Recruiting

SAF vs. Hydraulic Foot

Sponsor:

VA Office of Research and Development

Code:

NCT07266077

Conditions

Amputation

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Fillauer Slope Adaptive Foot

Fillauer Motion Foot SLX

Study Details

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.

Conditions

Amputation

Study ID

NCT07266077

Start date

Jul 1, 2026

Status verified date

Jul, 2026

Completion date

Aug 1, 2029

Anticipated

Primary completion date

Aug 1, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

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)

Study Design

Enrollment

30 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Supportive Care

Interventions and Outcome Measures

Arms

experimental: 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.

experimental: 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.

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.

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.

Primary outcome measure

  • PROMIS Ability to Participate in Social Roles and Activities (APSRA) [ Time Frame: Day 1 of the RCT, after each 4-week intervention in the RCT, and 13 weeks, 26 weeks, 39 weeks, and 52 weeks into the 1-year observational period of the study ]
  • PROMIS Satisfaction with Social Roles and Activities (SSRA) [ Time Frame: Day 1 of the RCT, after each 4-week intervention in the RCT, and 13 weeks, 26 weeks, 39 weeks, and 52 weeks into the 1-year observational period of the study ]

Central Contacts and Locations

Central contacts

Sara Koehler-McNicholas, PhD MS BS

(612) 467-4017sara.koehler@va.gov

Mary E Matsumoto, MD

(612) 725-2000mary.matsumoto@va.gov

Locations

Minneapolis VA Health Care System, Minneapolis, MN

Recruiting

Minneapolis, Minnesota, United States, 55417-2309

Contacts

Sara Koehler-McNicholas, PhD MS BS

(612) 467-4017sara.koehler@va.gov

Alexandria Lloyd, MS

(612) 467-4705alexandria.lloyd@va.gov

Principal Investigator:

Mary E Matsumoto, MD

More Information

Sponsor

VA Office of Research and Development

Last update posted

Jul 30, 2026

Last verified

Jul, 2026

Keywords

  • Artificial Limbs
  • Amputation
  • Leg Prosthesis
  • Ankle
  • Community Participation
  • Social Participation
  • Falls

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by VA Office of Research and Development on 2026-07-30.