Effects of Eccentric Strengthening on Force Output of the Erector Spinae as Measured by Surface Electromyography (EMG)

The purpose of this study was to determine the increase in force output of the erector spinae using the mean amplitude of surface electromyography (EMG) before and after an eccentric exercise program. Eight healthy subjects, two men and six women, between the ages of 30-45 were individually dosed and evaluated for baseline recordings of their EMG activity during three isometric and six eccentric contractions of their lumbar erector spinae. The exercise program consisted of a single eccentric lowering exercise of six repetitions for three sets, two times a week, for four weeks. EMG recordings were taken in post-test measurements during three isometric and six eccentric contractions at the end of the study. Pretest and post-test data were compared using the Wilcoxon signed rank test for paired data (α = 0.05). There is insufficient evidence to conclude that a four week eccentric training protocol had an effect on the force output of the erector spinae as measured by surface EMG.