The control of muscles by the nervous system underlies all of our actions. This control requires constant modulation of the output from the motor areas of the brain to produce voluntary movements plus feedback from sensory receptors in the limbs to allow adaptation to changing conditions. Muscle fatigue with exercise is a common experience in healthy people. It is a prominent symptom in people with many kinds of illnesses, including neurological, musculoskeletal, cardiorespiratory, psychiatric and other debilitating disorders. Although processes in the muscle cause some of the weakness of fatigue, processes in the nervous system also contribute to weakness, as well as providing the sensations of fatigue. Understanding the contribution of the nervous system to fatigue will allow better management of this symptom in illness. In addition, study of the nervous system during exercise and fatigue gives insight into the processes by which the motor system adapts to allow successful interaction with the environment.
Janet Taylor (MBBS, MBiomedE, MD) received her doctorate for research in neurophysiology from the University of New South Wales in 1991 and was a postdoctoral fellow at the University of Alberta, Edmonton and at the Institute for Neurology, Queens Square, London. She has been at POWMRI since 1993. Her interests include proprioception, which includes the sensations related to position, movement and forces produced by or imposed on the body, and the neural control of human movement, particularly during muscle fatigue.
