AmputationPhase 1TBALNCT07263945
Influence of Prosthetic Foot Stiffness on Transtibial Osseointegrated Bone-Anchored Limb Outcomes
A Phase 1 study testing As-prescribed prosthetic foot stiffness, A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic foot and A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic foot in people with Amputation and Transtibial Amputation - Unilateral, run by University of Colorado, Denver at 1 site in United States.
Trial summary
A clinical trial utilizing cross-over study design in which individuals with transtibial amputation using either a bone-anchored limb or standard socket prosthesis will perform activities of daily living with varying prosthetic foot stiffness categories to complete the following 4 Specific Aims: 1) Determine the… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Amputation, Transtibial Amputation - Unilateral, Bone Anchored Devices
- What is being tested?
- As-prescribed prosthetic foot stiffness, A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic foot and A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic foot
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 25 Nov 2025to 31 May 2030
- Phase
- Phase 1
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Unilateral transtibial amputation due to traumatic, congenital, or cancer-related causes
- > 12-months bone-anchored limb implantation surgery (Bone Anchored Limb group)
- > 12-months limb amputation (Socket Control group)
- Non-vascular amputation etiology
- Low profile prosthetic foot (nominal)
- Can walk unassisted for 5-minutes
- > 18 years old
Who cannot join
- Major amputation on contralateral limb
- Vascular amputation etiology
- Neurologic pathology that impairs coordination/balance
- Regular assistive device use required for community ambulation
- Inflammatory diseases or diabetes
- Pregnancy or breastfeeding
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Colorado, Anschutz Medical Campus
Aurora, Colorado, 80045-2559
Natalie Harpenau, M.S, (720) 772-6887, NATALIE.HARPENAU@CUANSCHUTZ.EDU
Brecca Gaffney, PhD, 303-315-7559, BRECCA.GAFFNEY@UCDENVER.EDU
About this study
A clinical trial utilizing cross-over study design in which individuals with transtibial amputation using either a bone-anchored limb or standard socket prosthesis will perform activities of daily living with varying prosthetic foot stiffness categories to complete the following 4 Specific Aims: 1) Determine the influence of prosthetic foot stiffness on dynamic bone-implant loading, 2) Determine how prosthetic foot stiffness influences function, pain, and multi-joint biomechanics outcomes, 3) Establish how prosthetic foot stiffness influences osseoperception and fall risk, and 4) Establish target ranges of optimal foot stiffness based on the sensitivity biomechanical outcomes to variability in foot stiffness.
Read the detailed description
This will be a clinical trial with two groups (individuals with a unilateral transtibial amputation using either an osseointegrated bone-anchored limb or socket prosthesis that will implement a cross-over design. The objective of this clinical trial is to determine how changes in prosthetic foot stiffness influence clinical and biomechanical outcomes in patients with transtibial osseointegrated bone-anchored limbs compared to patients with transtibial amputation using a standard socket-suspended prosthesis. Although proper loading between the bone and implant is pivotal to promote and maintain osseointegration, which is required for physiological loading and thus positive outcomes, evidence surrounding the role of how prosthetic componentry influences force transmission and functional outcomes in this population currently does not exist. The findings of this clinical trial will address a critical knowledge gap pertaining to the role of componentry on multi-loading domain outcomes. Outcomes will be assessed in each participant in the same three conditions: one with their clinical prescribed prosthetic foot, one with a soft prosthetic foot (-2 stiffness categories less than prescribed), and one with a stiff prosthetic foot (+2 stiffness categories more than prescribed). This data will be used to test/develop the following aims: 1) Does foot stiffness change loading between the bone and implant during activities of daily living? 2) Does foot stiffness influence measures of function, pain, and biomechanics in patients with transtibial osseointegrated bone-anchored limbs differently than a socket prosthesis? 3) Does foot stiffness influence sensitivity, balance, and fall risk in patients using an osseointegrated bone-anchored limb different than a socket prosthesis? and 4) (exploratory) develop an optimization platform using computer models to determine the optimal foot stiffness that maximizes joint loading symmetry and minimizes metabolic cost.
- Being tested
- As-prescribed prosthetic foot stiffness, A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic foot, A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic foot
- Keywords
- amputation, bone anchored limb, osseointegration, transtibial amputation, below knee amputation, prosthetics
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
As-prescribed prosthetic foot stiffnessDevice
Each participant will complete a motion capture collection, tests of physical function, and sensory tests in their currently prescribed prosthetic foot.
A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic footDevice
Each participant will complete a motion capture collection, tests of physical function, and sensory tests in a prosthetic foot that is two categories stiffer than their currently prescribed prosthetic foot.
A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic footDevice
Each participant will complete a motion capture collection, tests of physical function, and sensory tests in a prosthetic foot that is two categories softer than their currently prescribed prosthetic foot.
| Study group | Role | What they receive |
|---|---|---|
| Two prosthetic foot stiffness categories stiffer than the as-prescribed prosthetic foot stiffness | Active comparator | A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic foot. The prosthetic foot type, including the manufacturer and length, will remain the same as the nominal (as-currently prescribed) foot. Receives: Device: A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic foot |
| Two prosthetic foot stiffness categories softer than the as-prescribed prosthetic foot stiffness | Active comparator | A prosthetic foot that is two prosthetic foot stiffness categories softer than the stiffness of the as-prescribed prosthetic foot. The prosthetic foot type, including the manufacturer and length, will remain the same as the nominal foot. Receives: Device: A prosthetic foot that is two prosthetic foot stiffness categories stiffer than the stiffness of the as-prescribed prosthetic foot |
| As-prescribed prosthetic foot stiffness | Active comparator | The prosthetic foot that is currently prescribed and used by each participant daily. Receives: Device: As-prescribed prosthetic foot stiffness |
What is being measured
The primary outcome is the main question the study is designed to answer.
Bone-Implant Stress/Strain Impulse during Decline Walking (internal)
Stress/strain impulse at the bone-implant interface (area under time series curve) will be calculated during the stance period of the decline walk (-5 degrees). Subject-specific finite element models will be developed for each bone-anchored limb participant to calculate this outcome. This will be done by including each participant's movement patterns, muscle forces, joint forces, bone geometry and bone health. Movement patterns, muscle forces, and joint loading will be calculated from musculoskeletal modeling using whole-body motion data collected from 70 wearable reflective markers (Vicon, Centennial, CO), ground reaction forces simultaneously collected from an instrumented treadmill (Bertec, Columbus, OH). Bone geometry and healthy will be determined from quantitative computed tomography bone scans.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Secondary outcomes (14)
Bone-Implant Dynamic Stress/Strain Impulse (internal)
Stress/strain impulse at the bone-implant interface (area under time series curve) will be calculated for each bone-anchored limb participant using motion and force data collected during the stance period of treadmill walking at level and incline (+5 degree) angles.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Bone Dynamic Stress/Strain Impulse (internal)
Stress/strain impulse for the amputated tibia bone (area under time series curve) will be calculated for each bone-anchored limb participant using motion and force data collected during the stance period of treadmill walking at level, incline (+5 degree), and decline (-5 degree) angles.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Implant Dynamic Stress/Strain Impulse (internal)
Stress impulse for the prosthesis implant (area under time series curve) will be calculated for each bone-anchored limb participant using motion and force data collected during the stance period of treadmill walking at level, incline (+5 degree), and decline (-5 degree) angles.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Prosthesis Force Impulse (external abutment)
Force impulse in the vertical direction (area under the time series curve) will be calculated for all study participants using motion and force data collected from the triaxial load sensor in the prosthesis (iPECSTM) during the stance period of treadmill walking at level, incline (+5 degree), and decline (-5 degree) angles.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Sensory Threshold
With each foot (stiff, nominal (as-prescribed), soft), participants will stand on a platform with the prosthetic equivalent of the head of the third metatarsal in contact with an extension pin delivering a vibration. While wearing noise-reducing headphones, three different vibration frequencies will be tested in a randomized order: 8, 32, and 125 Hz. At each frequency, custom software will increase and decrease the vibrational amplitude at a rate of 0.2 dB/s. Using an integrated push button, the participant will indicate when sensation is felt (during increasing amplitude) or when sensation is lost (during decreasing amplitude), which will be the sensory threshold.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Postural Sway
Postural sway will be quantified during quiet standing with eyes open and eyes closed condition. Using the center of pressure measured from the force platform under both feet, path length and 95% confidence ellipse area will be calculated.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Reactive Postural Control Time
Reaction times during stepping responses to rapid treadmill belt perturbations will be measured using a force-instrumented treadmill (Bertec, Columbus, OH, USA).
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Whole-Body Angular Momentum
Peak-to-peak whole-body angular momentum will be calculated as a measure of dynamic balance during each dynamic functional activity (level/incline/decline walking and stair ascent/descent) and treadmill perturbation.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Self-Selected Gait Speed
Gait velocity will be calculated using the time it takes each participant to walk 5-meters at their preferred, self-selected pace, averaged over three trials.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
L-Test Time
The L-test will be quantified as the time it takes to stand up from a chair, walk 3-meters, complete a 90° left turn, walk 7-meters, completed a 180° turn, walk back on the same path, turn, and sit down.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Acceptability of Intervention Measure
The Acceptability of Intervention Measure is a 4-item, Likert-scale (5 point) self-report questionnaire assessing participant acceptability of the intervention (prosthetic foot type). Final scores range from 1 to 5 points, as the mean of the four items, with higher scores indicating greater acceptability.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Prosthetic Limb Users Survey of Mobility
The Prosthetic Limb Users Survey of Mobility is a 12-item, Likert scale (5 point) self-report questionnaire assessing participant mobility when using a prosthesis. Final scores range from 12 to 60 points with higher scores indicating greater mobility.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Activities-Specific Balance Confidence Scale
The Activities-Specific Balance Confidence Scale is a 16-item, 0-100 scale, self-reported questionnaire assessing participant balance confidence. Final scores range from 0% (no confidence in balance) to 100% (complete confidence in balance).
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Joint Reaction Force
Bilateral hip and knee joint reaction forces (normalized to body weight) will be calculated during treadmill walking using a combination of motion-capture data and subject-specific musculoskeletal models.
Measured: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Dec 2025
- Study start25 Nov 2025
- Primary completion31 May 2030 (estimated)
- Study completion31 May 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AmputationStudies of the same condition, open and under way.
- More trials run by University of Colorado, DenverThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Denver
- Sponsor type
- University, hospital or other
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07263945
- Sponsor's protocol ID
- 25-0854
- Other IDs
- 1R01HD119003-01
- Acronym
- TBAL
- Status last verified
- Oct 2026
- First submitted
- 22 Oct 2025
- Last updated
- 19 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The investigators will publish the trial results data on the ClinicalTrials.gov website, on which the clinical trial will be registered. Sharing of data will include the potential of sharing raw data generated from all clinical assessments under a data-sharing agreement.