This proposal will develop a FES-augmented recumbent stepper that elicits lower extremity involvement through electrical stimulation while upper extremity involvement is volitionally controlled by the client. Exercise for people with spinal cord injury not only enhances physical fitness but has the potential to slow or reverse many of the secondary complications of SCI such as diabetes, cardiovascular disease, respiratory complications, pressure sores and osteoporosis. Currently available SCI exercises, however, are generally targeted at the lower extremities and provide no opportunity for a concurrent lower and upper extremity exercise. In order to address this SCI exercise limitation, we propose to augment a NuStep TRS4000, a recumbent cross trainer that provides a coupled reciprocal leg/arm extension exercise movement, with functional electrical stimulation (FES). The FES component will exercise the lower extremity musculature at a comparable intensity to the client's volitional upper extremity input such that an enhanced cardiorespiratory exercise opportunity is provided to the patient compared to other SCI exercise opportunities. We hypothesize that the FES component may improve both efficacy and availability of TRS4000 exercise for a significant percentage of potential users. We anticipate that successful implementation would lead to a viable commercial product which would meet a clinically relevant need and build upon existing clinical acceptance of the NuStep device. The goals of this Phase I project are: 1) to modify and instrument a NuStep TRS4000 for FES-exercise following complete paraplegia due to SCI;2) to develop KaiSTIM autonomous stimulation control algorithms for recumbent stepping via FES;3) to demonstrate feasibility of FES-augmented TRS4000 exercise following SCI through a pilot study that will be performed in the Neuromotor Rehabilitation Research Laboratory at the Miami Project to Cure Paralysis (Miami, FL) under the direction of Edelle Field-Fote, PhD, PT. The feasibility study will include recruitment of five (5) subjects with complete paraplegia due to spinal cord injury who will each participate in three (3) sessions of FES-augmented NuStep exercise. Feasibility will be defined as the ability for the stimulation control algorithms to develop client-specific stimulation patterns to generate lower extremity contributions in synchronization with volitional upper extremity involvement across subjects and visits without the intervention of therapists or research engineers. The target market for the device will be rehabilitation clinics that provide care to individuals with complete paraplegia due to spinal cord injury and direct sales to clients for continuing exercise at home. customKYnetics, Inc. will seek a Strategic Alliance partnership with NuStep, Inc. for manufacturing, marketing, sales, and distribution of the FES-augmented TRS4000 with the goal of achieving a price point of $5000.
The proposed work may benefit health through development of an electrical stimulation augmented recumbent stepping device (TRS4000;NuStep, Inc.) indicated for exercise following spinal cord injury (11,000 cases per year). Compared to the stand-alone NuStep device, the electrical stimulation component may improve efficacy of the exercise for users with limited or no volitional control and may improve availability of the exercise for individuals with insufficient volitional control to otherwise participate.