isokinetic Muscle Peak Torque were measured. All volunteers were participating in the Resistance Training program. The DNA was extracted from peripheral venous blood leukocytes using a salting out protocol. The primer for IGF-II gene exon 9 was 5’-GTCCCTGAACCAGCAAAGAG-3’ 0.5 μM (0.625 μl) Primer R-5’-TGATGGAAAAGGGAGTGAGG-3’ 0.5 μM (0.625 μl), Taq DNA Polimerase enzime 0.5 U (0.1 μl), água milli-Q (3.8 μl) 5 hg de DNA (3 μl). PCR amplification was performed in a programmable thermal cycler GeneAmp? PCR System 9700. RESULTS: The results of the first analysis GAGG × AA versus the group AA showed the relative increase in knee extensor peak torque relative and also in the fat-free mass and showed a decrease in the fat mass percentage in the GAGG group. The second analysis considered the group GAAA versus group GG showed decreases in the fat-free mass percentage in the GAAA group, also showed the relative increase in the fat-free mass in the GG group and decrease in the fat mass percentage in the GG group. CONCLUSIONS: The results of this study show that 24 weeks of the resistance training improved strength and muscle mass and decreased the fat mass. The results confirm this assertion and suggest the G allele presents more influence over the A allele, in relation to phenotypes strength and muscle mass in elderly women after resistance training.

Relationship between muscle mass and physical performance: is it the same in older adults with weak muscle strength?

the relationship between muscle mass and physical performance has not been consistent among studies. to clarify the relationship between muscle mass and physical performance in older adults with weak muscle strength. cross-sectional analysis using the baseline data of 542 older men and women from the Korean Longitudinal Study on Health and Aging. dual X-ray absorptiometry, isokinetic dynamometer and the Short Physical Performance Battery (SPPB) were performed. Two muscle mass parameters, appendicular skeletal mass divided by weight (ASM/Wt) and by height squared (ASM/Ht(2)), were measured. We divided the participants into a lower-quartile (L25) group and an upper-three-quartiles (H75) group based on the knee-extensor peak torque. Correlation analysis and logistic regression models were used to assess the association between muscle mass and low physical performance, defined as SPPB scores <9, after controlling for confounders. in the L25 group, no correlation between mass and SPPB was detected, whereas the correlation between peak torque and SPPB was significant and higher than that in the H75 group. Results from the logistic models also showed no association between muscle mass and SPPB in the L25 group, whereas muscle mass was associated with SPPB in the H75 group. muscle mass was not associated with physical performance in weak older adults. Measures of muscle strength may be of greater clinical importance in weak older adults than is muscle mass per se.

Knee extensor torque of men with early degrees of osteoarthritis is associated with pain, stiffness and function

Osteoarthritis (OA) is a chronic-degenerative disease. The knee is the most commonly affected joint and the symptoms are generally attributed to quadriceps muscle weakness. However, few studies have evaluated this relationship in a population with early stages of knee OA. To investigate whether a correlation among the knee extensor torque and the three subscales of the WOMAC questionnaire in men with early stages of knee OA exists. Twenty-one men with knee OA grades I or II (according to Kellgren and Lawrence criteria) participated in this study. The concentric and eccentric knee extensor torque were assessed using a Biodex System 3 Pro® isokinetic dynamometer, at a speed of 90º/s. Self-reported symptoms and disability were assessed using the WOMAC questionnaire. Spearman's correlation coefficient was used to test the relationship between the dependent variables (three subscales of WOMAC questionnaire) and the independent variables (average knee extensor peak torque). We found a strong negative correlation between the concentric extensor torque and pain (r=-0.7, p<0.001) and a moderate and negative correlation among the concentric extensor torque and stiffness (r=-0.62, p=0.002) and physical function (r=-0.54, p=0.011). Eccentric extensor torque presented a moderate and negative correlation with the three subscales of the WOMAC (r=-0.40 to 0.69, p<0.05). The concentric and eccentric knee extensor torque is significantly correlated with self-report symptoms of patients in initial stages of knee OA. Therefore, the strengthening of the quadriceps muscles, through concentric and eccentric exercise is indicated for these patients in order to minimize these symptoms.

Kinesio Taping® does not alter neuromuscular performance of femoral quadriceps or lower limb function in healthy subjects: Randomized, blind, controlled, clinical trial

The aim of this study was to analyze the immediate effects of applying Kinesio Taping® (KT) on the neuromuscular performance of femoral quadriceps, postural balance and lower limb function in healthy subjects. This is a randomized, blind, controlled, clinical trial, where sixty female volunteers (age: 23.3 ± 2.5 years; BMI: 22.2 ± 2.1 kg/m2) were randomly assigned to three groups of 20 subjects each: control (10 min at rest); nonelastic adhesive tape (application over the rectus femoris, vastus lateralis and vastus medialis muscles); and KT (KT application over the same muscles). All individuals were assessed for single and triple hops, postural balance (by baropodometry), peak concentric and eccentric torque and electromyographic activity of vastus lateralis, before and after interventions. No significant differences in electromyographic activity of the VL or concentric and eccentric knee peak torque were recorded, between groups and initial and final assessment in any of the three groups. We also observed no significant alteration in single and triple-hop distance and one-footed static balance between the three groups. Application of KT to RF, VL and VM muscles did not significantly change lower limb function, postural balance, knee extensor peak torque or electromyographic activity of VL muscle in healthy women.

Effects of repeated bouts of squatting exercise on sub-maximal endurance running performance

It is well established that exercise-induced muscle damage (EIMD) has a detrimental effect on endurance exercise performed in the days that follow. However, it is unknown whether such effects remain after a repeated bout of EIMD. Therefore, the purpose of this study was to examine the effects of repeated bouts of muscle-damaging exercise on sub-maximal running exercise. Nine male participants completed baseline measurements associated with a sub-maximal running bout at lactate turn point. These measurements were repeated 24-48 h after EIMD, comprising 100 squats (10 sets of 10 at 80 % body mass). Two weeks later, when symptoms from the first bout of EIMD had dissipated, all procedures performed at baseline were repeated. Results revealed significant increases in muscle soreness and creatine kinase activity and decreases in peak knee extensor torque and vertical jump performance at 24-48 h after the initial bout of EIMD. However, after the repeated bout, symptoms of EIMD were reduced from baseline at 24-48 h. Significant increases in oxygen uptake (.VO2), minute ventilation (.VE), blood lactate ([BLa]), rating of perceived exertion (RPE), stride frequency and decreases in stride length were observed during sub-maximal running at 24-48 h following the initial bout of EIMD. However, following the repeated bout of EIMD, .VO2, .VE, [BLa], RPE and stride pattern responses during sub-maximal running remained unchanged from baseline at all time points. These findings confirm that a single resistance session protects skeletal muscle against the detrimental effects of EIMD on sub-maximal running endurance exercise.