The ability to noninvasively assess voluntary muscle effort has wide application in physiologic studies, sports and rehabilitation medicine, as well as movement science. Traditionally, surface electromyography (sEMG) has been used for such assessments, but sEMG has several significant limitations arising from the fact that an estimate of muscle mechanical effort is being obtained from an electrical potential measurement made at the skin surface. As a result, it can be difficult to compare recordings from different muscles on the same person, on the same muscle over a period of days or weeks, or between the same muscle on different individuals. In addition, muscle fatigue studies are difficult as EMG activity tends to increase with increasing fiber recruitment, even though muscle effort is decreasing.

To overcome the limitations associated with using sEMG recordings to evaluate muscle effort, an increasing number of investigators have come to rely upon vibromyography (VMG), or the recording of muscle fiber vibrations, to estimate muscle effort levels2. The development of microelectromechanical (MEMS) accelerometers has contributed greatly to this transition as extremely sensitive, very low noise sensors are now available at reasonable cost.

Click for Vibromyography: Assessing voluntary muscle effort