Comparison of two periods of Schroth exercises for improving postural stability indices and Cobb angle in adolescent idiopathic scoliosis

BACKGROUND: Adolescents with idiopathic scoliosis present postural instability when compared with healthy subjects. Although Schroth exercises therapy (SET) is broadly utilized, its effect on postural stability is still not clear. OBJECTIVES: To compare the two treatment periods of the SET for improving the postural stability indices and Cobb angle, and to examine the correlation between the Cobb angle and stability indices in adolescent idiopathic scoliosis (AIS). METHODS: Twenty girls aged 10-16 years with AIS (study group) and 20 age-matched girls without AIS (control group) were examined. The Biodex Balance System was used to evaluate the overall stability index (OSI), anteroposterior index (APSI), and mediolateral stability index (MLSI) in the study group before SET and one and three months after the therapy. A plain X-ray was used to measure the Cobb angle before and three months after SET. Stability indices and Cobb angle were measured only once for the control group. RESULTS: One-way repeated-measures ANOVA revealed that the three-month duration of SET was the most effective for improving OSI, APSI, and MLSI (p< 0.001). The significant proximities of OSI, APSI, and MLSI to the normal values post three months of SET were 29.65%, 24.07, and 20% respectively. The MLSI was robust and correlated with the Cobb angle (r= 0.85) three months post intervention. CONCLUSION: Stability indices and Cobb angles were highly improved after three months of SET compared to one month among AIS patients. The MLSI is the most substantial index correlated with the Cobb angle.