Abstract
BACKGROUND: In this study, we aimed to create a rat model of incomplete spinal cord injury and to determine the relationship between muscle tone and gait characteristics during recovery from paralysis. This necessity stems from the need for animal models with motor function dynamics in rehabilitation development for spinal cord injury. METHODS: Thirty-eight-week-old male Sprague-Dawley rats were divided randomly into two groups: Sham and spinal cord injury groups. Three-dimensional gait analysis, Hoffman reflex, Basso-Beatie-Bresnahan score, muscle wet weight, and histological assessment were performed on postoperative days 3, 7, and 14, respectively. RESULTS: The incomplete spinal cord injury model showed paralysis recovery over time at postoperative day 14. At ground contact, the ankle plantar flexion angle was higher in the spinal cord injury group than in the Sham group on postoperative day 3; however, it reduced on postoperative day 14. Nevertheless, the ankle plantar flexion angle on the foot-off phase was significantly higher on postoperative days 3 and 14. The ankle abduction angle in the spinal cord injury group significantly increased over time and was higher than in the Sham group at all time points. Hoffmann reflex results showed that muscle tone was significantly higher in the spinal cord injury group on postoperative day 3 and increased over time. The model's gait was significantly affected by muscle tone changes. CONCLUSION: The model provides a valuable tool for studying spastic gait and gait changes associated with improvement in paralysis.