Thirty-three patients with autogenous hamstring ACL reconstruction were randomly divided into study (n=16, mean age; 33.87±8.19) and control (n=17, mean age; 32.64±8.21) groups and followed the same ACL rehabilitation program. Additionally, the study group followed a progressive eccentric and concentric training for 12 weeks on the Monitorized Functional Squat System (MFSS) beginning 3 weeks after surgery. The groups were compared according to the isokinetic strength of the knee extensors and flexors, functional performance (the vertical jump test, a single hop for distance test) and the Lysholm knee scale, the Anterior Cruciate Ligament-Quality of Life Questionnaire (ACL-QOL), before and 16 weeks after the surgery.