Introduction: Non-specific chronic lower back pain (NSCLBP) is a global health concern due to its high prevalence, and associated economic and social burden (1). NSCLBP is suggested to be the consequence of multiple risk factors, notably reduced muscular strength and flexibility, and lack of aerobic exercise (AE). It is suggested that whilst interventions individually targeting these risk factors are effective in reducing NSCLBP, a multidisciplinary approach targeting all three components may be more effective (2). The aim of this study was to determine the effects of a combined exercise programme involving AE (running), and muscle strengthening (MS) and flexibility exercise (FE) (in the form of Ashtanga yoga), for runners with NSCLBP.
Methods: A Randomized-controlled study was conducted over 6 weeks, on recreational runners suffering from NSCLBP aged 18-65. The control group was required to continue their usual exercise routine, while the intervention group was required to complete a combined exercise programme involving AE (minimum of 75minutes of running per week, or alternatively 150minutes of walking or cycling per week, if pain prevented running), and MS/FE in the form of Ashtanga yoga. Outcome measures were the Visual analogue scale (VAS) for their back pain and Oswestry disability index (ODI).
Results: 29 participants took part in the study (14 control group, 15 intervention group; 65.5% female; mean age 48.8; mean BMI 23.9 kg/m2). The dropout rate was 26.7% intervention group and 14.3% control group. Mean VAS at baseline was 3.9cm intervention and 3.9cm control group; and was 3.4 and 4.1 respectively at follow-up. Mean ODI score at baseline was 16.0% intervention and 14.0% control group; and was 14.0% and 12.0% respectively at follow up. There was no statistically significant difference between baseline and follow-up VAS and ODI scores within both groups (p>0.05). There was no statistically significant difference in VAS or ODI scores between both groups, both at baseline and follow-up (p>0.05).
Discussion: This study demonstrated that a 6-week combined exercise programme involving AE, and MS and FE in the form of Ashtanga yoga, did not have a significant impact on runners suffering from NSCLBP. MS and FE are long-term solutions targeting core strength, and hip and lumbar muscle flexibility, to ensure proper running biomechanics and distribution of mechanical load, to reduce stress on the lumbar spine. The limited duration of the study and yoga sessions, intensity of the programme, and/or the small sample size may have been insufficient to allow significant physiological adaptations. Moreover, the content of the programme may not have targeted the appropriate risk factors.
Future studies shall seek to conduct double-blinded RCT on a larger scale, for a minimum of 8 weeks with subsequent follow-up measurements to investigate long-term effects of the programme, and adherence rates. Further investigation is required regarding specific exercises that are most effective in improving NSCLBP. Screening for specific risk factors would guide the designing of an individualised and more targeted approach. Including objective measures such as strength and flexibility testing, would provide higher-level direct evidence on the effects of exercise therapies on NSCLBP.