Inspiratory Muscle Training Plus Schroth Exercise Versus Schroth Exercise Alone on Respiratory Function in Idiopathic Scoliosis
In brief
Added breathing training raised lung capacity to 79% vs 74% predicted
In a 12-week randomized trial of 68 adolescents with scoliosis, adding inspiratory muscle training to Schroth exercises improved lung function, breathing muscle strength and walking distance more than Schroth exercises alone. Spinal curve measurements did not differ between groups, so the added training improved respiratory outcomes without evidence of changing the scoliosis itself.
- Journal
- Respiratory medicine (Q1)
- Published
- 5 November 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Wenjing Zhu, Yuepeng He
- PMID
- 42988175
- DOI
- 10.1016/j.rmed.2026.109243
Why clinicians should know about it
- Picked for Rehabilitation (paper of the day, 7 November 2026): Combined IMT and Schroth yields greater respiratory improvements
Abstract
BACKGROUND: Adolescent idiopathic scoliosis (AIS) is associated with significant restrictive ventilatory impairment attributable to thoracic cage deformity and reduced respiratory muscle strength. Schroth physiotherapeutic scoliosis-specific exercise is an established conservative intervention, yet its impact on inspiratory muscle strength remains limited when applied alone. OBJECTIVE: To compare the effects of combined inspiratory muscle training and Schroth exercise against Schroth exercise alone on respiratory function, respiratory muscle strength, exercise capacity, and spinal deformity indices in adolescents with idiopathic scoliosis. METHODS: A single-blind randomised controlled trial enrolled 68 adolescents (aged 12 to 18 years) with confirmed idiopathic scoliosis and Cobb angle between 20 and 45 degrees. Participants were allocated 1:1 to either a combined IMT plus Schroth group (n=34) or a Schroth-alone group (n=34). Both groups completed 12 weeks of supervised Schroth exercise three times per week; the IMT group additionally performed threshold inspiratory muscle training at 30% of maximal inspiratory pressure, with load progression every two weeks. Outcomes assessed at baseline, six weeks, and twelve weeks included spirometry (FVC, FEV1, FEV1/FVC), respiratory muscle strength (PImax, PEmax), six-minute walk test distance, SpO2, Cobb angle (radiographic), and angle of trunk rotation (scoliometer). Mixed-model repeated-measures ANOVA was used for primary analysis. RESULTS: At twelve weeks, the IMT plus Schroth group demonstrated significantly greater improvements in FVC (79.1 vs 73.8% predicted; p=0.003), FEV1 (82.7 vs 76.5% predicted; p=0.001), PImax (84.7 vs 68.4 cmH2O; p<0.001), and PEmax (89.3 vs 72.6 cmH2O; p<0.001) compared with the Schroth-alone group. Six-minute walk test distance also improved significantly more in the IMT group (412 vs 385 m; p=0.018). Effect sizes for PImax and PEmax were large (Cohen's d 1.42 and 1.38 respectively). No significant between-group differences in Cobb angle or angle of trunk rotation were observed. CONCLUSIONS: Adding inspiratory muscle training to Schroth exercise produces clinically meaningful and statistically significant gains in respiratory function and muscle strength beyond those achievable with Schroth exercise alone. These findings support incorporating structured IMT into conservative physiotherapy programmes for adolescents with idiopathic scoliosis.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.