Authors: Daniel P. Ferris, Ph.D., Joseph M. Czerniecki, M.D., and Blake
Hannaford, Ph.D.; Electrical Engineering, Bioengineering, and
3Rehabilitation Medicine, University of Washington, Seattle, WA; Center
of Excellence for Limb Loss Prevention and Prosthetics Engineering, VA
Puget Sound Healthcare Center, Seattle, WA
How much adaptation and plasticity are possible in human locomotion muscle activity patterns? The answer to this question has profound implications toward locomotor rehabilitation after neurological or physical injury. If the gait pattern can be substantially modified, then rehabilitation should include locomotor specific training methods that can correct for gait pathologies. Increasing evidence suggests that locomotor training can greatly improve human walking ability after neurological injury. By providing partial body weight support and manual assistance during treadmill stepping, trainers can promote effective motor learning and help stroke and spinal cord injury patients improve their gait. However, manual assistance is labor-intensive and highly variable from trainer to trainer. A lightweight powered lower limb orthosis that can assist locomotor training would decrease labor requirements and provide more consistent therapy. Furthermore, a lightweight powered lower limb orthosis would provide the means to design very controlled motor learning studies to explore the limits of human locomotor adaptation. Just as robotic arms employing force fields on upper limb movements have greatly increased our knowledge of motor adaptation and learning, a powered lower limb orthosis could be used to study motor adaptation during locomotion. Thus, we are designing a lightweight lower limb orthosis that is powered by artificial pneumatic muscles (i.e., McKibben muscles) and uses proportional myoelectrical control. Supported by NIH AR08602 and U.S. Dept. of Veterans Affairs Center Grant #A0806C.