Motion analysis in patients with postpartum sacroiliac joint dysfunction:A cross-sectional case-control study

BACKGROUND: Patients with sacroiliac joint dysfunction are limited in daily life activities such as gait, climbing stairs and rising from a chair. It is well known that individuals with chronic low back pain have impaired balance compared to healthy individuals. This cross-sectional case-control study aims to investigate spatiotemporal parameters, center of pressure and mass, pelvic angles and other joint angles in patients with sacroiliac joint dysfunction in comparison with healthy controls.METHODS: Motion analysis existed of three tasks: (1) normal gait, (2) single-leg-stance, and (3) sit-to-stance. Spatiotemporal parameters, center of pressure, pelvic angles and other joint angles were measured using a twelve-camera, three-dimensional motion capture system and ground reaction force platforms.FINDINGS: Thirty subjects were recruited for this study; ten patients, ten matched controls and ten healthy student controls. For gait, patients had a lower cadence, longer double support phase, shorter step length and slower walking speed than controls. For single-leg-stance, patients had a smaller hip angle of the risen leg than controls. Also, variability in center of pressure was larger in patients. For sit-to-stance, the total time to perform the task was almost doubled for patients compared to controls.INTERPRETATION: This study demonstrates that patients with sacroiliac joint dysfunction have an impaired gait, more balance problems during standing and standing up compared to healthy controls. This novel information assists to further comprehend the pathology and disease burden of sacroiliac joint dysfunction, in addition, it may allow us to evaluate the effect of current therapies.