Grant: Discovery Grants Program - Individual

A motor unit is defined as a single alpha motor neuron and all the muscle fibers that it innervates. It is the fundamental unit of force generation in skeletal muscle. The electrical activity generated by motor unit action potentials reflects nervous system control of skeletal muscle and may be monitored directly by indwelling wire or needle electrode. Unfortunately, indwelling techniques are invasive and painful. The overarching theme of the research program is to understand what information about human motor unit activity patterns is contained within the surface electromyographic (EMG) signal during voluntary contractions. This problem is difficult because muscle electrical activity generated during voluntary contractions results in a complex interference pattern that masks the activity of individual motor units. The ultimate goal is to develop a non-invasive technique for monitoring changes in motor unit activity patterns associated with injury to the neuromuscular system and its rehabilitation. The specific short-term objectives involve a series of studies to refine and validate surface electromyographic analysis as a non-invasive way to monitor motor unit activity. This research program has both basic and applied significance. The studies outlined in this proposal will provide a better understanding of motor unit firing patterns that underlay the gradation of muscle force. The research program is also highly translational and has broad application across many disciplines that use surface electromyography to assess and/or understand the neuromuscular system.