Background: In North America, care recommendations for adolescents with small idiopathic scoliosis (AIS) curves include observation or bracing. Schroth scoliosis-specific exercises have demonstrated promising results on various outcomes in uncontrolled studies. This randomized controlled trial (RCT) aimed to determine the effect of Schroth exercises combined with the standard of care on quality-of-life (QOL) outcomes and back muscle endurance (BME) compared to standard of care alone in patients with AIS.
Material and methods: Fifty patients with AIS, aged 10-18 years, with curves 10-45 °, recruited from a scoliosis clinic were randomized to receive standard of care or supervised Schroth exercises plus standard of care for 6 months. Schroth exercises were taught over five sessions in the first two weeks. A daily home program was adjusted during weekly supervised sessions. The assessor and the statistician were blinded. Outcomes included the Biering-Sorensen (BME) test, Scoliosis Research Society (SRS-22r) and Spinal Appearance Questionnaires (SAQ) scores. Intention-to-treat (ITT) and per protocol (PP) linear mixed effects models were analyzed. Because ITT and PP analyses produced similar results, only ITT is reported.
Results: After 3 months, BME in the Schroth group improved by 32.3 s, and in the control by 4.8 s. This 27.5 s difference in change between groups was statically significant (95 % CI 1.1 to 53.8 s, p = 0.04). From 3 to 6 months, the self-image improved in the Schroth group by 0.13 and deteriorated in the control by 0.17 (0.3, 95 % CI 0.01 to 0.59, p = 0.049). A difference between groups for the change in the SRS-22r pain score transformed to its power of four was observed from 3 to 6 months (85.3, 95 % CI 8.1 to 162.5, p = 0.03), where (SRS-22 pain score)(4) increased by 65.3 in the Schroth and decreased by 20.0 in the control group. Covariates: age, self-efficacy, brace-wear, Schroth classification, and height had significant main effects on some outcomes. Baseline ceiling effects were high: SRS-22r (pain = 18.4 %, function = 28.6 %), and SAQ (prominence = 26.5 %, waist = 29.2 %, chest = 46.9 %, trunk shift = 12.2 % and shoulders = 18.4 %).
Conclusions: Supervised Schroth exercises provided added benefit to the standard of care by improving SRS-22r pain, self-image scores and BME. Given the high prevalence of ceiling effects on SRS-22r and SAQ questionnaires' domains, we hypothesize that in the AIS population receiving conservative treatments, different QOL questionnaires with adequate responsiveness are needed.
Trial registration: Schroth Exercise Trial for Scoliosis NCT01610908.
Keywords: Adolescent idiopathic scoliosis; Muscle endurance; Quality of life; Randomized controlled trial; Schroth exercises.