The relationship between EMG activity of the Sacrospinalis and reported back discomfort

Six subjects performed a tapping task during replicated pairs of trials involving three different degrees of forward bend. The first and second trial of each pair was separated by either a 4 min or 1 min rest period. Integrated electromyographic (IEMG) records from the right Sacrospinalis muscle and estimates of back discomfort on a 5 point scale at 1 min intervals were collected. Reported back discomfort did not correlate with I.E.M.G. Increased forward bend and reduced rest interval generally led to increased levels of reported discomfort but not necessarily increased I.E.M.G.