Isokinetic assessment of the flexor-extensor balance of the knee in athletes with total rupture of the anterior cruciate ligament

Abstract

The purpose of this study was to assess the flexor-extensor group of muscles of the knee in young athletes diagnosed with a total rupture of the anterior cruciate ligament (ACL). Eighteen knees of 18 athletes (14 men and 4 women) with an average age of 21.6 years (range 16-32 years) were assessed with a Cybex 6000 model isokinetic apparatus. The average internal between occurrence of the injury and assessment was 10.2 months (range 2-48 months). There was an associated meniscal injury in eight of the knees. Athletes with any other kind of associated injury, limitation, or blockage of the movement of the joint, significant pain during the exam, or interval between injury and exam of less than two months were excluded from the study. The parameters studied were the peak torque-velocity and flexor-extensor relationships at the constant angular velocities of 60 degrees/sec and 240 degrees/sec. Previous warming-up was done by means of an ergometric bicycle and adaptation with 3 submaximal repetitions. The contra-lateral side, which presented no injury, was used as control. Peak torque (PT) at the constant velocity of 60 degrees/sec was greater than that at 240 degrees/sec for knees with and without injuries. However, there was no significant difference between the injured and uninjured sides at 60 degrees/sec or at 240 degrees/sec. The average value for the flexor-extensor relationship at 60 degrees/sec on the injured was 60% ((6), compared to 57% ((10) on the contra-lateral side. At 240 degrees/sec, the average value was 75% ((10) on the injured side, and 65% ((12) on the contra-lateral side. In conclusion, despite the complete rupture of the ACL of one knee, the average values for the flexor-extensor relationship were similar on the injured and uninjured sides at the velocity of 60 degrees/sec. As the velocity increased, an increase in the values for the flexor-extensor relationship of the knee also occurred, indicating a tendency of the performance of the flexor muscle group to approach that of the extensor muscle group, and this tendency was more pronounced on the side of the injury.

Existe diferença nos testes de força da dinamometria isocinética entre jogadores profissionais de futebol de campo e de futebol de salão?

“…The left knee presented higher peak torque, on average, for both muscles. among Brazilian sports clubs as a tool for injury prevention, implemented during the preseason period (8,9) . The indications for the examination relate to studying the proportions of agonist and antagonist muscle balance and the difference in agonist muscle groups between one side and the other.…”

Avaliação isocinética no joelho do atleta

“…Mostra-se útil nos indivíduos que tiveram lesão do aparelho locomotor. Por exemplo, no joelho a relação entre o pico de torque dos flexores/extensores é por volta de 60% 5 , ou seja, o valor absoluto do pico de torque dos flexores (numerador) dividido pelo dos extensores (denominador) resulta num valor em percentagem igual a 60. Portanto, a diferença entre os extensores (mais fortes) e os flexores (mais fracos) é de 40%.…”

“…Em-bora o termo isocinético tenha sido já definido em 1967 1 , seu uso tornou-se mais expressivo nas últimas duas décadas. No nosso meio, a experiência tem sido crescente nos últimos 10 anos [2][3][4][5] .…”

Avaliação isocinética no joelho do atleta

“…Um estudo realizado com atletas com ruptura total de LCA num dos joelhos mostrou valores do equilíbrio flexor/ extensor semelhantes na velocidade de 60º/seg entre os lados acometido (60%) e não acometido (57%), apesar da ruptura completa do LCA 5 . O mesmo não ocorreu na velocidade rápida de 240°/seg, que no lado acometido mostrou relação de 75% e no lado não acometido 65%, havendo diferença estatisticamente significante.…”

“…Embora o termo isocinético tenha sido já definido em 1967 1 , seu uso tornou-se mais expressivo nas últimas duas déca-das. No nosso meio, a experiência tem sido crescente nos últimos 10 anos [2][3][4][5] .…”