Improved motor performance in chronic spinal cord injury following upper-limb robotic training

BACKGROUND: Recovering upper-limb motor function has important implications for improving independence of patients with tetraplegia after traumatic spinal cord injury (SCI). OBJECTIVE: To evaluate the feasibility, safety and effectiveness of robotic-assisted training of upper limb in a chronic SCI population. METHODS: A total of 10 chronic tetraplegic SCI patients (C4 to C6 level of injury, American Spinal Injury Association Impairment Scale, A to D) participated in a 6-week wrist-robot training protocol (1 hour/day 3 times/week). The following outcome measures were recorded at baseline and after the robotic training: a) motor performance, assessed by robot-measured kinematics, b) corticospinal excitability measured by transcranial magnetic stimulation (TMS), and c) changes in clinical scales: motor strength (Upper extremity motor score), pain level (Visual Analog Scale) and spasticity (Modified Ashworth scale). RESULTS: No adverse effects were observed during or after the robotic training. Statistically significant improvements were found in motor performance kinematics: aim (pre 1.17 +/- 0.11 radians, post 1.03 +/- 0.08 radians, p = 0.03) and smoothness of movement (pre 0.26 +/- 0.03, post 0.31 +/- 0.02, p = 0.03). These changes were not accompanied by changes in upper-extremity muscle strength or corticospinal excitability. No changes in pain or spasticity were found. CONCLUSIONS: Robotic-assisted training of the upper limb over six weeks is a feasible and safe intervention that can enhance movement kinematics without negatively affecting pain or spasticity in chronic SCI. In addition, robot-assisted devices are an excellent tool to quantify motor performance (kinematics) and can be used to sensitively measure changes after a given rehabilitative intervention.