Repeatability of position sense measurements in persons with osteoarthritis of the knee: a pilot study

Abstract

Several reports have described a position sense deficit in persons with osteoarthritis of the knee. For purposes of future comparison, this study determined the agreement between serial measurements of knee position sense conducted over a 10-day period for eight persons of mean age 67.87 ± 7.36 years with stable knee-joint disease. The knee angles used to determine position sense were recorded in the seated position using a potentiometer. The outcome measure was the mean absolute error between five set angles and their matching angles. The intra-class correlation coefficients (ICCS) used to assess reliability of the mean absolute error measurements within and between sessions ranged from 0.57 to 0.52 with an average standard error of measurement of 1.18 degrees. It is concluded that while fairly reliable, clinicians should interpret changes in knee position sense of less than 2.31 degrees carefully in these patients before concluding that a true improvement or deterioration in their knee positioning accuracy has occurred.