Test-retest reliability of knee kinematics measurement during gait with 3D motion analysis system

Abstract

Restoration of gait symmetry following anterior cruciate ligament reconstruction (ACLR) is crucial to minimize the risk of joint degeneration. To achieve this, it is essential that the chosen measurement method can accurately assess knee kinematics and detect the changes in multi- planes of motion. However to date, limited study is available on repeatability of the multi- planes knee angle measurements particularly among male patients post ACLR. The purpose of this study was to assess the test-retest reliability of knee kinematic measurements using three-dimensional (3D) motion analysis system during gait in post ACLR patients. Eight patients with mean (SD) age 28.89 (4.0) years, 5.82(4.07) months post ACLR were recruited from a tertiary hospital of Kuala Lumpur. All patients undergone two sessions of knee joint angles measurement during gait at four hours interval, for the injured and the non-injured knees. Angles in the sagittal, frontal and transverse planes during initial contact phase of gait that derived from the two measurement sessions were compared. The results showed high test-retest reliability of the measurement in sagittal and transverse planes; the intraclass correlation coefficient (ICC) was 0.97(95% CI: 0.84-0.99) and 0.96 (95% CI: 0.83-0.99) respectively, and moderate test-retest reliability for the measurements in frontal planes, with ICC 0.44 (95% CI: -0.32-0.86). The study findings suggest that multi-planes knee angle measurements during initial contact phase of gait could reliably be measured using a 3D motion analysis system. Further research may focus on knee kinematics measurements at other phases of gait.