The relationships of functional capacity, pain, and isometric and isokinetic torque in osteoarthrosis of the knee.

Thirty-nine patients suffering from osteoarthrosis of the knee were repeatedly measured. The relationship was studied for two groups of variables. The first group consisted of subjective assessments of functional capacity and pain and a walking test. The second group consisted of isometric knee extension torque and isokinetic knee flexion and extension torque at 30 degrees/sec, 60 degrees/sec, 120 degrees/sec and 180 degrees/sec. High correlations between each of the static and dynamic torque values were found. Multiple regression analysis showed that isometric and isokinetic torque measures are unsatisfactory predictors of functional capacity, since only 23-35% of the variation of functional capacity, pain and walking test variables was explained by the variation of torque variables. Dynamic torque measurements had very little advantage over static torque tests. It is concluded that outcome measures in studies of osteoarthrosis should be problem-oriented and include direct assessments of functional capacity, pain and walking ability.