Isokinetic strength testing does not predict hamstring injury in Australian Rules footballers.

Abstract

Objective-To determine the relation of hamstring and quadriceps muscle strength and imbalance to hamstring injury using a prospective observational cohort study Method-A total of 102 senior male Australian Rules footballers aged 22.2 (3.6) years were tested at the start of a football season. Maximum voluntary concentric and eccentric torque of the hamstring and quadriceps muscles of both legs was assessed using a Kin-Com isokinetic dynamometer at angular velocities of 60 and 180 degrees/second. Twelve (11.8%) players sustained clinically diagnosed hamstring strains which caused them to miss one or more matches over the ensuing season. Results-There were no significant diVerences for any of the isokinetic variables comparing the injured and non-injured legs in players with unilateral hamstring strains (n = 9). Neither the injured nor the non-injured leg of injured players diVered from the mean of left and right legs in non-injured players for any isokinetic variable. The hamstring to opposite hamstring ratios also did not diVer between injured and non-injured players. A hamstring to opposite hamstring ratio of less than 0.90 and a hamstring to quadriceps ratio of less than 0.60 were not associated with an increased risk of hamstring injury. A significantly greater percentage of players who sustained a hamstring strain reported a history of hamstring strain compared with non-injured players (p = 0.02). However, this was not related to muscle weakness or imbalance. Conclusions-Isokinetic muscle strength testing was not able to directly discriminate Australian Rules football players at risk for a hamstring injury. (Br J Sports Med 1998;32:309-314)

Effects of sport type and angular velocity on hamstring to quadriceps strength ratio in adolescent female athletes

“…H:Q ratio increased from 69.6±11.8% at 60°/s to 76.7±13.5% at 180°/s and these results showed similarity with the values at 60 °/s (69%) and 180 °/s (73%) angular velocities reported by Bennell, et al (28)., Rosene et al evaluated the conventional H:Q ratios in intercollegiate athletes (soccer and volleyball) and they found that H:Q ratio was higher at 180 °/s (58.6 %) than at 120°/s (53.6 %) and at 60 °/s (49.8 %) angular velocities in female athletes (17). However, the ratios in their study were lower than the ratios in this study.…”

“…There was no descriptive data about the subjects' physical characteristics, hamstring and quadriceps peak torques so we could not hypothesize what cause the different outcomes between two studies. The similar finding of the other study reported an increase in the H:Q ratio from 61±14.3% at 60°/s to 62±14.7% at 90°/s in nondisabled, sedentary individuals (28).…”

Força muscular e índice de fadiga dos extensores e flexores do joelho de jogadores profissionais de futebol de acordo com o posicionamento em campo

“…Apesar de alguns estudos demonstrarem a ocorrência de assimetrias em atletas de futebol 2,9,11 , outros trabalhos não suportam esses achados 1,10,12 . Considerando as diferenças no gesto esportivo determinadas pelas diversas funções exercidas pelos jogadores, é possível que a presença de assimetria nesses atletas esteja relacionada ao posicionamento em campo.…”

Influência da fadiga unilateral de membro inferior sobre o salto vertical bilateral

“…However, it seems that fatigue of only one of the limbs alters this common command and dissociating the command for both limbs (1) . In practical terms, training, as well as the familiarization to tasks, may reduce the bilateral strength deficit minimizing the asymmetry, especially at fatiguing conditions, in which the control dissociation may modify the overload between limbs, since tasks which present asymmetry between limbs are more prone to injuries during physical performance (30)(31)(32)(33)(34)(35)(36) .…”