Movement of the knee in osteoarthritis - The use of electrogoniometry to assess function

We used electrogoniometers to measure the range of movement (ROM) of the kn ee during various activities, comparing 50 patients with osteoarthritis of the knee (OA) with 20 healthy age- and sex-matched subjects. The minimum and maximum joint angles and the ranges of excursion of the pat ient and control groups were tested for significant differences, using an u nrelated Student's t-test with pooled variance. Knee flexion in patients wi th OA was significantly reduced during all activities (p < 0.05). but diffe rences in knee extension were not significant except when patients negotiat ed stairs. We believe that this reduction in ROM is caused by inhibition du e to pain when load-bearing. Static non-load-bearing measurements of the RO M poorly reflected the functional ROM, with a coefficient of determination (r(2)) Of 0.59 in the patient group and 0.60 in the control group. Electrogoniometry of the ROM of the knee provides a reliable, accurate and objective measurement of knee function.