Trunk Kinematic Analysis of Ascent and Descent Stairs in College Students with Idiopathic Scoliosis: A Case-Control Study.

BACKGROUND CONTEXT: Traditional 3D motion analysis typically considers the spine as a rigid entity. Nevertheless, previous single-joint models have proven inadequate in evaluating the movement across different spinal segments in patients with idiopathic scoliosis (IS). Scoliosis significantly impairs movement functions, especially during activities such as ascending and descending stairs. There is a lack of research on the patterns of stair movement specifically for patients with IS.

PURPOSE: This study aims to investigate the trunk kinematics in college students with IS during stair ascent and descent tasks. A total of 56 participants, 28 with IS and 28 healthy controls, were recruited for this case-control study. The trunk movements were analyzed using a motion analysis system that incorporated a multi-segment spine model. Understanding the multi-segment spine kinematics during stair tasks can contribute to the development of effective rehabilitation programs for individuals with IS.

STUDY DESIGN: Case-control study SAMPLE SIZE: 28 IS and 28 controls OUTCOME MEASURES: Cobb angle, spinal curvature, spinal active range of motion (ROM), Kinematics METHODS: The Qualisys system (Gothenburg, Sweden) was utilized in this study with a sampling frequency of 150Hz. It recorded the kinematics in the thoracic, lumbar, thoracic cage, and pelvis during ascending and descending stairs for both the 28 IS individuals and the 28 control participants. Additionally, clinical parameters such as the Cobb angle, curvature of the spine, spinal range of motion (ROM), and other relevant factors were concurrently assessed among the subjects. Project supported by the National Natural Science Foundation of China (Grant No. 82205306). The authors declare no conflict of interest in preparing this article.

RESULTS: The findings of this study revealed that IS individuals exhibited reduced kyphotic curvature in the sagittal plane (P<0.05) when compared to the control group. In contrast, these IS patients displayed greater coronal curvature (Cobb angle) in the frontal plane and a more substantial difference in thoracic side bending range of motion in comparison to the control group (P<0.05). Moreover, during the ascending stair activity, IS patients showed reduced thoracic cage flexion-extension range of motion (P<0.05), while displaying increased lumbar rotation range of motion and anterior-posterior pelvic tilt range of motion (P<0.05) in contrast to the control group. Notably, the kinematic analysis during the descent of stairs indicated that IS patients exhibited larger range of motion in thoracic flexion-extension, thoracic side bending, thoracic cage side bending, thoracic rotation, and thoracic cage rotation when compared to the control group (P<0.05).

CONCLUSIONS: The results showed significant differences in trunk kinematics between the two groups during both stair ascent and descent tasks. The utilization of the "multi-segment spine model" facilitates the acquisition of motion information across multiple segments of the spine in patients diagnosed with IS, effectively enhancing the assessment outcomes derived from imaging information. The three-dimensional structural deformity in the trunk affects both static and dynamic activity patterns. In different activity states, IS patients demonstrate stiff movements in certain segments while experiencing compensatory instability in others. In the future, clinical rehabilitation programs for IS should prioritize stair-related activity training.