Contraction patterns during isokinetic eccentric and concentric contractions after anterior cruciate ligament injury

Muscular fatigue was investigated in m. rectus femoris, m. vastus lateralis and medialis of 15 patients after an anterior cruciate ligament injury. Using a Lido active (isokinetic) dynamometer, combined eccentric and concentric contractions were carried out at intermediate contractile velocity speeds (150 degrees, 240 degrees/s). In addition, concentric contractions were also performed at fast angular velocities (300 degrees, 400 degrees/s). The results indicated that fatigue was significantly greater for the intermediate speeds. Given one angular velocity, the average eccentric force decline was more pronounced than the concentric one. At all velocities the relative decrease of peak torque (PT) was smaller than for contractional work (CW).