Introduction
Therapeutic exercise is one of the most recommended conservative treatments for patients with adult spinal deformity (ASD). Although the benefits of back muscle strengthening exercises have been reported, their effectiveness in improving quality of life (QOL) and physical function remains unclear. This study aimed to investigate whether therapeutic exercise improves patient-reported outcomes and to identify risk factors predictive of treatment failure.
Methods
This retrospective cohort study included 52 female ASD patients with back pain, with a mean age of 70.8 years. ASD was defined according to the SRS-Schwab classification. All patients participated in an outpatient-based therapeutic exercise program lasting over 3 months, consisting of a weekly 40-minute session at the clinic and home-based exercises at least 3 days per week. The program aimed to improve muscle strength, endurance, and range of motion (ROM) in the trunk and lower extremities. The primary outcome measures were the Oswestry Disability Index (ODI) and the Numeric Pain Rating Scale (NRS). Treatment success was defined as achieving a minimal clinically important difference (MCID) based on previous studies: an improvement of at least 10 points in ODI and 20 points in NPRS. Secondary outcome measures included physical function, specifically muscle strength and ROM of the trunk and hip joints. Statistical analysis was conducted using the Wilcoxon signed-rank test to compare pre- and post-treatment results, and logistic regression analysis was performed to identify risk factors predictive of treatment failure. A p-value of less than 0.05 was considered statistically significant.
Results
Significant improvements were observed in both ODI and NPRS. Twenty-four patients (46.2%) achieved the MCID for ODI improvement. Severe sagittal vertical axis (SVA), restricted lumbar extension ROM, and hip extension ROM were predictive of treatment failure for ODI. Twenty-seven patients (51.9%) met the MCID for NPRS improvement, with severe SVA identified as a predictor of treatment failure.
Discussion
This study demonstrated that therapeutic exercise was effective in achieving clinically meaningful improvements in QOL and back pain in approximately 50% of patients with ASD. These effects may be attributable to improvements in physical function, including muscle strength and ROM. Risk factors for treatment failure included severe SVA, limited lumbar extension ROM, and hip extension ROM.