Effects of hypermobility on physical assessment parameters in adolescents with idiopathic scoliosis: a case-control study

OBJECTIVES: The aim of this study was to investigate the effects of hypermobility on scoliosis degree, trunk rotation, lower extremity length difference, pes planus status, static and dynamic balance, and fall risk in individuals diagnosed with adolescent idiopathic scoliosis (AIS). METHODS: This case-control study included 33 individuals with AIS (18 hypermobile, 15 non-hypermobile), aged 10-18 years, with Cobb angles ranging from 10° to 45°. Hypermobility was assessed using the Beighton Score, and those scoring 5 or higher were considered the hypermobile group. The degree of scoliosis was measured using the Cobb angle method, and trunk rotation was measured using a scoliometer. Lower extremity length discrepancy was assessed using a tape measure, and pes planus was assessed using the Navicular Drop Test. Static balance was determined using the Single-Leg Balance Test (eyes open/closed), dynamic balance using the Functional Reach Test (FUT), and fall risk was measured using the Morse Fall Scale. Data were analyzed using SPSS, and intergroup comparisons and correlations were evaluated. RESULTS: Lumbar trunk rotation was significantly lower in the hypermobile group (p=0.02). No group differences were observed in other physical parameters. Positive correlations were found between the Cobb angle and upper thoracic and lumbar trunk rotation; a significant positive correlation was also found between the Cobb angle and pes planus status. Hypermobility was linked to gender, and better dynamic balance was associated with a lower risk of falling. CONCLUSIONS: In individuals with AIS, hypermobility was determined to affect trunk rotation angle, particularly in the lumbar region, and to be associated with pes planus. Routine evaluation of hypermobility and pes planus is recommended, alongside exercises targeting dynamic balance to help reduce fall risk.