PROJECT SUMMARY
The parent project, “Toward Restoration of Normative Postural Control and Stability using Neural Control of
Powered Prosthetic Ankles”, R01HD110519, is developed to demonstrate that direct neural control of powered
prosthetic ankle can improve balance, postural stability, neuromuscular control, and coordination without
extensive cognitive processes, compared to daily prescribed passive devices for transtibial amputees.
Due to the amputation, lower limb amputees lack of perception on their prosthetic leg. Because deficits in
perception lead to delayed responses to postural sway, causing over-reliance on visual cues, impaired postural
control, and increased risk of falls, restoring reliable perception of the prosthetic limb is crucial for improving
resilience to disturbances, recovering from disturbances, and improving confidence while navigating dynamical
environments. Although previous studies suggest that improving lower limb perception through sensory
substitution (SS) can enhance postural stability in lower limb amputees, the link between perception and postural
stability is not well-established. One major challenge is that passive ankle joints cannot employ the same balance
strategies as natural ankles capable of producing torque. This forces amputees to adopt asymmetrical postural
control strategies that are hard to quantify. The parent project offers a unique opportunity by reinstating
symmetric ankle strategies and permits a systematical study to understand how lower limb perception affects
postural stability and neuromuscular coordination in postural control.
The objectives of this proposal include 1) evaluate the feasibility of enhancing postural control in LLA through
haptic sensory substitution when using a directly controlled powered prosthetic ankle, complementing the
objectives of the parent project focused on enabling symmetric ankle strategies for postural control; and 2)
providing training opportunities for Mr. Brendan Driscoll, a lower limb amputee himself, to advance his research
career.
This project has clear clinical significance since it addresses the clinical need for improved balance and postural
stability in lower limb amputees. Use of sensor substitution technology provides users with additional resources
to assist with balance stability and improve balance confidence, which, in turn, improves their community
participation and quality of life. At the same time, the proposed project is expected to contribute important
knowledge to the field of prosthesis technology, make scientific contributions to the fields of motor control and
learning, biomechanics, and cognitive-motor interaction, and benefit physical therapy and amputee rehabilitation.
