Influence Of A Slope Adaptive Foot On Participation Of Veterans With Lower-Limb Amputations

NCT ID: NCT07266077

Last Updated: 2025-12-05

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-04-01
• Study Completion Date: 2029-04-01

Brief Summary

Veterans with below-knee amputations are limited by prosthetic feet that cannot adapt to sloped and uneven terrain. This limitation results in reduced mobility, reduced balance confidence, and a higher risk of falls among some individuals who use below-knee prostheses, which have been shown to negatively impact participation in daily and recreational activities. The investigative group has designed a novel Slope Adaptive Foot (SAF) that is mechanically passive, capable of slope adaption on every step of walking, and maintains high levels of energy storage and return. Pilot testing of the SAF with Veterans has generated excellent results to date, with comments suggesting potential improvements in participation. This study will evaluate the extent to which participation and fall-related health outcomes are influenced by using the SAF versus a typical hydraulic foot in a cross-over randomized controlled trial. Using mixed-methods, the investigators will also collect long-term data of Veterans using their preferred foot to inform the development of evidence-based education materials for use in clinical decision making.

Detailed Description

Background and Relevance to VA - Over 90% of Veterans who use a below-knee prosthesis in the community are prescribed an energy storage and return (ESAR) foot. ESAR feet are designed to assist with forward propulsion during walking, which many users find helpful for certain activities. However, ESAR feet lack ankle articulation, making it difficult to walk on non-level surfaces. To overcome this limitation, typical hydraulic feet incorporate damped ankle motion to accommodate walking on uneven terrain. While potentially improving aspects of participation and fall-related health, typical hydraulic feet have reduced energy storage and return compared to ESAR feet.

To combine the benefits of ESAR and typical hydraulic feet, the Minneapolis VA, in collaboration with Fillauer Motion Control, Inc., has developed a novel hydraulic Slope Adaptive Foot (SAF). During pilot testing, most Veterans preferred the SAF over their prescribed ESAR foot and reported improvements in participation. Further research is needed to evaluate the impact of different prosthetic feet on participation and fall-related health in order to identify which patients are best suited for an ESAR foot, a typical hydraulic foot, or the SAF.

Innovation and Impact - The long-term goal of this project is to inform prescription of hydraulic feet for Veterans living with lower-limb amputation to optimize their participation in important life roles and activities. Results of this study will help to develop evidence-based provider training and patient education materials to assist with precision rehabilitation and a patient-centered care approach to prescribing hydraulic prosthetic feet.

Aim 1 - Evaluate the influence of different prosthetic foot-related factors on participation. PROMIS Ability to Participate in Social Roles and Activities (APSRA) and PROMIS Satisfaction with Social Roles and Activities (SSRA) will be administered during a cross-over randomized control trial (RCT). This aim will test the hypothesis that using the SAF will be associated with greater PROMIS-APSRA and/or PROMIS-SSRA scores relative to a typical hydraulic foot and that using either hydraulic foot will be associated with greater PROMIS-APSRA and/or PROMIS-SSRA scores compared to the ESAR foot.

Aim 2 - Characterize the lived experiences of Veterans using their preferred prosthetic foot to inform clinical decision making. Mixed-methods will be used to explore how participation in social roles and activities is influenced by hydraulic and ESAR feet. Gaining a deeper understanding of Veterans' experiences across a range of situations and environments will inform the development of evidence-based education materials.

Exploratory Aim - Evaluate the influence of different prosthetic foot-related factors on fall-related health outcomes. The Prosthetic Limb Users Survey of Fall-Related Health (PLUS-FRH), which includes four distinct and important domains, will be administered during a cross-over RCT. This aim will test the hypothesis that using the SAF will be associated with improved fall-related health outcomes relative to a typical hydraulic foot and that using either hydraulic foot will be associated with improved fall-related health outcomes compared to the ESAR foot.

Methodology - To address these aims, this study will 1) conduct a cross-over RCT of the SAF versus a typical hydraulic foot (Motion Foot SLX, Fillauer) among 30 Veterans with a below-knee amputation who use an ESAR foot and have no prior experience with a hydraulic foot, and 2) conduct a one-year observational study in which Veterans use their preferred prosthetic foot. Participants will complete quantitative (PROMIS-APSRA, PROMIS-SSRA, PLUS-FRH) and qualitative (semi-structured interviews) assessments at baseline and after each period of the cross-over RCT and quarterly during the one-year observational study. A participatory method will be used in which Veterans will be asked to share photos with a short narrative to portray their experiences with their preferred prosthetic foot to prompt discussion during the quarterly interviews of the one-year observational study.

Participating Sites - Minneapolis VA Health Care System (data collection site) and the University of Washington.

Duration of Participant Intake (Study Duration) - This project is projected to occur over four years. The project will begin with a 3-month start-up period and recruitment will continue for 18 months following start-up. Data collection will conclude with 9 months remaining in the study timeline, which will be used for data analysis, dissemination, development of implementation materials, and study closure.

Path to Implementation - Data gathered from this study will be used to draft evidence-based education materials for providers and Veterans. These materials, which will provide pertinent and useful information about foot options (ESAR, SLX, SAF) for prosthetic prescription, will be used in a future implementation study.

Conditions

Amputation

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: NONE

Study Groups

SAF-SLX

Participants in this arm will start the cross-over randomized controlled trial with the SAF. After a four-week take-home period with the SAF, participants will return to their usual prosthetic foot for a four-week washout period. They will then be fit with the SLX for a four-week take-home period.

Group Type: EXPERIMENTAL

Fillauer Slope Adaptive Foot

Intervention Type: DEVICE

The SAF uses an articulated ankle and damped plantarflexion to accommodate slopes and uneven terrain. It locks when the forefoot reaches the ground at the beginning of stance phase, which allows the SAF to re-align, or adapt, to the walking surface. After the SAF locks, the laminated foot plate can deflect and store energy as dorsiflexion occurs, returning that energy to the user in late stance for forward propulsion. Finally, at the end of stance phase, when the toe leaves the ground, the SAF unlocks and actively dorsiflexes the ankle to increase toe clearance during swing.

Fillauer Motion Foot SLX

Intervention Type: DEVICE

The SLX is an articulated, hydraulic ankle that provides passive ankle motion through damped plantarflexion and dorsiflexion to facilitate slope accommodation.

SLX-SAF

Participants in this arm will start the cross-over randomized controlled trial with the SLX. After a four-week take-home period with the SLX, participants will return to their usual prosthetic foot for a four-week washout period. They will then be fit with the SAF for a four-week take-home period.

Group Type: EXPERIMENTAL

Fillauer Slope Adaptive Foot

Intervention Type: DEVICE

The SAF uses an articulated ankle and damped plantarflexion to accommodate slopes and uneven terrain. It locks when the forefoot reaches the ground at the beginning of stance phase, which allows the SAF to re-align, or adapt, to the walking surface. After the SAF locks, the laminated foot plate can deflect and store energy as dorsiflexion occurs, returning that energy to the user in late stance for forward propulsion. Finally, at the end of stance phase, when the toe leaves the ground, the SAF unlocks and actively dorsiflexes the ankle to increase toe clearance during swing.

Fillauer Motion Foot SLX

Intervention Type: DEVICE

The SLX is an articulated, hydraulic ankle that provides passive ankle motion through damped plantarflexion and dorsiflexion to facilitate slope accommodation.

Interventions

Fillauer Slope Adaptive Foot

The SAF uses an articulated ankle and damped plantarflexion to accommodate slopes and uneven terrain. It locks when the forefoot reaches the ground at the beginning of stance phase, which allows the SAF to re-align, or adapt, to the walking surface. After the SAF locks, the laminated foot plate can deflect and store energy as dorsiflexion occurs, returning that energy to the user in late stance for forward propulsion. Finally, at the end of stance phase, when the toe leaves the ground, the SAF unlocks and actively dorsiflexes the ankle to increase toe clearance during swing.

Intervention Type: DEVICE

Fillauer Motion Foot SLX

The SLX is an articulated, hydraulic ankle that provides passive ankle motion through damped plantarflexion and dorsiflexion to facilitate slope accommodation.

Intervention Type: DEVICE

Other Intervention Names

SAF; SLX

Eligibility Criteria

Inclusion Criteria

• US military Veterans willing to travel to the Minneapolis VA Health Care System
• Unilateral, below-knee amputation
• Use of a definitive prosthesis for at least 12 months (limb volume has stabilized and has accommodated to prosthesis use post-amputation)
• Medicare Functional Classification Level K3 ambulator (unlimited community ambulator)
• Well-fitting and well-aligned prosthesis
• Uses a prescribed energy storage and return foot (ESAR)
• Blessed Orientation-Memory-Concentration (Short Blessed) test score between 0-6 (no cognitive impairment)
• Access to computer, tablet, or smartphone and internet for video conferencing and REDCap data collection

Exclusion Criteria

• Residual-limb skin problems
• Not a regular prosthesis user
• Mass over 125 kg (275 lbs)
• Residual limb too long to accommodate the study feet (104 mm of build height)
• Has used a hydraulic foot previously as part of clinical care or a research study
• Documented major neurocognitive disorder (i.e., dementia) with evidence of impact on activities of daily living and/or instrumental activities of daily living
• Baseline PROMIS-APSRA or PROMIS-SSRA scores at the maximum levels (no room for improvement on primary outcomes)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 89 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Washington

OTHER

Sponsor Role: collaborator

VA Office of Research and Development

FED

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Sara Koehler-McNicholas, PhD MS BS

Role: PRINCIPAL_INVESTIGATOR

Minneapolis VA Health Care System, Minneapolis, MN

Mary E Matsumoto, MD

Role: PRINCIPAL_INVESTIGATOR

Minneapolis VA Health Care System, Minneapolis, MN

Locations

Minneapolis VA Health Care System, Minneapolis, MN

Minneapolis, Minnesota, United States

Countries

United States

Central Contacts

Sara Koehler-McNicholas, PhD MS BS

Role: CONTACT

sara.koehler@va.gov

(612) 467-4017

Mary E Matsumoto, MD

Role: CONTACT

mary.matsumoto@va.gov

(612) 725-2000

Facility Contacts

Sara Koehler-McNicholas, PhD MS BS

Role: primary

sara.koehler@va.gov

612-467-4017

Alexandria Lloyd, MS

Role: backup

alexandria.lloyd@va.gov

(612) 467-4705

Other Identifiers

RRD4-004-24W

Identifier Type: -

Identifier Source: org_study_id