The effect of Aqua Stretching exercises and Pilates on pain, function and spine posture in patients with ankylosing spondylitis: a randomized controlled trial

Background Aqua Pilates and Aqua Stretch exercises are different and new methods for the rehabilitation of musculoskeletal disorders. This study aimed to compare the effectiveness of Aqua Stretch and Aqua Pilates interventions in the treatment of pain, function, and posture of the spine in ankylosing spondylitis (AS) patients. Methods Forty patients participated in this study who were randomly allocated into Aqua Stretch, aqua Pilates, and control. The experimental groups received four 60-min training sessions each week for six weeks. However, the control group had only its routine drug treatment (NSAIDs & Anti TNF). Pain with Visual Analog Scale (VAS), function with Bath Ankylosing Spondylitis Functional Index (BASFI) and 40-m walking test (MWT), quality of life with ankylosing spondylitis quality of life (ASQoL), and posture of the spine with the Spinal Mouse were evaluated. Evaluations were performed before and after the interventions. Repeated measure ANOVA was employed to determine the main and interaction effects. Results Aqua Stretch and Aqua Pilates had a significant effect on pain (Aqua-Pilates: P = 0.0001; Aqua-Stretch: P = 0.0001), BASFI (Aqua-Pilates: P = 0.01; Aqua-Stretch: P = 0.02), 40-MWT (Aqua-Pilates: P = 0.006; Aqua-Stretch: P = 0.0001) and ASQoL (Aqua-Pilates: P = 0.01; Aqua-Stretch: P = 0.001), spinal range of motion (ROM) (Aqua-Pilates: P = 0.0001; Aqua-Stretch: P = 0.0001) at a similar ratio. However, the control group did not present any improvement in these factors (P > 0.05). Moreover, the minimal clinically important difference (MCID) revealed that the Aqua Stretch group performed better than the Aqua Pilates group in terms of VAS, ASQOL, and 40-MWT factors. Conclusions Aqua Stretch and Aqua Pilates had statistically the same effect on improving pain, function, quality of life, and spinal ROM, while MCID results revealed that the Aqua Stretch group performed better than the Aqua Pilates in terms of VAS-ASQOL-40-MWT. Trial registration It is notable that local ethics committee approval was obtained (IR.KUMS.REC.1399.1137), and the study was registered in Iranian Registry of Clinical Trials (IRCT; IRCT20190426043377N3; registered on 22/05/2021, Keywords: Ankylosing spondylitis, Aqua exercises, Stretch, Pilates, Pain, Function, Quality of life, Spine