Flexion Peak Torque Research Articles

Relationship Between Two Upper Extremity Functional Performance Tests And Shoulder And Trunk Muscle Strength

In contrast to the lower extremity, data concerning upper extremity (UE) functional performance tests (FPT) are more limited. PURPOSE: To determine the relationship of two UEFPT with shoulder and trunk flexion peak torque (PT) and anthropometric characteristics. METHODS: In a random order, 26 healthy, physically active men (1.80±.07m, 80.9±10.1kg 24.9±2.7yrs) completed two UE FPT and concentric isokinetic assessments for shoulder internal rotation (IR) and trunk flexion during a single session. All testing was performed using the dominant arm. The UE FPT consisted of the Underkofler Softball Throw for Distance (USTD) and a one-arm seated shot put throw (SPT). Following two submaximal and one maximal effort warm-up trials, the average of three maximum effort trials of each UE FPT were used for data analysis. Shoulder IR PT (60°/s, 180°/s, 300°/s) and trunk flexion PT (60°/s, 120°/s) were calculated across five trials at each speed. Height, mass and body mass index (BMI) were also measured. Correlational analyses were conducted between UE FPT performance, shoulder PT and trunk flexion PT, and anthropometric characteristics. RESULTS: No significant relationships were revealed with the anthropometric characteristics or trunk flexion PT; however shoulder IR PT at all speeds were moderately related to both UE FPT.TABLECONCLUSION: Normalization to body mass, height and BMI do not appear to be necessary for either UE FPT. The USTD and SPT tests appear to moderately reflect shoulder IR force production capabilities. The lack of significant relationships with trunk flexion PT may be a function of the UE FPT requiring coupled trunk flexion and rotation simultaneously. These data support using the USTD and SPT tests as indicators of shoulder function.

Dietary Protease Supplementation Attenuates Eccentric-exercise Induced Force Production Decrements By Regulating Leukocyte Activity

Dietary protease supplementation has been purported to reduce the damaging effects of eccentric exercise and accelerate recovery of muscle function, possibly by regulating local inflammation. PURPOSE: To determine the effectiveness of prophylactic protease supplementation in attenuating eccentric-exercise induced skeletal muscle damage and inflammation. METHODS: Following standard physical and hemodynamic assessment subjects donated fasting venous blood samples. Subjects then performed isokinetic extension/flexion of the quadriceps group on a Biodex isokinetic dynamometer at 60°/s, followed by VO2max testing. Subjects were randomly assigned to consume 5.83g daily of either a cellulose placebo (N= 15; 22.27+3.33 yr, 71.17+2.91 in, 179.4+24.05 lb, 50.55+5.66 ml/kg/min) or a proteolytic supplement containing fungal proteases, bromelain, and papain (N= 14; 22.85+5.9 yr, 70.0+2.67 in, 173.11+29.94 lb, 49.69+6.15 ml/kg/min) for a period of 21 days. Following the supplementation period, subjects donated blood samples prior to performing a 45 minute downhill (-17.5%) treadmill protocol at 60% of VO2max. An additional 4 blood draws and 3 muscle function tests were performed over the next 48h. Blood was analyzed using standard hematology and clinical chemistry, ELISA, and bead-array. Blood data were analyzed using MANOVA with repeated measures, while Biodex data were analyzed using MANOVA on %D values. RESULTS: Significant group differences (T1-T3, p= 0.033; T1-T4, p= 0.043) and another strong trend (T1-3h, p= 0.055) were observed for flexion peak torque %D at 60°/s. No significant differences were observed for extension. Following eccentric exercise, muscle force in the protease group actually increased (T1-3h: 4.73%, T1-T3: 3.01%, T1-T4: 6.44%), while the placebo group experienced significant force decrements (T1-3h: -19.54%, T1-T3: -27.94%, T1-T4: -25.87%). Significant group x time interactions (p < 0.05) for the protease group were observed with increases in circulating eosinophils, basophils, and decreases in serum COX2, IL-6, and IL-12. CONCLUSION: Protease supplementation appears to attenuate muscle strength loss following eccentric exercise by altering leukocyte activity and inflammatory responses. Funded by Transformation Enzyme Corp. (Houston, TX) & ACSM Texas Chapter.

An Optimal Interset Rest Period For Strength Recovery During A Common Isokinetic Test

Isokinetic testing has been used in rehabilitation settings on a regular basis, yet there is a lack of consistency in rest period usage among protocols. PURPOSE: The purpose of this study was to establish an optimal rest period that would allow reproducibility of strength during a common isokinetic strength-test. METHOD: Twenty-seven healthy college-aged males (23 ± 3.8 yrs and body weight 79.61 ± 11.11 kg) underwent isokinetic strength testing (Cybex NORM) of the knee flexors and extensors, to determine peak torque at 60, 180 and 300 deg/sec, respectively. Work:rest ratios of 1:3, 1:8 and 1:12 were counterbalanced between sets. Subjects were tested on five separate occasions; two familiarization sessions and three experimental sessions. A 3 X 3 repeated measures ANOVA was used to analyze the data with a <.05. RESULTS: There was no significant interaction of rest and velocity for either knee extension or knee flexion peak torque. Secondly, there was no significant difference in either knee extension or knee flexion peak torque when comparing work:rest ratios. However, there was a significant difference in peak torque between velocities: knee extension peak torque (F= 498.238, p <.05), knee flexion peak torque (F=1048.166, p <.05). CONCLUSION: These findings suggest that a 1:3 work:rest ratio is sufficient during a common isokinetic strength test. Furthermore, the lack of significant differences among work:rest ratios suggests the need for more research in this area to better understand the impact of rest duration on strength performance.

Ankle morbidity after autogenous Achilles tendon harvesting for anterior cruciate ligament reconstruction

Although several alternative autografts with reduced morbidity of harvest site have been introduced, no donor site is free of morbidity concerns. The authors report on ankle status after autogenous Achilles tendon harvesting with a minimum 10-year follow-up. From October 1994 to October 1996, a consecutive series of 47 ankles underwent harvesting of the medial third or half of the ipsilateral autogenous Achilles tendon for primary anterior cruciate ligament reconstruction. Donor site statuses were evaluated using a modified Thermann's scale. Postoperative isokinetic muscle strength testing was performed, and magnetic resonance images of donor sites were available for selected patients. Thirty-three ankles in the 32 patients were followed for more than 10 years. There were 27 men (84%) and 5 women (16%) with a mean age of 31 years (range 16-52 years) at the time of surgery. The mean duration of follow-up was 12 years and 1 month (range 10 years and 5 months to 13 years and 4 months). Mean postoperative modified Thermann's scale score was 87 (range 45-95; SD 14.3). Twenty-five (76%) ankles achieved very good or good results. A slight decrease in calf circumference <1 cm was seen in the ten ankles, 1-2 cm in the four ankles. Nine ankles were mildly hypersensitive to meteorological changes. Peak torque of ankle plantar flexion was slightly lower on the index limb at both velocities in nine selected patients who carried out performance tests. However, there were no significant differences (5.2% at 30 degrees /s and 2.7% at 120 degrees /s, P = n.s. and P = n.s.). Of the 12 available follow-up magnetic resonance images, the average cross-sectional area of the remaining tendon was 82.01 mm(2) (range 69.05-107.35; SD 10.3), and their average thickness was 7.4 mm (range 6-10.35; SD 1.1). After a minimum 10-year follow-up, the harvesting of autogenous Achilles tendons was not found to significantly jeopardize ankle status. However, it also could not be independent of donor morbidity as an alternative. The level of evidence was retrospective level IV, as a therapeutic study.

Acute Enhancement of Lower-Extremity Dynamic Strength and Flexibility with Whole-Body Vibration

The purpose of this investigation was to examine the acute effects of whole-body vibration (WBV) on muscular strength, flexibility, and heart rate (HR). Twenty adults (10 men, 10 women) untrained to WBV participated in the study. All subjects completed assessment of lower-extremity isokinetic torque, flexibility, and HR immediately before and after 6 minutes of WBV and 6 minutes of leg cycling ergometry (CYL), in randomized order. During WBV, subjects stood upright on a vibration platform for a total of 6 minutes. Vibration frequency was gradually increased during the first minute to a frequency of 26 Hz, which was maintained for the remaining 5 minutes. During CYL, power output was gradually increased to 50 W during the first minute and maintained at that power output for the remaining 5 minutes. Lower-extremity flexibility was determined using the sit-and-reach box test. Peak and average isokinetic torque of knee extension and flexion were measured by means of a motor-driven dynamometer with velocity fixed at 120 degrees .s. Change scores for the outcome measures were compared between treatments using Student's paired t-tests. Analysis revealed significantly greater HR acceleration with CYL (24.7 bpm) than after WBV (15.8 bpm). The increase of sit-and-reach scores after WBV (4.7 cm) was statistically greater (p < 0.05) than after CYL (0.8 cm). After WBV, increases in peak and average isokinetic torque of knee extension, 7.7% and 9.6%, were statistically greater than after CYL (p < 0.05). Average torque of knee flexion also increased more with WBV (+7.8%) than with CYL (-1.5%) (p < 0.05). The findings of this study indicate that short-term WBV standing elicits acute enhancements of lower-extremity muscular torque and flexibility, suggesting the application of this technology as a preparatory activity before more intense exercise.

Evaluation of knee peak torque in athletic and sedentary children

We examined the influence of sex, level of activity, and pubertal status on knee extension (Ext) and flexion (Fl) peak torque (PT) in children using an allometric modeling approach. A total of 140 students (67 males, 73 females) aged 12/13 years were enrolled from a Hong Kong junior high school, whose curricula were based on physical education (n=69) or arts (n=71). Isokinetic concentric Ext and Fl PT of the dominant leg was assessed at 1.04 rad/sec using a Cybex II+ dynamometer and body mass, stature, and pubertal stage were measured. A repeated-measures ANOVA test was performed on absolute PT data with muscle action (Ext and Fl) as a within-subject factor and between-subject factors including sex, group, and pubertal stage. To assess the effects on body size-adjusted PT, linear ANCOVA and log-linear ANCOVA techniques were used with body mass and stature taken as covariates. Peak torque was significantly greater in boys compared to girls, and in the physical education group compared to the arts group. When PT was adjusted for differences in body size, there was a greater difference in PT between girls in the two groups compared to boys, and there was a significant effect of pubertal stage. Allometric analysis showed that PT was influenced more by stature than body mass, and PT increased at a greater rate than body size (both p<0.01). There may be a need for a physical activity intervention in sedentary 12/13 year old girls. Peak torque appears to increase disproportionately to body size. This may result from a greater increase in leg muscle mass relative to body mass.

COMPARISON BETWEEN THE RESULTS ACHIEVED IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH TWO KINDS OF AUTOLOGOUS GRAFTS: PATELLAR TENDON VERSUS SEMITENDINOUS AND GRACILIS

Objective: this study aims to compare the arthrometric and isokinetic examination results from two types of autologous grafts: the central third of the patellar ligament and a graft formed by the tendons of the semitendinosus and gracilis muscles, within the same rehabilitation protocol, six months after the surgery. Methods: the results from examinations carried out on 63 patients were analyzed. These patients were divided in two groups: one group of 30 patients who received a patellar tendon graft and another group of 33 patients who received a graft from the tendons of the semitendinosus and gracilis muscles. Both the grafts were attached in the same way, with Endobutton™ for suspensory fixation to the femur and a bioabsorbable interference screw for fixation in the tibial tunnel. Results: arthrometry 30 did not present any statistical difference between the two study groups. On the other hand, the isokinetic evaluation showed that the patellar tendon group had a larger mean peak torque of flexion and greater extension deficit, while the semitendinosus/gracilis group had a better mean flexion/extension ratio and greater percentage of flexion deficit. There was no statistically significant difference between the groups when measuring peak torque extension. Conclusion: therefore, when the patellar tendon was used, there was greater extensor deficit and, when the semitendinosus/gracilis tendons were used, there was greater flexor deficit.

8주간 등속성운동이 여성 전방십자인대 상해환자의 무릎관절 회전력에 미치는 영향

The purpose of this study was to examine the effect of 8weeks isokinetic exercise on torque variables of knee joint in anterior cruciate ligament patient women. The subjects of the study were 8 female attached who registered patient at muscular-joint function clinic of the H hospital. The group were divided into two group; the experimental group as injured side leg and control group as non-injured side leg. Isokinetic knee joint exercise employed Kin-Com (U.S.A) to measure peak torque(PT), PT%BW, average power, average%BW, and recover ratio. The results of this study were follows; After 8weeks of 60°/sec exercise in PT, PT%BW were significantly increased in non-injured side leg group(p.05) and it was in flexion then in extension recovery ratio(p.05). After 8weeks of 180°/sec exercise in average, average%BW were significantly increased in non-injured side leg group(p.05) and it was in flexion then in extension recovery ratio(p.05). When PT-angle in 30°/sec load of pre operation becomes smaller it can correlation in flexion PT%BW, average power%BW, these were not correlation in extension(p.01).

Relationship between muscle volume and muscle torque of the hamstrings after anterior cruciate ligament reconstruction

The muscle torque per unit volume of the hamstrings on the injured and uninjured sides in patients with ACL reconstruction were compared with participants with no history of knee injury to examine whether a similar mechanism leading to quadriceps weakness exists in the hamstrings of these patients. The study population consisted of 18 and 52 patients at ≤6 and 12 months after ACL reconstruction, respectively, and 35 healthy controls. The hamstring volume was measured on MRI. To identify the muscle torque per unit volume, the peak torque of knee flexion was divided by the hamstring volume. Most muscle torque per unit volume indexes were not significantly different between the patients at ≤6 months (injured side: 0.133 ± 0.03 N m/cm 3, 60°/s; 0.107 ± 0.03 N m/cm 3, 180°/s; uninjured side: 0.139 ± 0.02 N m/cm 3, 60°/s; 0.107 ± 0.02 N m/cm 3, 180°/s) and controls (0.170 ± 0.05 N m/cm 3, 60°/s; 0.121 ± 0.05 N m/cm 3, 180°/s). However, the muscle torque per unit volume of patients at 12 months in both injured (0.118 ± 0.03 N m/cm 3, 60°/s; 0.092 ± 0.02 N m/cm 3, 180°/s) and uninjured sides (0.120 ± 0.03 N m/cm 3 at 60°/s; 0.094 ± 0.02 N m/cm 3, 180°/s) were significantly lower than those of controls ( P < 0.01). We found no evidence of recruitment disorder in the hamstrings of the patients. The results of this study indicated that the mechanism of muscle weakness of the hamstrings after reconstruction was different from that of the quadriceps, although the precise mechanism remains to be determined.

Isokinetic quadriceps and hamstring muscle strength and knee function 5 years after anterior cruciate ligament reconstruction: comparison between bone-patellar tendon-bone and hamstring tendon autografts

Existing clinical studies have not proven which graft is to be preferred in anterior cruciate ligament (ACL) reconstruction. In recent years, bone-patellar tendon-bone and hamstring tendons have been the most frequently used graft types. Muscle strength deficit is one of the consequences after ACL reconstruction. The aim of this study was to evaluate possible differences in hamstring and quadriceps muscle strength and knee function 5 years after ACL reconstruction between the BPTB and the STG groups. The study group consisted of 288 patients (132 women, 156 men) with a unilateral ACL rupture who had received a BPTB (175 patients) or STG (113 patients) ACL reconstruction. Lower extremity concentric isokinetic peak extension and flexion torques were assessed at the angular velocities of 60 degrees /s and 180 degrees /s. The International Knee Documentation Committee (IKDC), the Tegner activity level, the Lysholm knee and the Kujala patellofemoral scores were also collected. Isokinetic quadriceps peak torque (percentage of the contralateral side) was 3.9% higher in the STG group than in the BPTB group at the velocity of 60 degrees /s and 3.2% higher at the velocity of 180 degrees /s and the isokinetic hamstring peak torque 2% higher in the BPTB group than in the STG group at the velocity of 60 degrees /s and 2.5% higher at the velocity of 180 degrees /s. In both groups the subjects had weaker quadriceps and hamstring muscle strength in the injured extremity compared with the uninjured one. In the single-leg hop test (according to the IKDC recommendations) there was a statistically significant difference (P = 0.040) between the groups. In the STG group, 68% of the patients had the single-leg hop ratio (injured vs. uninjured extremity) > or =90%, 31% of the patients 75-89% and 1% of the patients <75%, while in the BPTB group the corresponding percentages were 72, 21 and 7%. However, no statistically significant differences in clinical outcome were found between the groups as determined by the IKDC, Tegner activity level, Lysholm knee and Kujala patellofemoral scores.

Resistance Training for Medial Compartment Knee Osteoarthritis and Malalignment

1) To evaluate the effects of a 12-wk high-intensity knee extensor and flexor resistance training program on strength, pain, and adherence in patients with advanced knee osteoarthritis and varus malalignment and 2) to generate pilot data for change in dynamic knee joint load, patent-reported outcomes, and self-efficacy after training. Fourteen patients (48.35 +/- 6.51 yr) with radiographically confirmed medial compartment knee osteoarthritis and varus malalignment of the lower limb were recruited from a surgical waiting list for high tibial osteotomy. Participants completed a high-intensity isokinetic resistance training program three times per week for 12 wk. Knee extensor and flexor strength were assessed every third week, whereas pain and adherence were recorded at every training session. The external knee adduction moment during the gait, the 6-min-walk test, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Arthritis Self-Efficacy Scale (ASES) were also evaluated before and after training. Significant improvements in knee extensor and flexor strength were observed without increases in pain during or after training. Adherence to the high-intensity program was high. No significant changes were observed for dynamic knee joint load or the KOOS. There was a significant increase in the function subscale of the ASES only. These findings suggest that patients with advanced knee osteoarthritis and malalignment can experience substantial gains in strength after a high-intensity resistance training program without concomitant increases in pain, adverse events, or compromised adherence. These findings provide support for future clinical trials with longer-term outcomes.

Effects of Stretching on Peak Torque and the H : Q Ratio

The purpose of the present study was to examine the acute effects of hamstring and calf stretching on leg extension and flexion peak torque (PT) and the hamstrings-to-quadriceps (H : Q) ratio during maximal, concentric isokinetic muscle actions at 60, 180, and 300 degrees . s (-1) in women. Thirteen women (mean age +/- SD = 20.8 +/- 1.8 yrs; height = 163.0 +/- 5.7 cm; mass = 64.0 +/- 8.3 kg) performed 3 maximal concentric isokinetic leg extension and flexion muscle actions at 3 randomly ordered angular velocities (60, 180, and 300 degrees . s (-1)) before and after a bout of static stretching. The stretching protocol consisted of 1 unassisted and 3 assisted static stretching exercises designed to stretch the posterior muscles of the thigh and leg. Four repetitions of each stretch were held for 30 s with 20 s rest between repetitions. The results indicated that leg flexion PT decreased from pre- to post-stretching (34.9 +/- 3.5 and 32.4 +/- 3.2 Nm, respectively) collapsed across velocity. However, no other changes were observed from pre- to post-stretching for leg extension PT (78.5 +/- 5.9 and 77.8 +/- 5.5 Nm, respectively) and the H : Q ratio (0.47 +/- 0.04 and 0.44 +/- 0.03, respectively). Our findings suggested that despite the stretching-induced decreases in leg flexion PT, leg extension PT and the H : Q ratios were unaltered by the stretching.

Acute Effects of Static Stretching on Leg Extension and Flexion Isokinetic Peak Torque and the Hamstring-to- Quadriceps Ratio

INTRODUCTION: Low hamstring-to-quadriceps isokinetic peak torque ratios have been associated with an increased risk of injury. Since stretching may decrease isokinetic peak torque, it is possible that hamstring stretching may adversely affect the hamstrings:quadriceps (H:Q) ratio. PURPOSE: To examine the acute effects of traditional hamstring and calf static stretching on leg flexion and leg extension isokinetic peak torque (PT) and the H:Q ratios at 60, 180, and 300° s−1. METHODS: Six men (mean ± SD age = 24.0 ± 6.3 yrs; body mass = 89.3 ± 13.1 kg; height = 177.1 ± 6.6 cm) and six women (21.7 ± 1.2 yrs; 62.2 ± 5.9 kg; 165.9 ± 6.2 cm) performed three maximal voluntary unilateral isokinetic leg extension and flexion muscle actions at three randomly ordered angular velocities (60, 180, and 300°·s−1) before and after a bout of hamstring and calf static stretching. The stretching protocol consisted of 1 unassisted and 3 assisted static stretching exercises designed to stretch the posterior muscles of the thigh and leg. Four repetitions of each stretch were held for 30 s with 20-s rest between repetitions. Three separate three-way mixed factorial ANOVAs (time x velocity x gender) were used to analyze the leg extension and flexion PT as well as the H:Q ratio data. RESULTS: There were no interactions (p > 0.05) for leg extension PT or H:Q ratio, however, the main effects for velocity (p ≤ 0.05) indicated that PT decreased and H:Q ratio increased from 60 to 300°·s−1. There was a three-way interaction (time x velocity x gender; p ≤ 0.05) for leg flexion PT. Post-hoc t-tests indicated that leg flexion PT decreased (p ≤ 0.05; 11.5%) from pre- to post-stretching at 60°·s−1 for the women. However, no other stretching-related changes were observed. CONCLUSIONS: Our findings indicated that there were velocity-specific, stretchinginduced decreases in leg flexor isokinetic PT at 60°·s−1, but not 180 and 300°·s−1, for the women, but not the men. However, this decrease was not sufficient to alter the H:Q ratio. In addition, the stretching did not affect leg extension (antagonist) strength. These findings suggested that static stretching of the hamstrings and calf muscles may not adversely affect the H:Q ratio, despite transient decreases in leg flexor strength at 60°·s−1 in women.

Relationship Between Thigh Muscle Strength, Competitive Exercise, and BMD in Elderly Athletes and Controls

PURPOSE: This study investigated the relationship between competitive exercise, quadriceps and hamstring strength and regional and total body bone mineral density (BMD) in elite senior athletes and healthy elderly controls. METHODS: The 183 participants included 104 athletes of the National Senior Games (72.6±6.4 yrs, 72.6±13.5 kg, 168.7±8.6 cm) and 79 healthy controls (75.4±5.6 yrs, 79.5±11.7 kg, 170.8±25.5 cm). Three 5-sec trials of isometric knee flexion and extension were collected (100 Hz) using a load-cell affixed to a custom apparatus which held the knee at 45 degrees. Hip, radius, spine, and total body BMD were measured with a Hologic 4500A DXA scanner. For each of the 4 BMD sites assessed, multiple linear regression analysis was performed in four steps (α = 0.10). First, age, gender, and bodyweight were entered as a block into the statistical model to determine their correlation with the BMD variable. Secondly, group (athlete, control) was added. Subsequently, extension flexion peak torque was entered into the model. Lastly, because extension and flexion peak torque are highly correlated (R=0.67), extension peak torque was removed and flexion peak torque was added to the model. RESULTS: The variables of gender, age, and bodyweight explained 26%, 52%, 24%, and 33% of the variance in hip, radius, spine, and total body BMD, respectively. The inclusion of the group variable did not add significantly to any the model. The addition of extension peak torque into the model resulted in an increase of explained variance of 1.5% in hip BMD (p = 0.07). It was not related to BMD at any other site. Flexion peak was not related to BMD at any of the sites measured. CONCLUSIONS: Age, gender, and body weight were predictive of BMD at the hip, radius, spine, and in the total body. Highly competitive exercise was not related to BMD. Hip BMD was correlated with quadriceps strength after controlling for the effects of competitive exercise, gender, age, and bodyweight.

Vitamin D Concentrations and Neuromuscular Function in Patients with Crohn's Disease

PURPOSE: The purpose of this study was to determine if patients with Crohn's disease have low serum vitamin D 25(OH)D and neuromuscular function, as evidenced by muscle strength, muscle fatigue, nerve function, and quality of health. METHODS: 19 subjects with Crohn's disease (9 M/10F, 44.2+10.3 yrs, 168.5+15.5 cm, and 77.2+19.5 kg ), with at least one small bowel resection were tested, as were 19 age and gender matched controls (44.21+10.41 yrs, 173.25+11.5 cm, and 80.5+17.3 kg). Serum vitamin D was measured via a blood draw. Isometric thigh muscle strength at 45° of knee extension were measured using a load cell in a custom device. Fatigue rates of the rectus femoris and vastus lateralis were assessed via EMG. Peroneal nerve latency and magnitude were measured with a Brevio® NCS-Monitor. The total physical score and total mental score from the SF-36 were also gathered to assess quality of health. A two factor ANOVA (group x gender) was performed on each of the measured variables (alpha = 0.05). RESULTS: No difference was found in the serum vitamin D concentrations between group (p=0.32) and gender (p=0.98). Quadriceps and hamstring peak torque (Nm/BW) was greater in the control group (p=0.039 and p=0.001, respectively). The males also demonstrated significantly greater knee extension (p=0.037) and flexion (p=0.047) peak torque. The fatigue rates for the rectus femoris and the vastus lateralis were not different between groups or genders. No group or gender differences were noted in nerve function or either quality of health measure of the SF-36. CONCLUSIONS: Low levels of serum vitamin D are known to negatively affect neuromuscular function. Although patients with Crohn's disease report muscle pain and weakness, they were not found to be low in vitamin D when compared to a healthy control group. Thigh muscle weakness was found for the Crohn's patients in the current study; however, this weakness is not believed to be related to low serum vitamin D levels. Further studies are required to identify the exact mechanisms of the decreased strength experienced by Crohn's patients.

Effect of Magnesium Supplementation in Isokinetic Knee-Flexion in Elite Volleyball Players

Magnesium is involved in various processes that affect muscle function including energy production and electrolyte balance. The relationship between magnesium status and exercise has received significant attention in the past decade, and supplementation, in order to improve performance, is a discussed subject. PURPOSE: To evaluate if magnesium supplementation improves muscle strength in well trained athletes. METHODS: Nine male athletes (23+2yrs), from a professional volleyball adult team, were randomly assigned to two experimental groups, double-blind: magnesium supplementation (500mg magnesium oxide capsules per day, five athletes) and control (500mg maltodextrin capsules per day, four athletes) during a four-week period. At t=0 and t=30days the athletes performed maximal eccentric isokinetic muscle actions of the dominant and nondominant knee extensor muscles at 60 degrees x s(-1) on a isokinetic dynamometer (Biodex). RESULTS: After the experimental period the supplemented group had left and right knee flexion peak torque greater than the control (196+19 vs. 170+13N·m, p=0.06) and (202+19 vs. 176+20N·m, p=0.11) respectively. CONCLUSIONS: The magnesium supplementation indicates an increase in the performance when evaluated for isokinetic knee-flexion. These differences had statistical significance (at the 0.15 level of significance), what recommends an evaluation with a larger sample. This study was supported by CNPq, grant nr. 142618/2005-5.

Neuromuscular Fatigue and Recovery in Elite Female Soccer

To investigate the time course of recovery from neuromuscular fatigue and some biochemical changes between two female soccer matches separated by an active or passive recovery regime. Countermovement jump (CMJ), sprint performance, maximal isokinetic knee flexion and extension, creatine kinase (CK), urea, uric acid, and perceived muscle soreness were measured in 17 elite female soccer players before, immediately after, 5, 21, 45, 51, and 69 h after a first match, and immediately after a second match. Eight players performed active recovery (submaximal cycling at 60% of HRpeak and low-intensity resistance training at < 50% 1RM) 22 and 46 h after the first match. In response to the first match, a significant decrease in sprint performance (-3.0 +/- 0.5%), CMJ (-4.4 +/- 0.8%), peak torque in knee extension (-7.1 +/- 1.9%) and flexion (-9.4 +/- 1.8%), and an increase in CK (+ 152 +/- 28%), urea (15 +/- 2), uric acid (+ 11 +/- 2%), and muscle soreness occurred. Sprint ability was first to return to baseline (5 h) followed by urea and uric acid (21 h), isokinetic knee extension (27 h) and flexion (51 h), CK, and muscle soreness (69 h), whereas CMJ was still reduced at the beginning of the second match. There were no significant differences in the recovery pattern between the active and passive recovery groups. The magnitude of the neuromuscular and biochemical changes after the second match was similar to that observed after the first match. The present study reveals differences in the recovery pattern of the various neuromuscular and biochemical parameters in response to a female soccer match. The active recovery had no effects on the recovery pattern of the four neuromuscular and three biochemical parameters.

Differences in Isometric Neck Muscle Strength Between Healthy Controls and Women With Chronic Neck Pain: The Use of a Reliable Measurement

Cagnie B, Cools A, De Loose V, Cambier D, Danneels L. Differences in isometric neck muscle strength between healthy controls and women with chronic neck pain: the use of a reliable measurement. Objectives To determine the intra- and interrater reliability of the Biodex isokinetic dynamometer to measure the maximal isometric strength of the cervical flexors and extensors, to develop an age- and sex-based normative database in a healthy population, and to evaluate the differences in neck strength between women with chronic neck pain and healthy controls. Design Cross-sectional. Setting Physical and rehabilitation medicine department. Participants Ninety-six healthy volunteers (4 age groups: 20–29, 30–39, 40–49, 50–59y; each consisting of 12 men and 12 women) and 30 women with chronic neck pain. Interventions Not applicable. Main Outcome Measures Peak isometric strength of the cervical muscles was tested for flexion and extension by using the Biodex isokinetic dynamometer. The intra- and interrater reliability of the protocol was evaluated in 12 volunteers. Results The reliability for strength was high for both flexion and extension (intraclass correlation coefficient, .92–.96). The mean peak torque for flexion and extension was significantly higher in men (24Nm, 36.4Nm, respectively) compared with women (16.6Nm, 26.5Nm, respectively) ( P<.001). Peak torque production for extension was significantly lower in the patient group (22.3Nm) compared with the healthy female control group (26.5Nm) ( P=.003). No significant differences in flexion strength between patient and female control group were found. Conclusions Results show a high degree of intra- and interrater reliability in measuring isometric neck muscle strength when using the Biodex isokinetic dynamometer. The use of normative data for neck strength when evaluating patients with neck disorders needs to take sex into account. The current study has shown that women with chronic neck pain have lower neck muscle strength in extension than the healthy female group.

Effect of Playing Football (Soccer) on Balance, Strength, and Quality of Life in Unilateral Below-Knee Amputees

To investigate the effect of playing football (soccer) on balance, muscle strength, locomotor capabilities, and health-related quality of life in subjects with unilateral below-knee amputation. Cross-sectional controlled study. Difference in KAT dynamic balance scores obtained 3 days after was statistically significant in the study group (P < 0.05) but not in the control group (P > 0.05). Differences in static balance test scores was statistically significant between the groups (P < 0.05) in favor of the study group. In isokinetic evaluation, differences in flexion and extension peak torque measures of the lower extremities were not statistically significant between the groups (P > 0.05). Differences in Houghton and Berg balance scales were not found statistically significant between the groups (P > 0.05). Differences in Locomotor Capabilities Index and in the SF-36 in physical functioning, physical role, pain, and emotional role between the groups were statistically significant (P < 0.05) in favor of the study group. Our results show that playing football may have positive effects on balance and health-related quality of life in unilateral below-knee amputees.

Valoración isocinética de la prótesis de rodilla tipo Scorpio PS

Introduction This study aims to evaluate muscle functionality in advanced osteoarthritis of the knee using isokinetics parameters and to analyze its evolution at 12 months of the implantation of a total knee arthroplasty (TKA). Furthermore, the results were also compared before and after surgery with the control group. Material and methods A sample of 16 patients with osteoarthritis, who could be treated with a TKA implant and a control group comparable in regards to gender sex, age and laterality, was studied. The study was conducted using a Cybex Norm dynamometer with concentric regime at speeds of 120° and 180°/ second. Results Significantly lower values in flexion ( peak torque 120°/second, peak torque 180°/second and set total work 120°/second) were observed in osteoarthritis patients in comparison with their respective control group. The values of the 180°/second ratio and the 180°/second flexion peak torque were significantly greater in the prosthetic group compared with the same group before surgery. The rest of the values obtained showed no statistically significant differences (p > 0.05). Discussion Patients with advanced osteoarthritis have a significant deficit in flexion but not in the extension regarding the control group. Those in whom a TKA Scorpio PS implant was done had no significant deficit of extension or flexion compared to the control group. The osteoarthritis subjects do not show significant differences regarding the extension compared to the same patients at 12-month.