Automatic Activity-Dependent and Phase-Varying Prosthetic Foot Stiffness Modulation to Improve Balance Control in Individuals With Lower-Limb Amputations
Seattle Institute for Biomedical and Clinical Research
Summary
The goal of this clinical trial is to identify prosthesis stiffness that optimizes balance control in individuals with below knee amputations. The main question this clinical trial will answer is: • Is there an optimal stiffness that improves balance control for specific ambulatory activities and users? Participants will wear a novel prosthesis assembled with three prosthetic feet with a range of stiffness levels: each individual's clinically-prescribed foot stiffness and ± two stiffness categories. While wearing the study prostheses, participants will perform nine ambulatory activities of daily living (walking at different speeds, turning, ramp ascent/descent, while carrying a load, and while walking on uneven terrain).
Description
Individuals with lower limb amputations are at higher risk of falling compared to able-bodied and other clinical populations and are more likely to sustain life-altering injuries. The higher fall risk is primarily due to the loss of the muscles crossing the ankle, which are critical to maintaining balance control. Prosthetic devices are designed to provide appropriate stiffness for needed stability and support. While research has shown the optimal stiffness to maintain balance varies across ambulatory activities (e.g., straight walking versus turning), most clinically prescribed prosthetic dev…
Eligibility
- Age range
- 18–70 years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria: * Unilateral transtibial (below-knee) amputation * Been fit with a prosthesis and used it for at least 6 months * Wear the prosthesis for 4 or more hours on average per day * Be at least one-year post-amputation * Able to walk on a treadmill Exclusion Criteria: * Presence of disorder, pain, or injury other than amputation that interferes with gait * Current skin irritation or injury on residual limb * Use of an assistive device for walking (cane, walker, etc.)
Interventions
- DeviceAs-prescribed stiffness
A novel prosthesis that includes a low-profile prosthetic foot whose stiffness category is determined by the person's body weight and activity level (standard clinical practice).
- DeviceTwo categories stiffer than the as-prescribed stiffness
A novel prosthesis that includes a low-profile prosthetic foot whose stiffness category is two categories stiffer than the as-prescribed stiffness.
- DeviceTwo categories less stiff than the as-prescribed stiffness
A novel prosthesis that includes a low-profile prosthetic foot whose stiffness category is two categories less stiff than the as-prescribed stiffness.
Location
- VA Puget Sound Healthcare SystemSeattle, Washington