ABSTRACT
BACKGROUND: Scoliosis may have an effect on gait parameters, the kinematics of the lower limbs and the spine, and mechanical work with specific gait speed. Imposed gait speed may influence these effects. Following spinal fusion in the case of idiopathic scoliosis, patients fear subsequent and considerable back stiffness and kinetic consequences. The aim of this retrospective study was to evaluate the upper body range of motion and mechanical work before and after spinal fusion in of free gait speed conditions. METHODS: Twenty-two patients with idiopathic scoliosis and twenty-two asymptomatic controls were included. Patients were analyzed before and one year after spinal fusion. Based on full body modeling and motion capture, we measured gait speed, cadence, stride length, the mobility of the upper and lower spinal segments (in each plane), and mechanical work (with and without dimensionless scaling strategy). FINDINGS: Patients walked significantly slower than controls. The same speed was noticed before and after fusion. Only the lower back kinematics in the frontal plane was reduced before fusion. Spinal fusion further reduced the mobility of the pelvis segment in the sagittal plane in comparison to controls. Scaling external work was associated with higher values for patients. INTERPRETATION: Spinal fusion improves pelvic and thorax-pelvis mobility (during the stance phase) in the frontal plane. The impact of scoliosis on the upper body range of motion was limited on the thorax-pelvis, corresponding to a stiffening effect. With such restrictions, an increase in normalized external work was observed for similar normalized internal work.
