Association of scoliosis with lower extremity alignments, muscle strengths, and foot characteristics and their alterations in adolescent idiopathic scoliosis

BACKGROUND: The association between changes occurring in the spine and lower body parts is not well understood in adolescent idiopathic scoliosis (AIS). OBJECTIVES: The first aim of the study was to investigate the association of scoliosis with lower extremity (LE) alignments, foot characteristics, and muscle strengths in adolescents. Secondly, comparisons of the data among AIS with single and double curves and control groups were determined. METHODS: Thirty-one participants were recruited and classified into 3 groups; AIS with a single curve (n= 7), AIS with double curves (n= 14), and controls (n= 10). Association of the presence of scoliosis with LE alignments (Q and TC angles), LE muscle strengths (hip, knee, and ankle), and foot characteristics (arch indexes) were examined using the point biserial correlation, and the data among three groups were compared using the ANOVA. RESULTS: Scoliosis was associated with Q angle, arch indexes, and all LE muscle strengths except for hip extensors and ankle plantar flexors strengths. Comparisons among the three groups showed significant increases in LE alignments and foot characteristics in AIS. Almost all LE muscle strengths decreased in AIS, especially for the single curve group. CONCLUSIONS: Apart from spinal deformity, the AIS has changed in LE alignments, muscle strengths, and foot characteristics. Therapists should consider these associations and alterations for designing proper management.