Inter- and intrarater reliability of two proprioception tests using clinical applicable measurement tools in subjects with and without knee osteoarthritis

Background: The therapeutic value of proprioceptive-based exercises in knee osteoarthritis (KOA) management warrants investigation of proprioceptive testing methods easily accessible in clinical practice. Objective: To estimate inter-and intrarater reliability of the knee joint position sense (KJPS) test and knee force sense (KFS) test in subjects with and without KOA. Design: Cross-sectional test-retest design. Method: Two blinded raters performed independently repeated measures of the KJPS and KFS test, using an analogue inclinometer and handheld dynamometer, respectively, in eight KOA patients (12 symptomatic knees) and 26 healthy controls (52 asymptomatic knees). Intraclass correlation coefficients (ICCs; model 2,1), standard error of measurement (SEM) and minimal detectable change with 95% confidence bounds (MDC95) were calculated. Results: For KJPS, results showed good to excellent test-retest agreement (ICCs 0.70-0.95 in KOA patients; ICCs 0.65-0.85 in healthy controls). A 2 degrees measurement error (SEM 1 degrees) was reported when measuring KJPS in multiple test positions and calculating mean repositioning error. Testing KOA patients pre and post therapy a repositioning error larger than 4 degrees (MDC95) is needed to consider true change. Measuring KFS using handheld dynamometry showed poor to fair interrater and poor to excellent intrarater reliability in subjects with and without KOA. Conclusions: Measuring KJPS in multiple test positions using an analogue inclinometer and calculating mean repositioning error is reliable and can be used in clinical practice. We do not recommend the use of the KFS test to clinicians. Further research is required to establish diagnostic accuracy and validity of our KJPS test in larger knee pain populations