COMPUTERIZED CYBEX TESTING OF ACL RECONSTRUCTIONS ASSESSING HAMSTRINGS PEAK TORQUE, TAE, TOTAL WORK AND AVERAGE POWER

1984 ◽  
Vol 16 (2) ◽  
pp. 204 ◽  
Author(s):  
J. A. Gould ◽  
G. J. Davies ◽  
D. E. Ross ◽  
M. J. Rowinski
Keyword(s):  
Average Power ◽  
Peak Torque ◽  
Total Work

scholarly journals Isokinetic evaluation of knee muscles in soccer players: discriminant analysis

2015 ◽  
Vol 21 (5) ◽  
pp. 364-368 ◽  
Author(s):  
Bruno Fles Mazuquin ◽  
Ligia Maxwell Pereira ◽  
Josilainne Marcelino Dias ◽  
João Pedro Batista Junior ◽  
Mônica Angélica Cardoso Silva ◽  
...  
Keyword(s):  
Human Performance ◽  
Average Power ◽  
Peak Torque ◽  
Knee Extension ◽  
Soccer Players ◽  
Total Work ◽  
Wilks Lambda ◽  
Discriminant Analyses ◽  
Definition Of ◽  
Flexion And Extension

ABSTRACT Introduction: Muscle activity in soccer players can be measured by isokinetic dynamometer, which is a reliable tool for assessing human performance. Objectives: To perform isokinetic analyses and to determine which variables differentiate the under-17 (U17) soccer category from the professional (PRO). Methods: Thirty four players were assessed (n=17 for each category). The isokinetic variables used for the knee extension-flexion analysis were: peak torque (Nm), total work (J), average power (W), angle of peak torque (deg.), agonist/ antagonist ratio (%), measured for three velocities (60°/s, 120°/s and 300°/s), with each series containing five repetitions. Three Wilks' Lambda discriminant analyses were performed, to identify which variables were more significant for the definition of each of the categories. Results: The discriminative variables at 60°/s in the PRO category were: extension peak torque, flexion total work, extension average power and agonist/antagonist ratio; and for the U17s were: extension total work, flexion peak torque and flexion average power. At 120°/s for the PRO category the discriminant variables were: flexion peak torque and extension average power; for the U17s they were: extension total work and flexion average power. Finally at 300°/s, the variables found in the PRO and U17 categories respectively were: extension average power and extension total work. Conclusion: Isokinetic variables for flexion and extension knee muscles were able to significantly discriminate between PRO and U17 soccer players.

scholarly journals KNEE BIOMECHANICS AND PHYSICAL PERFORMANCE;

2017 ◽  
Vol 24 (12) ◽  
pp. 1921-1926
Author(s):  
Hafiz Muhammad Manan Haider Khan ◽  
Tahir Masood
Keyword(s):  
Body Weight ◽  
Physical Performance ◽  
Martial Arts ◽  
Average Power ◽  
Weight Ratio ◽  
Peak Torque ◽  
Knee Biomechanics ◽  
Performance Tests ◽  
Total Work ◽  
Body Weight Ratio

Introduction: A 29-year old male athlete (body mass: 64 kg; height: 172 cm)sustained complete ACL rupture of the right knee. He was a martial-arts player and the injurywas repetitive, overuse in nature due to cyclic unilateral loading and unloading of the rightknee during training sessions. Rupture was diagnosed through detailed patient history, clinicalphysical examination and was confirmed through magnetic resonance imaging (MRI) of theright knee. Surgical reconstruction of the ACL was planned and a patellar tendon graft wasused. His baseline isokinetic data was recorded 4 months after the surgery. Objective: Thiscase study describes the effects of isokinetic strength training on knee biomechanics andphysical function of an ACL-reconstructed martial-arts athlete. Setting: Pakistan Sports BoardIslamabad. Study period: 40 days. Materials and Methods: Biodex System 3 Pro was used totrain the athlete for 15 sessions on alternate day basis. Average peak torque, average power,total work and peak torque to body weight ratio were recorded for hamstring and quadricepsbefore and after isokinetic rehabilitation. The athlete was positioned in the dynamometer withupright back while hip and knee were flexed to 90 degrees. Unilateral isokinetic contractionswere performed according to a premeditated exercise protocol. Both hamstring and quadricepswere tested isokinetically at five different movement speeds (30deg/sec, 90deg/sec, 150deg/sec, 210deg/sec, and 270deg/sec). Five contractions were performed at each speed duringboth knee flexion and extension. At baseline, average peak torque was higher at lower speedsfor both hamstring and quadriceps. Results: As a result of rehabilitation, average peak torquefor hamstring and quadriceps significantly improved at speeds of 150deg/sec and 90deg/secrespectively. Average power, peak torque to body weight ratio, total work was also improved forboth hamstring and quadriceps. Two physical performance tests - agility run test and verticaljump test - were used to assess the effects of training and both performance tests improved 51%and 100% respectively. Conclusion: Isokinetic training improved the strength of quadricepsand hamstring after ACL reconstruction. Hamstring muscle demonstrated greater traininginducedincrements in torque production compared to quadriceps at all contraction velocities.

scholarly journals Impaired muscle capacity of the hip and knee in individuals with isolated patellofemoral osteoarthritis: a cross-sectional study

2021 ◽  
Vol 12 ◽  
pp. 204062232110287
Author(s):  
Cristiano Carvalho ◽  
Fábio Viadanna Serrão ◽  
Letícia Mancini ◽  
Paula Regina Mendes da Silva Serrão
Keyword(s):  
Physical Functioning ◽  
Average Power ◽  
Peak Torque ◽  
Knee Extension ◽  
Cross Sectional Study ◽  
Healthy Controls ◽  
Patellofemoral Osteoarthritis ◽  
Total Work ◽  
Sectional Study ◽  
Cross Sectional

Aims: The aims of this study were to compare the capacity of the knee and hip muscles between individuals with and without isolated patellofemoral osteoarthritis (PFOA) and to evaluate the impact of PFOA on pain, stiffness, and physical function. Methods: This cross-sectional study evaluated muscle capacity of the hip and knee using an isokinetic dynamometer. The isokinetic variables used in the statistical analysis were peak torque, total work, and average power. Pain, stiffness, and physical function were assessed using questionnaires. Results: A total of 26 individuals participated in the study (13 with PFOA and 13 controls). The PFOA group exhibited lower peak torque, total work, and average power for knee extension and flexion in the concentric mode ( p ⩽ 0.01) as well as lower peak torque and total work for knee extension ( p ⩽ 0.005) and lower total work for knee flexion ( p = 0.05) in the eccentric mode. The PFOA group exhibited lower peak torque of the extensor, abductor, adductor, and internal rotator muscles of the hip ( p ⩽ 0.05), less total work of the abductor and adductor muscles ( p ⩽ 0.04), and lower average power of eccentric adduction of the hip ( p = 0.01) compared with the healthy controls. Compared with the control group, the PFOA group had a higher level of pain, stiffness, and compromised physical functioning self-reported ( p ⩽ 0.005). Conclusion: Participants with PFOA exhibited impairments regarding muscle capacity of the hip and knee, higher level of pain and stiffness as well as compromised physical functioning in comparison with healthy controls.

The Effects of Tourniquet Application in Total Knee Arthroplasty on the Recovery of Thigh Muscle Strength and Clinical Outcomes

2020 ◽  
Author(s):  
Omer Ayik ◽  
Mehmet Demirel ◽  
Fevzi Birisik ◽  
Ali Ersen ◽  
Halil I. Balci ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Muscle Strength ◽  
Clinical Outcomes ◽  
Knee Arthroplasty ◽  
Peak Torque ◽  
Thigh Muscle ◽  
Controlled Study ◽  
Total Work ◽  
Isokinetic Muscle Strength ◽  
Total Knee

AbstractThe present randomized controlled study aims to evaluate whether tourniquet application during total knee arthroplasty (TKA) has an effect on (1) thigh muscle strength (quadriceps and hamstring muscle strength) and (2) clinical outcomes (postoperative knee range of motion [ROM], postoperative pain level, and Knee Society Score [KSS]). The effects of tourniquet application during TKA were investigated in 65 patients randomly allocated to one of two groups: TKA with a tourniquet and TKA without a tourniquet. Patients in both groups were comparable in terms of the demographic and clinical data (p > 0.05 for age, number of patients, sex, radiographic gonarthrosis grade, American Society of Anesthesiologists [ASA] classification, and body mass index [BMI]). All patients in both groups were operated by the same surgeon using one type of prosthesis. Isokinetic muscle strength (peak torque and total work) of knee extensors (quadriceps) and flexors (hamstrings) was measured in Newton meters (Nm) using a CYBEX 350 isokinetic dynamometer (HUMAC/CYBEX 2009, Stoughton, MA). The combined KSS (knee score + function score), visual analog scale (VAS), and knee ROM were measured preoperatively and at 1 and 3 months postoperatively to evaluate clinical outcomes. There were no significant differences between the two groups in preoperative and postoperative values of isokinetic muscle strength (peak torque and total work) and aforementioned clinical outcomes (p < 0.05). The present study has shown that quadriceps strength and clinical outcomes were not improved in the early postoperative period (3 months) when a tourniquet was not used during TKA.

Dissociated time course between peak torque and total work recovery following bench press training in resistance trained men

2017 ◽  
Vol 179 ◽  
pp. 143-147 ◽  
Author(s):  
Diogo V. Ferreira ◽  
Paulo Gentil ◽  
João B. Ferreira-Junior ◽  
Saulo R.S. Soares ◽  
Lee E. Brown ◽  
...  
Keyword(s):  
Time Course ◽  
Bench Press ◽  
Peak Torque ◽  
Total Work ◽  
Work Recovery

scholarly journals Effect of Acute Ramadan Fasting on Muscle Function and Buffering System of Male Athletes

Healthcare ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 397
Author(s):  
Mohamad Fashi ◽  
Sajad Ahmadizad ◽  
Hadi Nobari ◽  
Jorge Pérez-Gómez ◽  
Rafael Oliveira ◽  
...  
Keyword(s):  
Muscle Function ◽  
Venous Blood ◽  
Average Power ◽  
Peak Torque ◽  
Buffering Capacity ◽  
Gas Analyzer ◽  
Borg Scale ◽  
Male Athletes ◽  
Ramadan Fasting ◽  
Blood Gas Analyzer

The aim of this study was to investigate the effect of acute Ramadan fasting (RF) on the muscle function and buffering system. Twelve male athletes with 8 years of professional sports experience (age, 23.2 ± 1.3 years, body mass index: 24.2 ± 2.2 kg/m2) participated in this study. The subjects were tested twice, 3 weeks after the beginning of RF and 2 weeks after the end RF. Muscle function, buffering capacity, and rating of perceived exertion (RPE) were measured during and after RF by using the Biodex isokinetic machine, blood gas analyzer, and RPE 6–20 Borg scale, respectively. Venous blood samples for pH and bicarbonate (HCO3−) were measured during and after RF by using the Biodex isokinetic machine, blood gas analyzer, and RPE 6–20 Borg scale, respectively. Venous blood samples for pH and bicarbonate (HCO3−) were taken immediately after 25 repetitions of isokinetic knee flexion and extension. Measures taken during isokinetic knee extension during RF were significantly lower than those after RF in extension peak torque (t = −4.72, p = 0.002), flexion peak torque (t = −3.80, p = 0.007), extension total work (t = −3.05, p = 0.019), extension average power (t = −4.20, p = 0.004), flexion average power (t = −3.37, p = 0.012), blood HCO3− (t = −2.02, p = 0.041), and RPE (Z = −1.69, p = 0.048). No influence of RF was found on the blood pH (t = 0.752, p = 0.476). RF has adverse effects on muscle function and buffering capacity in athletes. It seems that a low-carbohydrate substrate during RF impairs muscle performance and reduces the buffering capacity of the blood, leading to fatigue in athletes.

Power output and fatigue of human muscle in maximal cycling exercise

1983 ◽  
Vol 55 (1) ◽  
pp. 218-224 ◽  
Author(s):  
N. McCartney ◽  
G. J. Heigenhauser ◽  
N. L. Jones
Keyword(s):  
Power Output ◽  
Fiber Type ◽  
Average Power ◽  
Lactate Concentration ◽  
Peak Torque ◽  
Muscle Volume ◽  
Thigh Muscle ◽  
Peak Power Output ◽  
Maximal Power ◽  
Maximal Power Output

We studied maximal torque-velocity relationships and fatigue during short-term maximal exercise on a constant velocity cycle ergometer in 13 healthy male subjects. Maximum torque showed an inverse linear relationship to crank velocity between 60 and 160 rpm, and a direct relationship to thigh muscle volume measured by computerized tomography. Peak torque per liter thigh muscle volume (PT, N X ml-1) was related to crank velocity (CV, rpm) in the following equation: PT = 61.7 - 0.234 CV (r = 0.99). Peak power output was a parabolic function of crank velocity in individual subjects, but maximal power output was achieved at varying crank velocities in different subjects. Fiber type distribution was measured in the two subjects showing the greatest differences and demonstrated that a high proportion of type II fibers may be one factor associated with a high crank velocity for maximal power output. The decline in average power during 30 s of maximal effort was least at 60 rpm (23.7 +/- 4.6% of initial maximal power) and greatest at 140 rpm (58.7 +/- 6.5%). At 60 rpm the decline in power over 30 s was inversely related to maximal oxygen uptake (ml X min-1 X kg-1) (r = 0.69). Total work performed and plasma lactate concentration 3 min after completion of 30-s maximum effort were similar for each crank velocity.

scholarly journals Relationship between propulsive force of the arm, body composition and isokinetic muscle strength indicators in surfers

2018 ◽  
Vol 20 (3) ◽  
pp. 342-351
Author(s):  
Sidarta Oliveira Geber ◽  
Bruno Remígio Cavalcante ◽  
Antonio Henrique Germano-Soares ◽  
Raysa Catarina Cavalcante Figueiredo Montes ◽  
Arthur Henrique Oliveira Silva ◽  
...  
Keyword(s):  
Body Composition ◽  
Internal Rotation ◽  
Fat Mass ◽  
Muscle Function ◽  
External Rotation ◽  
Pearson Correlation ◽  
Peak Torque ◽  
Total Work ◽  
Propulsive Force ◽  
Teres Major

This study aimed to evaluate the potential relationship between body composition (percentage of fat mass (FM %), fat mass and lean mass), muscle function (e.g., muscles; deltoid side and front, pectoralis major and teres major) and the propulsive force of the arm (PFA). Sixteen competitive surfers (29.1 ± 7.3 years; 1.72 ± 0.06 m; 74.2 ± 1.4 kg) were assessed for height, body mass, body composition (dual-energy-DXA), muscle function and PFA. Pearson correlation analyses were used to verify the relationship between all variables. An inverse correlations were found between PFA and isokinetic parameters to 60o/s: external rotation (peak torque: r = -0.71; p = 0.014; total work: r = -0.75; p = 0.007; power: r = -0.72; p = 0.011) and internal rotation (peak torque: r = -0.61; p = 0.045; total work: r = -0.73; p = 0.010; power: r = -0.61; p = 0.045) and 300o/s: external rotation (peak torque: r = -0.79; p = 0.003; total work: r = -0.84; p<0,001; power: r = -0.81; p = 0.002) and internal rotation (peak torque: r = -0.69; p = 0.017; total work: r = -0.72; p = 0.011; power: r = -0.69; p = 0.017). There was no significant correlation between body composition components and PFA (p>0.05). Although correlations do not imply cause and effect, PFA is not correlated with body composition in surfers and these relationships are inversely related to the parameters of muscle function.

Differential effects of anesthetics on in vivo skeletal muscle contractile function in the mouse

1996 ◽  
Vol 80 (1) ◽  
pp. 332-340 ◽  
Author(s):  
C. P. Ingalls ◽  
G. L. Warren ◽  
D. A. Lowe ◽  
D. B. Boorstein ◽  
R. B. Armstrong
Keyword(s):  
Skeletal Muscle ◽  
Contractile Function ◽  
Average Power ◽  
Eccentric Contraction ◽  
Peak Torque ◽  
High Dose ◽  
Skeletal Muscle Function ◽  
Contractile Responses ◽  
Time Integral

The purpose of this study was to evaluate the effects of four anesthetic regimens on in vivo contractile function of mouse ankle dorsiflexor muscles. The torque-frequency and torque-velocity relationships were determined for the following anesthetics: fentanyl-droperidol and diazepam (F-d/d); ketamine and xylazine (K/x); pentobarbital sodium (Ps); and methoxyflurane (Mf). Mf, Ps, and F-d/d regimens resulted in comparable contractile responses at low doses, whereas K/x produced a relative depression in isometric contractile function as shown by a decrease in the torque-time integral at the 300-Hz stimulation frequency (-13.9%; P < 0.05). Moreover, K/x caused a shift to the left in the torque-frequency curve as indicated by increases in torque-time integrals at 25 and 50 Hz. Both Ps and F-d/d regimens exhibited dose-dependent effects during the isovelocity contractions. Ps significantly reduced work (-28.7%) and average power (-28.9%) at 800 degrees/s at the high dose. In contrast, F-d/d anesthesia resulted in increases in peak torque (16-20%) and work (15-18%) output at all eccentric contraction velocities at the high dose, whereas average power was increased only at -800 (17%) and -1,000 degrees/s (17%). In conclusion, commonly used anesthetic regimens can affect the contractile response in vivo; K/x and Ps yield smaller torque outputs, whereas Mf and F-d/d consistently produce larger contractile responses. Mf and F-d/d are recommended for use in studying skeletal muscle function in mice in vivo.

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