College of Public Health and Human Sciences

STUDY DESIGN: Case-controlled design; biomechanics laboratory setting.

OBJECTIVE: To compare the spine and lower extremity kinematics displayed during high-effort running between individuals with spinal fusion surgery for adolescent idiopathic scoliosis (SF-AIS) and healthy controls (CON).

SUMMARY OF BACKGROUND DATA: Individuals with SF-AIS often return to exercise and sports that include running. However, how these individuals produce the spinal rotations needed during high-effort running and thus compensate for the loss of spinal flexibility is not known.

METHODS: Ten SF-AIS (posterior-approach spinal fusion; postoperative time: 2.0 ± 0.6 years; physically active) and 10 CON individuals, pair-matched for gender, age, mass, height, and level of physical activity participated. SF-AIS individuals ran on a treadmill at a self-selected submaximal speed perceived as "hard" (15/20 on Borg perceived-effort scale), and CON ran at the SF-AIS pair-matched speed. 3D motion capture system was used to generate trunk and pelvis segmental angles (trunk segments = upper trunk [C7-T8], middle trunk [T9-T12], lower trunk [L1-L5]), relative angles (relative angles between the two consecutive trunk segments), and lower extremity joint angles. The group differences between the SF-AIS and CON were assessed using one-way analysis of covariance (with running speed as the covariate) for trunk, lower extremity, and step kinematics.

RESULTS: SF-AIS participants exhibited a significantly greater (6.1° greater) lower trunk and (6.3° greater) pelvis segmental axial rotation compared with CON during running. In addition, SF-AIS participants displayed a 9.2° less ankle plantarflexion during the support phase. There were no significant differences detected for step kinematics.

CONCLUSION: Possibly because of relearned compensatory mechanism, individuals with SF-AIS displayed similar patterns of spine, lower extremity, and step kinematics as healthy controls during high-effort running with some exceptions.

LEVEL OF EVIDENCE: Level III.