This study was done to determine the imbalance of weakness between knee flexor and extensor by isokinetic test in degenerative joint disease (DJD), the efficacy of quadriceps isometric strengthening and to know whether the result of isokinetic test correlated with radiologic grade, visual analogue scale (VAS), duration of pain or body mass index.

51 patients with degenerative joint disease of knee who met the clinical criteria of American Rheumatology Association and the Kellgren's radiologic grade II or more, were evaluated with Cybex II+ isokinetic dynamometer. VAS, duration of pain and body mass index of them were measured, too.

In isokinetic test result, the torque values were significantly lower in DJD patients than normal and the hamstring to quadriceps ratio (H/Q ratio) was significantly higher in DJD patients than normal; 62.3% vs. 51.6% in 6th decade. 5 of 7th decade and 4 of 8th decade showed no measurable torque value at angular velocity 180 degree/sec. Radiologic grade, VAS and duration of pain showed no significant correlation with the result of isokinetic testing.

In conclusion, we think that, in DJD patients strengthening of knee musculature, especially knee extensor should be emphasized. In 7th decade or more, it would be better to measure the isokinetic torque value at low angular velocity of measure the isometric torque for measuring the strength of knee musculature.