Journal:Muscle and Nerve
Year, Volume, Issue, Page(s):15, 51, 2, 235-245
Study examined muscle activation during single and repeated isometric, concentric, and eccentric knee extensor (KE) maximal voluntary contractions (MVCs) to better understand volitional force generation after chronic incomplete spinal cord injury (SCI). Torque and electromyographic (EMG) activity were recorded during single and repeated isometric and dynamic KE MVCs in 11 subjects with SCI. Central activation ratios (CARs) were calculated for all contraction modes in subjects with SCI and 11 healthy controls. Results showed that subjects with SCI generated greater torque, EMG, and CARs during single eccentric versus isometric and concentric MVCs. This pattern of activation contrasts with the decreased eccentric activation demonstrated by healthy controls. Torque and EMG remained similar during repeated eccentric MVCs; however, both increased during repeated isometric and concentric MVCs. The findings from this study may aid development of novel rehabilitation interventions.