Analysis of coordination between thoracic and pelvic kinematic movements during gait in adolescents with idiopathic scoliosis

Purpose: In this research, we investigated the coordination pattern and consistency of coordination between the thorax and pelvis during gait in patients with idiopathic scoliosis. Methods: Across the study, 69 adolescent girls (controls: 30, patients: 39) participated. All participants were asked to walk 10 m barefoot at a self-selected speed. The walking speed, stride length, and range of motion of the pelvic and thoracic angles were collected using a three-dimensional optical motion analysis system, and the thorax–pelvis coordination was quantified using a vector coding technique. The frequency of four different patterns of coordination (in-phase, anti-phase, pelvis only, and thorax only) and the consistency of coordination including direction and magnitude during the gait cycle of the two groups were investigated. Independent-sample t tests were performed to examine differences between the two groups with regard to coordination patterns and consistency. Results: The patients with idiopathic scoliosis showed significantly higher in-phase and relatively lower anti-phase in the transverse plane compared to controls. Additionally, the pelvis only in the transverse, frontal, and sagittal planes was significantly lower in patients. The consistency of coordination in patients was significantly lower than in controls in direction and magnitude on the transverse and frontal planes. Conclusion: From viewpoint of the thorax–pelvis coordination, patients with IS had less gait stability in the trunk than controls.