Student Competition (Technology Innovation) ID 1985155

ISMS entails implanting micro-electrodes into the spinal cord to produce synergistic activations of the legs. To date, ISMS has produced in-place stepping in cats with complete spinal cord injury (SCI) (Saigal et al, 2004), and long distances of over ground walking in anesthetized cats (Holinski et al, 2016). The goal of this project is to develop an intervention for restoring overground walking capacity for persons experiencing paralysis due to SCI, by investigating the potential of ISMS to enable long-distance overground walking in cats with chronic SCI. Experiments will be performed in eight adult cats with chronic complete SCI. The control strategy will include timed transitions between different phases of the step cycle, which will be modified using feedback from force plates and gyroscopes. The biomechanics of walking (speed of walking, stride length, left-right symmetry, inter-joint coordination) and muscle activation patterns will be recorded and analyzed. The stride-to-stride regularity of walking, amount of weight-bearing, and level of spasticity before, during, and after ISMS will be assessed. We expect that ISMS will produce long distances of walking (>500 m) in cats with SCI. The biomechanical features of walking will be similar to those in neurologically-intact cats. This project is a critical step towards demonstrating the viability of ISMS as a means for restoring functional walking after severe SCI. If successful, ISMS and the control strategies developed may in the future change the lives of many people living with SCI, giving them the capability to walk independently.