Neuromuscular changes of abdominal and lumbar muscles following exercise for chronic non-specific low back pain

Abstract

Low back pain (LBP) is a prevalent physical, social, economic problem in developed countries. Past research has shown exercise to be a favourable treatment, but the most successful mode of exercise for LBP is unknown. This study compared 8 weeks of specific, general forms of exercise in chronic non-specific low back pain (CNSLBP) individuals. Surface electromyography (sEMG) was used to measure the abdominal, lumbar muscle onset times of the central nervous system (CNS) in a rapid unilateral arm movement. Self-reported disability, pain were also measured. It was hypothesised that there would be a decrease in muscle onsets following specific exercise, no change in onsets following general exercise. Neither hypothesis was supported, as neuromuscular changes were observed following both general, specific exercise with no between-group differences identified. Muscle onsets were found to change in the direction of the prime mover. This change was proposed to be an adaptation of the CNS to produce more coordinated neuromuscular responses following each intervention. Contrary to past research, no delays in muscle onsets in LBP were identified. Side-specific changes were also found in muscle onsets, with the contralateral side activating prior to the ipsilateral side. Disability was reduced after specific exercise only, but pain was reduced following both interventions. A possible rationale for the lack of treatment effects observed in this study includes common adaptations of the CNS underpinning the success of any form of appropriately prescribed exercise. Moreover, muscle onsets may be a neuromuscular marker of this adaptation. Future studies are required to replicate these findings, further investigate the relationship between pain, neuromuscular responses of the CNS. Low back pain (LBP) is a prevalent physical, social, economic problem in developed countries. Past research has shown exercise to be a favourable treatment, but the most successful mode of exercise for LBP is unknown. This study compared 8 weeks of specific, general forms of exercise in chronic non-specific low back pain (CNSLBP) individuals. Surface electromyography (sEMG) was used to measure the abdominal, lumbar muscle onset times of the central nervous system (CNS) in a rapid unilateral arm movement. Self-reported disability, pain were also measured. It was hypothesised that there would be a decrease in muscle onsets following specific exercise, no change in onsets following general exercise. Neither hypothesis was supported, as neuromuscular changes were observed following both general, specific exercise with no between-group differences identified. Muscle onsets were found to change in the direction of the prime mover. This change was proposed to be an adaptation of the CNS to produce more coordinated neuromuscular responses following each intervention. Contrary to past research, no delays in muscle onsets in LBP were identified. Side-specific changes were also found in muscle onsets, with the contralateral side activating prior to the ipsilateral side. Disability was reduced after specific exercise only, but pain was reduced following both interventions. A possible rationale for the lack of treatment effects observed in this study includes common adaptations of the CNS underpinning the success of any form of appropriately prescribed exercise. Moreover, muscle onsets may be a neuromuscular marker of this adaptation. Future studies are required to replicate these findings, further investigate the relationship between pain, neuromuscular responses of the CNS.