Addition of forelimb training reduces gains from robotic gait training in a rat model of spinal cord injury

• Main Authors: Neckel, Nathan D., Haining Dai, Rodriguez, Olga C.
• Format: Conference Proceeding
• Language: English
• Subjects: Animals; Conferences; Exercise Therapy; Female; Forelimb - physiopathology; Gait - physiology; Rats; Rats, Sprague-Dawley; Recovery of Function - physiology; Rehabilitation robotics; Robotics - methods; Spinal Cord Injuries - physiopathology; Spinal Cord Injuries - rehabilitation
• ISSN: 1945-7901
• DOI: 10.1109/ICORR.2017.8009271

To restore locomotor function following spinal cord injury the disrupted descending supraspinal drive needs to be re-connected to regions caudal to the injury. Robotic gait training aims to facilitate recovery by stimulating the proprioceptive networks of the legs in a coordinated walking pattern while the descending supraspinal connections are re-established. In incomplete injuries, it is believed that the interneuronal networks near the injury site form relay circuits to reroute the supraspinal signals through the spared tissue. Stimulating these neurons should lead to increased arborization, and more robust relay circuits. We set out to show that robotic gait training is more effective when it is paired with training that activates interneurons at the level of the injury. Following a C4/5 over-hemisection injury the addition of skilled forelimb training actually reduced the gains found with robotic gait training alone. Not just gains within the training device, but also in independent overground locomotion. MRI imaging shows that skilled forelimb training reduces cellular activity, and reduces the organization of the axonal tracks at the injury site. This may be evidence that spared interneurons have limited resources and/or ability in establishing relay circuits to route supraspinal drive around the injury site. Skilled forelimb training and robotic gait training may not be synergistic, but competitive rehabilitative tasks.