Physical fitness and pulmonary function in adolescents with idiopathic scoliosis: a comparative study with healthy peers.

BACKGROUND: This study examined whether adolescents with adolescent idiopathic scoliosis (AIS) show functional limitations beyond musculoskeletal alignment by comparing physical fitness and pulmonary function with healthy peers. METHODS: In this cross-sectional study, adolescents aged 10-18 years with mild to moderate AIS were matched by age and sex to controls. A total of 48 individuals with AIS and 32 healthy peers were included. Physical fitness was assessed using selected Eurofit tests. Respiratory function was evaluated with spirometric parameters. Due to non-normal distributions, rank-based ANCOVA was applied with sex as a covariate. RESULTS: VO₂max, estimated from the shuttle run, was significantly lower in the AIS group (p<0.01, η²=0.420), indicating reduced cardiorespiratory fitness. Stage scores were also lower (p<0.01, η²=0.192), supporting impaired aerobic capacity. Flexibility was greater in AIS participants on the sit-and-reach test (p=0.023, η²=0.065), possibly reflecting compensatory adaptations or joint hypermobility. Shuttle run performance (10×5 m) was poorer in AIS (p=0.005, η²=0.096). Handgrip strength (p=0.002, η²=0.117) and broad jump performance (p=0.004, η²=0.104) were also significantly lower in the AIS group after adjusting for sex, whereas no significant differences were observed in spirometric parameters or balance. Sex influenced strength and endurance but not VO₂max, suggesting reduced aerobic capacity is specifically linked to AIS. CONCLUSIONS: Adolescents with AIS show impaired aerobic capacity and reduced muscle strength, while flexibility is preserved. Balance and pulmonary function remain unaffected in mild to moderate cases, underscoring the need for multidimensional fitness assessments and further research on scoliosis severity and connective tissue factors.