The proposed research will attempt to design and construct a closed-loop control system for stabilizing antero-posterior postural sway at the ankle joint in paraplegic individuals standing by functional neuromuscular stimulation (FNS). The research is limited to the specific problem of quiet standing within narrow limits which are defined by contraints such as stabilization of the hip and torque available from electrically stimulated muscle. Mathematical models of upright posture will be simulated, and a closed-loop controller implemented on a digital computer. The system will iclude a computer controlled muscle stimulator for m. soleus and m. tibialis anterior. Goniometers, inclinometers and force shoes will be evaluated as sources of the regulated variable. The long-term objective is the realization of an implantable closed-loop electrical stimulation orthosis to restore leg function in upper motor neuron paralysis. In paraplegia resulting from spinal cord injury, the natural neural control system is damaged. Paraplegics must presently rely on knee-ankle-foot orthoses for standing and forward progression. The expectation that FNS can further improve the ability of paraplegics to stand and make biped forward progression is predicted on the assumption that upright stability and postural sway can be controlled by means of FNS.
| Yarkony, G M; Jaeger, R J; Roth, E et al. (1990) Functional neuromuscular stimulation for standing after spinal cord injury. Arch Phys Med Rehabil 71:201-6 |
| Draganich, L F; Jaeger, R J; Kralj, A R (1989) Coactivation of the hamstrings and quadriceps during extension of the knee. J Bone Joint Surg Am 71:1075-81 |
| Jaeger, R J; Yarkony, G M; Smith, R M (1989) Standing the spinal cord injured patient by electrical stimulation: refinement of a protocol for clinical use. IEEE Trans Biomed Eng 36:720-8 |
| Bajzek, T J; Jaeger, R J (1987) Characterization and control of muscle response to electrical stimulation. Ann Biomed Eng 15:485-501 |
| Jaeger, R J (1986) Design and simulation of closed-loop electrical stimulation orthoses for restoration of quiet standing in paraplegia. J Biomech 19:825-35 |
| Jaeger, R; Smith, R; Scanu, M (1986) An application of a technique for the superimposition of computer graphics and video images in real time. Med Instrum 20:233-6 |
