Forelimb Force Deficits and Whole Body Compensations after Rat Cervical Spinal Hemisection

Incomplete cervical lesion is the most common type of human spinal cord injury (SCI) and causes permanent paresis of arm muscles, a phenomenon still incompletely understood in physiopathological and neuroanatomical terms. We performed spinal cord hemisections in adult rats at the caudal part of the segment C6, and analysed the forces and kinematics of locomotion up to four months post-injury to determine the nature of motor function loss and recovery. A severe (50 %), immediate and permanent loss of extensor force occurred in the forelimb but not in the hindlimb of the injured side, accompanied by elbow and wrist kinematic impairments and early adaptations of whole-body movements that initially compensated the balance but changed continuously over the follow-up period to allow effective locomotion.