Gender-specific knee extensor torque, flexor torque, and muscle fatigue responses during maximal effort contractions

Abstract

The purpose of this study was to examine gender differences in knee extensor and flexor peak torque, work, power, and muscle fatigue during maximal effort isokinetic contractions. Subjects included 19 healthy male and 20 healthy female volunteers. Following a dynamic warm-up period, subjects performed 30 reciprocal, concentric maximal knee extension and flexion contractions at a pre-set angular velocity of 3.14 rad x s(-1) on the Biodex Isokinetic Dynamometer. Values for knee extensor peak torque, work, and power were calculated for each repetition over an angular displacement of 1.05 rad for each repetition. The single highest repetition value for knee extensor and flexor peak torque, work, and power was then calculated relative to body mass (N x m x kg(-1), J x kg(-1), W x kg(-1)) and allometric-scaled (N x m x kg(-) (n), J x kg(-) (n), W x kg(-) (n)) units. The allometric-scaled units were derived from a log-log transformation and linear regression analysis to calculate the exponent to which body mass is raised. The rate of quadriceps femoris muscle fatigue was calculated as the decline in each isokinetic variable by the linear slope from the single highest repetition value through the 30th repetition, and by two different fatigue indexes. The results demonstrate higher knee extension and flexion peak torque, work, and power in absolute, relative, and allometric-scaled units for males compared to females. Males exhibited higher fatigue rates for both muscle groups of each isokinetic variable than females, as described by the slope and the fatigue index, except when adjusted for peak values via analysis of covariance. The findings suggest that during maximal-effort muscle contractions, males exhibit a higher susceptibility to muscle fatigue than females, a phenomenon that may be related to an inherent ability to generate higher knee extensor and flexor torque.

Influence of cryotherapy on balance and joint position sense in healthy subjects: randomized clinical trial.

“…The following inclusion criteria were considered: aged between 18 and 28, recreationally physically active (22) , integrity of the knee joint of the dominant lower limb, absence of musculoskeletal injury history of the lower limbs in the last six months, no history of lower limb surgery , no neurological deficits, no uncorrected visual and/or hearing deficits, and no allergy to cold. Volunteers who reported pain during the procedures for data collection or those that fail to implement the assessment procedures in the correct manner were excluded from the study.…”

Analysis of acceleration time of ankle in long-distance runners and triathletes

“…Before the test, participants did a warm-up exercise on an ergometric bicycle for five minutes, consisting of submaximal effort bicycle (comfortable loading and cadence that would not cause fatigue). 16 Following this, the subjects performed the tests, which consisted of stretching of the dorsiflexor and plantar flexor muscles of the feet in three sets of 30 seconds. 19,20 Before the tests were started, the isokinetic dynamometer was calibrated and positioned.…”

“…Control group (GC) -physical activity practice with the aim of maintaining aerobic physical conditioning, without any regular sports training aims; frequency of this physical activity from two to three times a week (2.7 ± 0.4 (homogenous over the three months prior to the evaluations). 16 The exclusion criteria common to the three groups were the following: presence of ankle joint injuries over the last six months, injury defined as an event that put the athlete out of the sport for 24 hours or more consecutively; 17 presence of pain during the period when the tests were being done. Table 1 describes the anthropometric data on the individuals of the three groups (weight, height and age).…”

Fadiga muscular entre séries de exercícios isocinéticos em mulheres jovens

“…Vários fatores como a massa muscular, o tipo de fibra muscular e a ativação muscular específica podem influenciar a fadiga (KENT-BRAUN et al, 2002). O gênero, por sua vez, é um fator inerente que pode também influenciar a fadiga muscular (PINCIVERO et al, 2003).…”