Validity and Reliability of Whole-Body Anterior and Posterior Chain Muscles Test (WBAPT) in People with Knee Osteoarthritis (OA) and Knee Injuries: A Preliminary Study

Abstract

Background and Aim Knee OA (KOA) could lead to physical disabilities. People with knee injuries were at high risk of developing KOA. There are quite a number of KOA outcome measures but most of them are self-administered questionnaires. Only few clinician-reported outcome measures are available and rarely assess the whole-body muscle strength and endurance. WBAPT was developed and this study aimed to test validity and reliability of WBAPT. Methods Thirteen participants with KOA and knee injury history were included. Repetitions per minute of standing hip flexion-extension with arm raised (left and right), standing with hip and shoulder abduction (left and right), superman, squat with trunk rotation, hinge with calves raised were assessed in WBAPT. A retest was performed in one week time. Results The Cronbach’s α of WBAPT was 0.914. Internal Cronbach’s coefficient α within WBAPT subscales which were standing hip flexion-extension with arm raised (left and right), standing with hip and shoulder abduction (left and right), superman, squat with trunk rotation and hinge with calves raised were 0.897, 0.897, 0.901, 0.900, 0.904, 0.921 and 0.897 for test 1 and 0.909, 0.905, 0.908, 0.904, 0.916, 0.925 and 0.912 for test 2 consecutively. Test–retest reliability was assessed by paired samples t-test and there was no significant difference. The Pearson's correlation values between test 1 and test 2 showed moderate to high degree of correlation in all subscales except superman exercise which was with low degree of correlation. Conclusion WBAPT showed a good internal consistency. With increasing sample size, WBAPT test-retest reliability can be improved.