Abstract
Plantar flexors (PF) of sixty-two patients were tested on the Cybex II Dynamometer about three weeks after anterior cruciate ligament (ACL) surgery. Compared to the non-injured extremity, the deficit is in the range of 30–40%. The authors emphasize the important role of the PF in the stability of the knee and thus the need to reinforce them in a comprehensive program of rehabilitation after ACL surgery.