Evaluation and assessment of non-specific lower back pain in the sub-acute phase. Effectiveness of a web-based exercise program in office workers suffering from sub-acute non-specific low back pain

Resumen

Lower back pain has in most cases an unknown origin and affects individuals¿ quality of life, their family and social relationships, and their ability to and capabilities at work. In Spain this problem has significant economic consequences. It is estimated that the total annual average cost of episodes of sickness absence caused by lower back pain surpasses 195 million euros per year, the bulk of which is due to the condition becoming chronic among those who suffer from it. Experts acknowledge the need to manage this ailment, and scientific evidence has demonstrated that physical exercise helps improving health-related quality of life among affected individuals and reduces the socio-economic impact from the disease. We propose that a cost-effective and efficient strategy to deal with this could rely on web-based interventions at the workplace, which have been shown to be effective in improving fitness levels and promoting an active lifestyle among the general population. However, no studies have addressed the effects of these interventions on subjects who experience lower back pain. Besides, there is currently no available tool to test the risk of chronicity of non-specific lower back pain in Spain and no data at all on fitness and quality-of-life profiles or on trunk muscle endurance for workers affected by this condition. Gathering such data is of uttermost importance for the assessment and monitoring of lower back pain among this population. The aims of this thesis are threefold. Firstly, we investigate and adapt the English Start Back Screening Tool for its potential use in the assessment of the risk of chronicity in non-specific lower back pain in Spain. Secondly, we explore the fitness and quality-of-life profiles of office workers affected by sub-acute, non-specific lower back pain and the validity of the well-established Ito¿s trunk muscle endurance test for this subpopulation. Thirdly, we test the effectiveness of a nine-month web-based intervention consisting of exercise and postural education on key lower back pain associated outcomes. Our global sample is composed of 228 office workers from a Spanish university, out of which 137 had been diagnosed with sub-acute, non-specific lower back pain at recruitment. Our treatment is the above mentioned web-based exercise programme and postural education intervention and our outcome measures are musculoskeletal-related fitness, clinical characteristics associated with lower back pain, and the number of episodes of lower back pain at baseline and after nine months. Key results indicate that the use of the Start Back Screening Tool can be extended to the Spanish population and that office workers affected by sub-acute, non-specific lower back pain have poorer fitness and quality-of-life profiles than age-matched office workers without this condition. They also show that Ito¿s lumbar trunk muscle endurance tests is valid and reliable for use among office workers with sub-acute, non-specific lower back pain and that the intervention we propose enhances quality-of-life, functional and lumbar trunk muscle endurance capacity, and decreases the risk of chronicity and non-specific lower back pain episodes. Overall, the contents of this thesis advance knowledge on the evaluation and assessment of patients with sub-acute, non-specific lower back pain, contribute to the literature on the adaptation of assessment instruments to the Spanish context, and provide important practical insights on how health-related policy could tackle lower back pain through web-based re-education interventions.