Lower limb joint burden during walking in adolescent idiopathic scoliosis: investigation of mechanical work during walking

BACKGROUND CONTEXT: Adolescent idiopathic scoliosis (AIS) is the most prevalent spinal deformity in adolescents. However, pathophysiology and long-term complications remain unclear. Characteristics of the mechanical work in AIS gait have not been well-studied. PURPOSE: This study aimed to elucidate the characteristics of mechanical work in AIS gait. STUDY DESIGN: Observational comparison study. PATIENT SAMPLE: Participants were composed of two groups: scoliosis group with 68 participants and a control group with 17 participants. OUTCOME MEASURES: Spinal deformity and coronal spinal balance in the scoliosis group were assessed with Cobb angle, coronal balance, and apical vertebra translation. Three-dimensional motion analysis during walking was conducted to calculate lower limb joint works and external work on the whole body's center of mass. METHODS: Lower limb joint work (JW) and external work on the whole body center of mass (CoM) were compared between the 2 groups with an independent t-test. Inter-limb and intra-limb comparisons of mechanical work were conducted with a paired t-test. The relationships between mechanical work and frontal trunk deformity were investigated in the scoliosis group. RESULTS: Walking speed and external work on whole body CoM did not differ between the two groups. Compared to the control group, the scoliosis group showed significantly larger JW on the convex and concave sides. CONCLUSION: The scoliosis group showed increased lower limb joint burden and limited trunk function for mechanical work during walking. Investigation of mechanical work during walking provides insight into the biomechanical characteristics of AIS. Therefore, future studies should be conducted to verify mechanical work characteristics which have relevance to the progression of spinal deformity and the development of lower limb complications in AIS.