The Step Related Phasic Modulation of Reflex in Individuals with Spinal Cord Injury---The Monitoring Index and the Effect of Modified Robot Assisted Stepping Training

The spinal circuitry undergoes immobilization adaptation after spinal cord injury (SCI). In the previous years’ project, we proved that the adaptation could be reversed by remobilization. The post activation adaptation (PAD) is an important function of spinal circuitry and is suggested to control the reflex excitability during postural and stepping tasks. However, the step related modulation of PADs is not clear. Afferent inputs generated by repeated joints motions are considered to be important in spinal circuitry plasticity. The repeated ankle joint motions have been proved to be related to the reduction of spasticity. However, the current robot-assisted exoskeleton gait rehabilitation system, such as Lokomat, does not control the ankle joint angle which has been reported to induce abnormal spasticity during gait. Therefore, using a modified robot-assisted gait training system that can control the ankle joint is important in the rehabilitation of the step related phasic modulation of the spinal circuitry. Elliptical machine which uses end-point control theory is optimal to quantify ankle movements during robot-assisted gait training. In this project, we will establish the step related phasic modulation indexes for spinal circuitry, establish patients selection criteria, and evaluate the training effect of elliptical machine based robot-assisted gait training. Purposes: Year 1: to establish the step related phasic modulation of H reflex and PAD motoring indexes. Year 2: to investigate the different adaptations of the step related phasic modulation of H reflex and PAD after different types of spinal cord injuries. Year 3: to investigate the effect of long term stepping training on recovery the step related phasic modulation of H reflex and post activation depression in individuals with SCI. In the first year, the indexes of the step related phasic modulation of spinal circuitry will be established. The modulation pattern on the treadmill and elliptical machine will be compared. In the second year, the step related phasic modulation of H reflex and PAD will be evaluated on SCI patients with different ASIA classifications. In the third year, the the effect of modified robot assisted stepping training will be evaluated and will be compared with the long term non-phasic passive motion training. The result of this project will advance the knowledge on the mechanism and rehabilitation of functional plasticity of spinal circuitry and provide naval clinical rehabilitation for individuals with SCI.

Project ID:PC10501-1875
External Project ID:MOST104-2314-B182-007-MY3