This study was designed to determine whether an 8-week isokinetic muscle-strength-training program improved the functional health status of patients with osteoarthritis of the knee joint. Twenty volunteers with osteoarthritis of the knee joint were randomly assigned to either an experimental (n=10) or control (n=10) group. The experimental group completed six sets of five maximal contractions three times per week for 8 weeks on a Cybex II dynamometer at 90 degrees per second. Both groups were pre- and posttest for extension and flexion strength of the right and left legs, the 50-foot walk time, range of motion at the knee joint, the Osteoarthritis Screening Index (OASI), and the Arthritis Impact Measurement Scale (AIMS). There was a significant decrease in pain and stiffness, and a significant increase in mobility. There was also a significant decline in arthritis activity in the experimental group as measured by the OASI and AIMS. The experimental group significantly increased in all strength measures, while the control group increased in only right leg flexion and left leg extension across the training period.