Paper Title
LOWER LIMB DOF CONSTRAINTS AND CHANGES IN WHOLE BODY MUSCLE ACTIVITY DURING STANDING UP IN ACUTE STROKE PATIENTS

Abstract
Acute stroke patients, whose motor control systems in the central nervous system may not be compensatory for motor paralysis, may be an appropriate model to examine the immediate adaptability of the motor control system to physical changes in the body, such as the addition of assistance. Six acute stroke patients performed a standing movement. Experimental conditions were with and without knee braces. An inertial measurement device and a surface electromyograph were used as the measurement devices. The section of the standing up movement was extracted, and the amount of activity at the time of the moment of the withdrawal and the integral value of the amount of activity up to the moment of the withdrawal were calculated for each muscle. The above parameters were compared between experimental conditions. Results showed that changes in whole-body muscle activity when the distal node force was compensated by the brace differed from patient to patient. Excessive energy expenditure from the trunk muscles was suppressed in patients with good postural control (i.e., trunk in more extended position in the sitting position). On the other hand, patients with poor postural control (i.e., trunk in more flexed position in sitting) had increased trunk muscle activity with distal lateral stability. Changes in whole-body muscle activity in response to lower limb DOF constraints, i.e., control simplification, were expected to vary depending on the trunk function possessed by the patient, as well as changes in the central nervous system motor control system. Keywords - Stroke, Motion Capture, Orthosis, Motion Control