Development of supine and standing knee joint position sense tests

Objectives: We aimed to assess the test-retest reliability of a supine and standing knee joint position sense (JPS) test, respectively, and whether they discriminate knees with anterior cruciate ligament (ACL) injury from asymptomatic knees. Design: Repeated measures and cross-sectional. Setting: Research laboratory. Participants: For test-retest reliability, 24 persons with asymptomatic knees. For discriminative analysis: 1) ACLR -18 persons on average 23 months after unilateral ACL reconstruction, 2) CTRL - 23 less-active persons, and 3) ATHL - 21 activity level-matched athletes. Main outcome measures: Absolute error (AE) and variable error (VE). Results: Test-retest reliability was generally highest for AE of the standing test (ICC 0.64-0.91). Errors were less for the standing compared to the supine test across groups. CTRL had greater knee JPS AE (P = 0.005) and VE (P = 0.040) than ACLR. ACLR knees showed greater VE compared to the contralateral non-injured knees for both tests (P = 0.032), albeit with a small effect size (eta(2)(p) = 0.244). Conclusions: Our standing test was more reliable and elicited lesser errors than our supine test. Less-active controls, rather than ACLR, produced significantly greater errors. Activity level may be a more predominant factor than ACLR for knee JPS similar to 2 years post-reconstruction. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).