Head Control During Walking In Subjects With Adolescent Idiopathic Scoliosis

Gait analysis of patients with adolescent idiopathic scoliosis (AIS) has occasionally been written reported, but there are few studies on the control of head movement. It has been reported that the rate of malocclusion is high in patients with AIS, which also affects the control of head posture. PURPOSE: The purpose of this study was to investigate the head movement pattern during walking in patients with AIS. METHODS: Movement patterns of the pelvis, thorax, and head obtained from the optical three-dimensional motion analysis during walking were compared between patients with AIS (10 < Cobb angle [deg.] < 30, n = 8, age: 15.0 ± 5.65 yrs. [AIS]) and patients without AIS (n = 7, age: 19.9 ± 8.64 yrs. [C]). Two-way ANOVA was used for statistical analysis between group [AIS-C] and within subject [segment]. RESULTS: Range of pitch angles [mean ± SD, degrees] for each segment was 4.0 ± 1.28 [AIS] and 3.2 ± 0.77 [C] at the pelvis, 4.8 ± 1.58 [AIS] and 4.2 ± 0.92 [C] at the thorax, 7.8 ± 2.48 [AIS] and 5.0 ± 0.97 [C] at the head, respectively. Statistically significant interaction was observed, and the head moved more than the pelvis and thorax in AIS (F = 15.92, p < .01, ES f = 1.107), and more than C (F = 6.91, p < .05, ES f = 0.729). Range of yaw angles for each segment is 18.6 ± 4.98 [AIS] and 12.5 ± 3.68 [C] at the pelvis, 7.4 ± 1.74 [AIS] and 6.7 ± 1.81 [C] at the thorax, 5.3 ± 2.31 [AIS] and 3.7 ± 1.10 [C] at the head. Interaction was also observed in the yaw angle range (F = 4.91, p < .05, ES f = 0.615), and head movement in AIS was larger than C (F = 2.46, p > .05, ES f = 0.435). Range of roll angles for each segment was 10.7 ± 2.72 [AIS] and 11.0 ± 2.13 [C] at the pelvis, 4.2 ± 1.60 [AIS] and 3.6 ± 0.86 [C] at the thorax, 5.0 ± 2.35 [AIS] and 3.5 ± 1.31 [C] at the head. Difference was observed in the roll angle range between segments (pelvis > thorax = head), but no interaction and no difference between AIS and C. CONCLUSIONS: Head movement pattern during walking was large in AIS patients, and movement control was inadequate. Although vestibular deficits were observed in patients with scoliosis in previous studies, it is thought that the AIS subjects in this study also influenced the balance strategy. On the other hand, as most AIS patients have malocclusion, we would like to investigate whether cervical muscle hypertonicity is affected by malocclusion or the vestibular function declines.