Identifying functional movement deficits in mild to moderate adolescent idiopathic scoliosis: a cross-sectional study

Currently, research on adolescent idiopathic scoliosis (AIS) focuses more on corrective treatment and prevention, and few studies have been conducted on movement deficits within this population. Study utilized a functional movement screening (FMS) method to test and evaluate movement characteristics of patients with AIS.

Functional movement performance was evaluated in adolescents with mild-to-moderate AIS using the FMS protocol. Kendall's Tau correlation analysis was employed to examine the relationship between FMS scores and Cobb angle magnitude. Based on the number of curves and directions of Cobb angles, three main classifications of scoliosis were found within participants: thoracolumbar double-curve, thoracic single-curve, and lumbar single-curve.

The mean composite FMS score for all the participants (n = 32) was 11.78 ± 1.5, while double-curve group scored slightly lower (11.8 ± 1.0) than single-curve group, although the difference was not significant (P > 0.05). Among individual FMS movements, Trunk Stability Push-Up (TSP) demonstrated the lowest score (0.88 ± 0.79). In sex-based comparison, males performed significantly better in left Hurdle Step (HS) and TSP (P < 0.05), whereas females scored significantly higher in right Shoulder Mobility (SM) and bilateral Active Straight Leg Raise (ASLR) (P < 0.05). Importantly, Kendall's Tau correlation analysis revealed no significant correlation between Cobb angle magnitude and total FMS scores (r = 0.136, P > 0.05) in the overall cohort. The only exception was Rotary Stability (RS), demonstrating a weak but significant positive correlation with Cobb angle (r = 0.336, P < 0.05).

Adolescents with mild to moderate AIS exhibit composite FMS scores consistently below the clinical reference threshold of 14, indicating generalized functional movement deficits. Importantly, the generalized deficits exist independently of radiographic severity of the AIS, indicating the necessity for functional assessments in addition to radiographic analysis. Meanwhile, these limitations were particularly noticeable in trunk stability, suggesting a need for targeted motor control training.