Muscle atrophy after human spinal cord injury

The atrophy that accompanies muscle paralysis cannot always be accounted for by altered muscle use. Muscles innervated from spinal segments near a spinal cord injury also undergo denervation due to death of motoneurons. Intrinsic hand muscles are particularly vulnerable to complete denervation after human cervical spinal cord injury. Early intervention is needed to prevent muscle degeneration following denervation. Neuron replacement is one strategy to restore innervation to denervated muscles and to rescue muscle. Even if the muscles are not under voluntary control, reinnervated muscles can be activated electrically to generate simple functional behaviors.