Seated Ankle Robot for Foot Drop in Aging and Disabled Populations: A Demonstration Project

Many individuals with central nervous system (CNS) injuries (e.g., a stroke) or peripheral
nervous system (PNS) injuries (e.g., peroneal nerve injury, neuropathy, radiculopathy, and/or
musculoskeletal injury) that affect their ankle movement have residual impairments that
affect their walking and balance. These impairments include the disability "foot drop," which
increases the risk for falling.

This study will focus on PNS injuries that cause foot drop.

Current therapy to address foot drop is limited primarily to the use of ankle foot orthoses
(braces) that help keep the foot from hitting the ground to prevent falling. Also, some
individuals with foot drop use functional electrical stimulation to the leg nerve to lift the
foot. Regardless, none of these, or other existing, methods to address foot drop cures or
even improves significantly the underlying neurological deficit behind this disability.
Braces improve walking safety only while they are worn, and functional electrical stimulation
does not work when it is turned off, or when the nerve has been severely damaged. Thus, the
increased fall risk due to foot drop is generally considered life-long and incurable.

The investigators have developed a shoe-interfaced ankle robot with an adaptive control
system, to assist an individual with ankle movement only as needed. Data from the
investigators' previous studies on foot drop due to stroke show great promise for this ankle
robot as a new rehabilitation tool for invididuals with foot drop. The investigators would
like to utilize our findings from these stroke studies in learning how they can be used for
PNS-related foot drop.

Inclusion Criteria:

1. Men and women, aged 18 to 88 years

2. Chronic foot drop and ankle weakness in one leg from a peripheral nervous system
injury due to a neuromuscular or orthopedic injury

3. Ability to walk 10 meters and arise from a chair with no human assistance (but usage
of usual assistive device[s] is permitted)

Exclusion Criteria:

1. Medical history that would preclude participation in low-intensity seated
robotic-assisted rehabilitation

2. Current participation in orthopedic or rehabilitation medical programs

3. Active deep venous thrombosis

4. Distal paretic leg skin lesions, infections, or soft tissue inflammation