Immobilization impairs recovery after spinal cord injury

The effect of immobilization on motor recovery was studied in adult rats after subtotal spinal cord section. Anesthetized rats underwent three-quarter section of the cord, sparing the left lateral funiculus. After surgery, half the rats were placed in immobilization tubes for three to four weeks; the others were allowed free mobility. Hindlimb motor function was graded at various times in the two groups. In contrast to the marked recovery observed in mobile animals, the immobilized rats with similar cord lesions showed no significant motor recovery during the period of immobilization. Immobilized rats without cord lesions showed minimal transient deficits. In conclusion, hindlimb activity appears to be a necessary condition for motor recovery after subtotal spinal cord injury.