A Weight Loading Device as a Method for Assessment of Unilateral Knee Pain

ABSTRACT

OBJECTIVE: To identify the effectiveness of a weight loading device as a method for assessment of unilateral knee pain. METHOD: Twenty-five patients with unilateral knee pain and 25 pain-free controls participated in this study. Patients with a score of 2 or more on modified Kellgren-Lawrence scale based on the radiologic findings were diagnosed as degenerative arthritis. We constructed a device of segmental foot plates with strain gauge weight sensors to measure the weight load of each leg during self-selected walking speed. Using this device, we obtained the ratio of symptomatic side to asymptomatic side of weight load (RATIO) for each patient. The degree of pain according to visual analogue scale (VAS), abnormalities in radiologic findings, and weight load ratio were compared with each other. RESULTS: The RATIO was 1.00+/-0.03 in the control group, and 0.92+/-0.08 in the patient group (p<0.05). In the patient group, there was a significant correlation between RATIO and the VAS score (r=-0.44, p=0.03). In the patient group with degenerative arthritis, the RATIO (p=0.75) and VAS (p=0.94) were not different from those in patient group without degenerative arthritis. CONCLUSION: The foot plate weight loading device may be an effective tool for convenient measurements of knee pain.