DEVELOPMENT OF NEW PROTOCOLS AND ANALYSIS PROCEDURES FOR THE ASSESSMENT OF LBP BY SURFACE EMG TECHNIQUES

Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assessed during a fatiguing isometric contraction can be used to classify different categories of low back pain (LBP) s ubjects and control subjects without LBP. In the test protocol current ly used at the NeuroMuscular Research Center at Boston University, sub jects contract their back muscles at 80% of their maximal voluntary co ntraction (MVC) force. This fatigue-based protocol has been successful ly applied to persons with subacute or chronic LBP; those in acute pai n, however, have not been included because of their inability to perfo rm a maximal exertion. In this paper we will examine the force sensiti vity of the currently used EMG parameters and also give an overview of some of our efforts to develop new test procedures. Our goal is to de velop force-insensitive surface EMG parameters that can be used for cl assification purposes in populations of subjects who develop low trunk extension forces. In addition, the development of a model to predict MVC from anthropometrical measurements will be presented.