Application of surface EMG topography in low back pain rehabilitation assessment

Lumbar musculoskeletal disorders were found to be one of the most common factors in Low Back Pain (LBP). Because of difficulties in the analysis and interpretation of surface electromyography (SEMG), specific muscular pathology associated with LBP continues to be debated. SEMG Topography is a novel method of visualizing the distribution of myoelectric signals during dynamic motion. SEMG topography provides a more comprehensive examination and contraction coordination insight into the fundamental muscular strategies. The purpose of this study was to assess the feasibility of SEMG topography as an assessment tool in LBP rehabilitation. Thirty healthy subjects were recruited to establish the normal database of SEMG topography pattern. Lumbar muscle activities were recorded during forward bending, by an array of SEMG electrodes applied over the low back area. The root mean square (RMS) of the SEMG signals was calculated in spatial distribution to produce topography of the muscle activity in the lumbar region. In addition, a preliminary clinical study was carried out with 5 LBP patients before and after LBP rehabilitation. In normal subjects, SEMG topography was consistent, reproducible, and reliable. In clinical observation, the SEMG topography of LBP patients was obviously different from normal pattern. However, after rehabilitation, SEMG pattern tended to return to normal pattern in some patients with pain released reported. The SEMG topography illustrates the distribution of muscle activities, which provides a visible result of lumbar muscles coordination. The results of this study suggested the use of SEMG topography as an objective assessment tool in LBP rehabilitation.