AbstractChronic low back pain (CLBP) is a common health problem resulting in high level of disability. It places a significant financial and social burden on individuals as well as society. Pilates exercise is effective in reducing pain and disability in people with CLBP in the short term. Meanwhile, conflicting results have been reported in the long term, and the impact of Pilates on psychosocial and physical factors is not clearly understood.
The Primary aim of this randomised controlled trial (RCT) was to determine the effectiveness of Pilates compared to usual care on pain and disability in the short term (12 weeks) while the secondary aim was to determine the effects of Pilates on psychosocial and physical factors in people with CLBP. Eighty-four adults with CLBP were randomly allocated to Pilates or a “usual care” group. Participants in the Pilates group attended 60 minutes of supervised sessions twice per week for 12 weeks. Participants in the usual care group continued their usual level of physical activity and medication use. Primary outcomes included pain (Numerical Rating Scale) and disability (Oswestry disability Index), while secondary outcomes included psycho-social factors (Fear-Avoidance Belief Questionnaire, Tampa Scale of Kinesiophobia) and physical factors (Lumbar spine active range of movement, back extensor endurance, core stability, and motor control). Assessors were blinded to allocation. The effect of the intervention was examined by using a linear mixed model analysis. Intention to treat analysis was conducted using the last observation carried forward.
To measure the motor control impairments associated with CLBP new physical tests of motor control were developed. A pilot study was therefore conducted prior to the RCT to test the intra-rater and inter-rater reliability of these newly generated physical tests, as well as other physical outcome measures to be utilised in the trial. Ten healthy adults were assessed by two blinded assessors over two days. The physical tests included lumbar spine flexion, extension, and lateral flexion range of movement (Modified-modified Schober's test), modified finger to floor test), back extensor endurance (Ito’s test), and core stability (Sahrmann’s core stability test). Newly designed motor control tests included the following: graded active straight leg raise, graded prone leg raise, graded plank, and graded side plank. The intra-rater and inter-rater reliability demonstrated good to very good reliability for Sahrmann’s test (AC2 = 0.89-1.0), moderate reliability for lumbar spine range of motion (ICC = 0.63-0.99) and back extensor endurance (ICC = 0.48-0.71). Some of the newly generated tests were highly reliable: graded active straight leg raise (AC2 = 0.84-0.93), and graded plank (AC2 = 0.71-0.85), but graded prone leg raise (AC2 = 0.18-0.95) and graded side plank (AC2 = 0.02-0.69) were poor to moderately reliable. Back extensor endurance, graded prone leg raise and graded side plank measures should be used with caution. Future research should explore the reliability of these measures in people with CLBP.
A total of forty-eight participants completed the randomised controlled trial. There were 36 participants lost to follow up (43%). Only 12 week findings were available at the time of writing this thesis. At 12 weeks, Pilates provided improvements over usual care in disability with a difference of 6.7 points on the Oswestry Disability Index (p = 0.012), and a reduction in pain of 0.9 points with the Numerical Rating Scale (p = 0.006). No improvements were observed in psychosocial measures, lumbar spine range of movement, Ito’s test of back endurance, and graded plank test. There were, however, some aspects of physical measures that showed improvement in the Pilates exercise group at 12 weeks, including Sahrmann’s core stability test, graded prone leg raise and graded active straight leg raise.
Findings in this RCT were similar to previously reported studies with improvements in pain and disability at 12 weeks. Improvements in core stability and motor control may indicate a possible mechanism of improvement in pain and disability with Pilates exercise. Furthermore, our RCT confirmed no improvement in psychosocial factors, lumbar spine range of movement and back extensor endurance. Despite statistically significant improvements, changes in pain and disability were not clinically significant however, so findings need to be interpreted with this in mind. Lack of clinical significance may relate to the high drop-out rate and conservative findings obtained using intention-to-treat analysis. Future research trials need to consider how to maintain adherence, and cost-benefit of Pilates over other forms of exercise if equivalent improvements are obtained. Subsequent analyses of findings at 26 weeks may also assist in understanding any potential longer term benefits of Pilates exercise in people with chronic low back pain.
|Date of Award
|Stuart Semple (Supervisor) & Cherie Wells (Supervisor)