Introduction: Low back pain (LBP) is the leading cause of years lived with disability worldwide. Chronic LBP is associated with poor function and morphology of the paraspinal and gluteal muscles. Despite exercise therapy being recommended as a first-line conservative treatment for chronic LBP, many individuals harbour fear-avoidance beliefs that hinder their engagement in physical activities. Aquatic therapy reduces spinal loading, thereby increasing movement capacity and facilitating the execution of exercises that may be challenging on land. To our knowledge, no studies have examined the effects of aquatic therapy on paraspinal/gluteal strength and psychological outcomes. The study aims to investigate the effects of an aquatic therapy (AT) exercise intervention versus standard care (SC) on 1) paraspinal and gluteal strength and 2) patient-oriented outcomes including pain, disability, and psychological factors.
Methods: This pilot study is part of a larger ongoing randomized controlled trial; preliminary results are presented. A total of 17 participants aged between 18 and 65 and with moderate-to-severe non-specific chronic LBP were randomized to the AT (n=10) and SC (n=7) groups. Both groups completed a 10-week supervised intervention program (2 sessions per week). Lumbar extension and gluteal strength tests (i.e., MedEx and hand-held dynamometer) and self-reported questionnaires were acquired at baseline and post-intervention. Two-way repeated measures ANOVA was used to assess the changes in muscle strength and psychological outcomes within and between groups.
Results: There was a significant increase in gluteus medius strength from baseline to post-intervention in the aquatic therapy group (MD=125.97, p<0.001) compared to the standard care group (MD=54.00, p=0.06). Both groups significantly increased lumbar extensor strength (AT MD=47.0, p<0.001; SD MD=30.00, p=0.02) and gluteus maximus strength (AT MD=55.57, p=0.005; SC MD=52.19, p=0.02) across time points. The aquatic exercise group saw a significant decrease in pain (MD=-2.78, p<0.001), disability (MD=-18.0, p<0.001), pain catastrophizing (MD=-7.0, p=0.006) and kinesiophobia (MD=-4.88, p=0.03). The standard care group saw a significant decrease in pain (MD=-3.14, p <0.001), disability (MD=-14.57, p<0.001), and pain catastrophizing (MD=-9.14, p=0.002) with no difference across groups for all self-reported outcomes.
Discussion: This project provides valuable insight into the effects of aquatic therapy versus standard care on paraspinal and gluteal muscle strength, as well as patient-oriented outcomes. Notably, the aquatic therapy group demonstrated a significant increase in gluteal and lumbar extensor strength, highlighting its potential for enhancing muscle strength. These findings underscore the effectiveness of aquatic therapy in improving musculoskeletal health and well-being in individuals with chronic LBP.