Altered Lower-Limb Dynamics in Stop-Jump Activity of Adolescents With Major Thoracic Scoliosis

Adolescent idiopathic scoliosis (AIS) may alter lower-limb biomechanics and neuromuscular control in high-demanding activities, like stop-jump. Understanding these alterations is crucial for effective rehabilitation. This study aimed to compare lower-limb biomechanics during stop-jump between AIS and healthy individuals. Twelve physically active adolescents with major thoracic AIS and 12 matched controls were recruited. A motion analysis system and 2 force plates recorded kinematic data and ground reaction forces, based on which the angles, velocities, moments, and power of the lower-limb joints were calculated and compared between the 2 groups. Results indicated that the AIS group exhibited greater hip power (P = .04) and extension velocity (P = .03) in takeoff and reduced hip abduction angle (P = .005) and velocity (P = .004) with increased hip abduction moment (P = .01) in landing. They also demonstrated altered knee rotation (P = .02) and a shorter time to stability (P < .05) after landing. The spinal deformity in AIS leads to altered hip and knee biomechanics during stop-jump tasks. The scoliosis group exhibited increased hip power and altered joint kinematics during takeoff, alongside a stiffer landing pattern. These changes highlight a disrupted kinetic chain, underscoring the need for rehabilitation that addresses both spinal and lower-limb mechanics.