English

Abstract

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.