The Journal of Neurophysiology Vol. 86 No. 4 October 2001, pp. 1764-1772
Copyright ©2001 by the American Physiological Society

Greater Movement-Related Cortical Potential During Human Eccentric Versus Concentric Muscle Contractions

 ¹Department of Biomedical Engineering, Lerner Research Institute;  ²Department of Physical Medicine and Rehabilitation, The Cleveland Clinic Foundation, Cleveland 44195; and  ³Program of Applied Biomedical Engineering, Fenn College of Engineering, Cleveland State University, Cleveland, Ohio 44114

Fang, Yin, Vlodek Siemionow, Vinod Sahgal, Fuqin Xiong, and Guang H. Yue. Greater Movement-Related Cortical Potential During Human Eccentric Versus Concentric Muscle Contractions. J. Neurophysiol. 86: 1764-1772, 2001. Despite abundant evidence that different nervous system control strategies may exist for human concentric and eccentric muscle contractions, no data are available to indicate that the brain signal differs for eccentric versus concentric muscle actions. The purpose of this study was to evaluate electroencephalography (EEG)-derived movement-related cortical potential (MRCP) and to determine whether the level of MRCP-measured cortical activation differs between the two types of muscle activities. Eight healthy subjects performed 50 voluntary eccentric and 50 voluntary concentric elbow flexor contractions against a load equal to 10% body weight. Surface EEG signals from four scalp locations overlying sensorimotor-related cortical areas in the frontal and parietal lobes were measured along with kinetic and kinematic information from the muscle and joint. MRCP was derived from the EEG signals of the eccentric and concentric muscle contractions. Although the elbow flexor muscle activation (EMG) was lower during eccentric than concentric actions, the amplitude of two major MRCP componentsone related to movement planning and execution and the other associated with feedback signals from the peripheral systemswas significantly greater for eccentric than for concentric actions. The MRCP onset time for the eccentric task occurred earlier than that for the concentric task. The greater cortical signal for eccentric muscle actions suggests that the brain probably plans and programs eccentric movements differently from concentric muscle tasks.