The objective of this study was to identify how activity patterns of trunk muscles change in chronic LBP during walking. Type A systematic review Literature survey ELSEVIER, Pro Quest, PubMed, Google scholar and MEDLINE electronic databases were explored for the earliest researchable time to August 2014 period. Articles investigating patients with chronic LBP and analyzing trunk muscles with surface electromyography (EMG) during walking were included. All studies had a case-control design. Characteristics of the LBP patients, sample size, studied muscles and EMG parameters, gait condition and velocity were investigated. Studies were rated as “A” to “E” (five grades defined) based on study design and performance. Multifidus (MF), erector spinae (ES), external oblique (EO) and rectus abdominus (RA) muscles activity level were found to be increased in LBP subjects in comparison with controls. ES activity in low back pain subjects was found not to be so adaptive to walking velocity alterations such as in healthy controls.
Chronic LBP subjects display higher global trunk muscles activity. However, the activation pattern seems to vary depending on sub-phases of gait. It seems that increased walking velocity challenges the stability of the spine and the control system increases muscular activation and variability level to cope with this problem. Further standardized studies with sub-typed LBP cases are necessary to clarify the controversial findings.