Interexaminer, Intraexaminer, and Test–Retest Reliability of Clinical Knee Joint-Position-Sense Measurements Using an Image-Capture Technique

Context: Knee joint position sense (JPS) plays a critical role in controlled and stable joint movement. Poor ability to sense position of the knee can therefore increase risk of injury. There is no agreed consensus on JPS measurement techniques and a lack of reliability statistics on methods. Objective: To identify the most reliable knee JPS measurement technique using image capture. Design: Inter-examiner, intra-examiner and test-retest reliability of knee JPS measurements. Setting: Biomechanics laboratory. Participants: Ten asymptomatic participants. Interventions: None. Main Outcome Measures: relative and absolute error scores of knee JPS in three conditions (sitting, prone, active) through three ranges of movement (10-30°, 30-60°, 60-90°), into two directions (flexion and extension) using both legs (dominant and non-dominant) collected during 15 trials and repeated seven days after the first data collection. Results: Statistical analysis by intraclass correlations revealed excellent inter-examiner reliability between researchers (0.98) and intra-examiner reliability within one researcher (0.96). Test-retest reliability was highest in the sitting condition from a starting angle of 0°, target angle through 60°-90°of flexion, using the dominant leg and AES variables (ICC = 0.92). However, it was noted smallest detectable differences (SDDs) were a high percentage of mean values for all measures. Conclusions: The most reliable JPS measurement for asymptomatic participants has been identified.Practitioners should use this protocol when collecting JPS data during pre-screening sessions. However, generalizability of findings to a class/group of clients exhibiting knee pathologies should be done with caution.