AmputationNCT07159490
Lower Limb Prostheses for Individuals Who Carry Infants, Toddlers, and Other Loads
A study testing Standard-of-care prosthetic foot, Standard-of-care prosthetic foot with heel-stiffening wedge and Standard-of-care prosthetic foot of one category greater stiffness in people with Amputation and Prosthesis User, run by VA Puget Sound Health Care System at 1 site in United States.
Trial summary
The aim of this research is to identify the prosthetic foot that results in improved walking performance when individuals with lower limb amputation carry infants, toddlers, or other loads. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Amputation, Prosthesis User
- What is being tested?
- Standard-of-care prosthetic foot, Standard-of-care prosthetic foot with heel-stiffening wedge and Standard-of-care prosthetic foot of one category greater stiffness
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 13 participants
- Where
- 1 siteUnited States
- Study dates
- 3 Dec 2020to 1 Oct 2025
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Unilateral transtibial amputee
- Have been fitted with and used a prosthesis for at least six months
- Do not use heel stiffening wedges or bumpers in their as-prescribed prosthesis
- Wear their prosthesis for at least four hours per day
- Are moderately active by self-report
- Can be fitted with the study prostheses (prosthetic foot size, stiffness category and build heights)
Who cannot join
- Do not have a proper fit and suspension and one cannot be achieved with clinical resources
- Presence of disorder, pain, or injury other than amputation that interferes with gait
Trial locations and contacts
1 site in 1 country.
United States1 site
VA Puget Sound Health Care System Seattle Division
Seattle, Washington, 98108
About this study
The aim of this research is to identify the prosthetic foot that results in improved walking performance when individuals with lower limb amputation carry infants, toddlers, or other loads.
Read the detailed description
The natural lower limbs provide important biomechanical functions such as body weight support, forward propulsion, and balance control during ambulation. When the loads borne by the lower limbs change, lower limb muscle activation responds accordingly to enable seamless continuation of biomechanical function. These loads can change suddenly, such as when carrying an infant, toddler, or other load like a heavy backpack. For individuals with a lower limb amputation, these sudden changes to weight-bearing loads can be problematic because they can negatively impact walking performance. One reason walking performance may suffer is that the properties of most prosthetic limbs, such as their stiffness, are constant and do not change to suit varying load conditions. Another reason is that the most widely prescribed prosthetic feet do not have motors, sensors, or brain-like controllers that act to replace the neuromuscular system of the amputated limb. Regardless of the reason, no evidence exists to guide prescription practice for veterans who walk with a prosthesis and experience sudden load changes.
The aim of this research is to identify the prosthetic foot that results in improved walking performance when individuals with lower limb amputation carry infants, toddlers, or other loads. The investigators will conduct a human subject experiment with help of twenty individuals with below-knee amputations. Study participants will walk on a treadmill with no added load and four added load conditions using a weighted pack (13.6 kg or ~30 lbs) to simulate an infant, toddler, or other load. The four conditions include the pack strapped to their front, their back, and carried with their arms on the intact limb side and the prosthetic limb side. Each participant will wear a usual prosthetic foot, this same foot with a heel-stiffening wedge, the same prosthetic foot but one category stiffness higher, a new-to-market dual keel prosthetic foot intended for load carrying situations, and a powered ankle foot prosthesis. The results from these experiments will aid clinicians in specifying the best prosthesis for individuals with lower limb amputations who frequently carry infants, toddlers, or other loads.
For individuals who wear a lower limb prosthesis while carrying infants, toddlers, or other loads, this research will provide evidence to support prosthesis prescription practice that reduces undesirable compensatory responses to load carriage. The objective is to help clinicians select among currently available solutions to enable individuals with lower limb loss to achieve their life and work goals.
- Conditions
- Amputation, Prosthesis User
- Being tested
- Standard-of-care prosthetic foot, Standard-of-care prosthetic foot with heel-stiffening wedge, Standard-of-care prosthetic foot of one category greater stiffness, Dual keel prosthetic foot, Powered ankle-foot
- Keywords
- Lower limb prosthesis, Transtibial amputation, Below knee amputation, Biomechanics
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Standard-of-care prosthetic footDevice
Also called Sierra, Freedom Innovations
Widely prescribed prosthetic foot of stiffness category appropriate to the participant's body weight and activity level.
Standard-of-care prosthetic foot with heel-stiffening wedgeDevice
Also called Sierra, Freedom Innovations
Widely prescribed prosthetic foot with a wedge inserted between the heel and foot keels intended to stiffen the behavior of the heel.
Standard-of-care prosthetic foot of one category greater stiffnessDevice
Also called Sierra, Freedom Innovations
Widely prescribed prosthetic foot of one stiffness category greater than usually prescribed based on the participant's body weight and activity level.
Dual keel prosthetic footDevice
Also called Thrive, Freedom Innovations
A prosthetic foot with two forefoot keels intended for load carriage applications.
Powered ankle-footDevice
Also called Empower, Otto Bock
A powered prosthetic ankle-foot.
| Study group | Role | What they receive |
|---|---|---|
| No added load | Experimental | Study participants will walk with no added load. Receives: Device: Standard-of-care prosthetic foot; Device: Standard-of-care prosthetic foot with heel-stiffening wedge; Device: Standard-of-care prosthetic foot of one category greater stiffness; Device: Dual keel prosthetic foot; Device: Powered ankle-foot |
| Anterior added load | Experimental | Study participants will walk with 13.6 kg (30 lbs) of added load on their anterior side. Receives: Device: Standard-of-care prosthetic foot; Device: Standard-of-care prosthetic foot with heel-stiffening wedge; Device: Standard-of-care prosthetic foot of one category greater stiffness; Device: Dual keel prosthetic foot; Device: Powered ankle-foot |
| Posterior added load | Experimental | Study participants will walk with 13.6 kg (30 lbs) of added load on their posterior side. Receives: Device: Standard-of-care prosthetic foot; Device: Standard-of-care prosthetic foot with heel-stiffening wedge; Device: Standard-of-care prosthetic foot of one category greater stiffness; Device: Dual keel prosthetic foot; Device: Powered ankle-foot |
| Intact-side added load | Experimental | Study participants will walk with 13.6 kg (30 lbs) of added load on their intact side. Receives: Device: Standard-of-care prosthetic foot; Device: Standard-of-care prosthetic foot with heel-stiffening wedge; Device: Standard-of-care prosthetic foot of one category greater stiffness; Device: Dual keel prosthetic foot; Device: Powered ankle-foot |
| Prosthetic-side added load | Experimental | Study participants will walk with 13.6 kg (30 lbs) of added load on their prosthetic side. Receives: Device: Standard-of-care prosthetic foot; Device: Standard-of-care prosthetic foot with heel-stiffening wedge; Device: Standard-of-care prosthetic foot of one category greater stiffness; Device: Dual keel prosthetic foot; Device: Powered ankle-foot |
What is being measured
The primary outcome is the main question the study is designed to answer.
Vertical Ground Reaction Force Impulse (Normalized)
A measure of body support. Normalized by body mass, including the mass of the load when applicable.
Measured: During study visit (approximately 3 hours)
Anterior Ground Reaction Force Impulse (Normalized)
A measure of body forward propulsion. Normalized by body mass, including the mass of the load when applicable.
Measured: During study visit (approximately 3 hours)
Peak-to-peak Range of Sagittal Plane Whole-body Angular Momentum (Normalized)
A measure of balance control primarily for anterior and posterior added load conditions. Normalized by body mass (kg) including the mass of the load when applicable, body height (m), and [gravity*body height]^0.5 (m/s) resulting in a unitless number.
Measured: During study visit (approximately 3 hours)
Peak-to-peak Range of Coronal Plane Whole-body Angular Momentum (Normalized)
A measure of balance control primarily for intact-side added load conditions. Normalized by body mass (kg) including the mass of the load when applicable, body height (m), and [gravity*body height]^0.5 (m/s) resulting in a unitless number.
Measured: During study visit (approximately 3 hours)
Net Positive Ankle Joint Mechanical Work Over the Prosthetic Limb Gait Cycle (Normalized)
Positive ankle joint mechanical work over the prosthetic limb gait cycle is a measure of propulsion capability. A prosthetic foot with greater propulsion capability may enhance gait efficiency during everyday ambulation. Normalized to body mass and the added load mass when applicable.
Measured: During study visit (approximately 3 hours)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Sep 2025
- Study start3 Dec 2020
- Primary completion1 Oct 2025
- Study completion1 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for AmputationStudies of the same condition, open and under way.
- 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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Model description
- This study will employ a within-subject experimental design. Each participant will wear, in randomized order, a standard-of-care prosthetic foot, this same prosthetic foot with a heel-stiffening wedge, this same prosthetic foot but one category stiffer, a dual keel prosthetic foot intended for load carriage applications, and a powered ankle-foot purported to adapt to changing loads. All study prostheses are commercially available. Each participant, wearing each of the study prostheses, will walk overground with no added load and four added load conditions of 13.6 kg: anterior, posterior, intact-side carry, and prosthetic-side carry. The load condition will be presented in block randomized order.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 13 participants (actual)
Sponsor and investigators
- Lead sponsor
- VA Puget Sound Health Care System
- Sponsor type
- US federal agency
- Responsible party
- Principal investigator, Glenn K. Klute, PhD, VA Puget Sound Health Care System
- Investigators
- Glenn Klute, PhD, Principal investigator, VA Puget Sound Care System
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07159490
- Sponsor's protocol ID
- 1588093
- Status last verified
- Jan 2026
- First submitted
- 1 Jun 2022
- Last updated
- 12 Feb 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: A de-identified, anonymized dataset in machine-readable format will be created and shared for all individual participant data (IPD) that underlie results in a publication. The investigators will follow 164.514(a) of the HIPAA Privacy Rule for de-identification of IPD.
Study at a glance
From the registry record, last updated by the sponsor on 12 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Lower Limb Prostheses for Individuals Who Carry Infants, Toddlers, and Other Loads
- ClinicalTrials.gov ID
- NCT07159490
- Acronym / sponsor ID
- 1588093
- Conditions
- Amputation, Prosthesis User
- Keywords
- Lower limb prosthesis, Transtibial amputation, Below knee amputation, Biomechanics
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 13 participants (actual)
- Lead sponsor
- VA Puget Sound Health Care SystemUS federal agency
- Study start
- 3 Dec 2020 (actual)
- Primary completion
- 1 Oct 2025 (actual)
- Study completion
- 1 Oct 2025 (actual)
- First posted
- 8 Sep 2025 (actual)
- Results
- Posted 12 Feb 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of this research is to identify the prosthetic foot that results in improved walking performance when individuals with lower limb amputation carry infants, toddlers, or other loads.
Detailed description
The natural lower limbs provide important biomechanical functions such as body weight support, forward propulsion, and balance control during ambulation. When the loads borne by the lower limbs change, lower limb muscle activation responds accordingly to enable seamless continuation of biomechanical function. These loads can change suddenly, such as when carrying an infant, toddler, or other load like a heavy backpack. For individuals with a lower limb amputation, these sudden changes to weight-bearing loads can be problematic because they can negatively impact walking performance. One reason walking performance may suffer is that the properties of most prosthetic limbs, such as their stiffness, are constant and do not change to suit varying load conditions. Another reason is that the most widely prescribed prosthetic feet do not have motors, sensors, or brain-like controllers that act to replace the neuromuscular system of the amputated limb. Regardless of the reason, no evidence exists to guide prescription practice for veterans who walk with a prosthesis and experience sudden load changes.
The aim of this research is to identify the prosthetic foot that results in improved walking performance when individuals with lower limb amputation carry infants, toddlers, or other loads. The investigators will conduct a human subject experiment with help of twenty individuals with below-knee amputations. Study participants will walk on a treadmill with no added load and four added load conditions using a weighted pack (13.6 kg or ~30 lbs) to simulate an infant, toddler, or other load. The four conditions include the pack strapped to their front, their back, and carried with their arms on the intact limb side and the prosthetic limb side. Each participant will wear a usual prosthetic foot, this same foot with a heel-stiffening wedge, the same prosthetic foot but one category stiffness higher, a new-to-market dual keel prosthetic foot intended for load carrying situations, and a powered ankle foot prosthesis. The results from these experiments will aid clinicians in specifying the best prosthesis for individuals with lower limb amputations who frequently carry infants, toddlers, or other loads.
For individuals who wear a lower limb prosthesis while carrying infants, toddlers, or other loads, this research will provide evidence to support prosthesis prescription practice that reduces undesirable compensatory responses to load carriage. The objective is to help clinicians select among currently available solutions to enable individuals with lower limb loss to achieve their life and work goals.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Single blind (participant)
- Number of arms
- 5
- Model description
- This study will employ a within-subject experimental design. Each participant will wear, in randomized order, a standard-of-care prosthetic foot, this same prosthetic foot with a heel-stiffening wedge, this same prosthetic foot but one category stiffer, a dual keel prosthetic foot intended for load carriage applications, and a powered ankle-foot purported to adapt to changing loads. All study prostheses are commercially available. Each participant, wearing each of the study prostheses, will walk overground with no added load and four added load conditions of 13.6 kg: anterior, posterior, intact-side carry, and prosthetic-side carry. The load condition will be presented in block randomized order.
| Arm | Type | Receives |
|---|---|---|
| No added load | Experimental | Device: Standard-of-care prosthetic foot, Device: Standard-of-care prosthetic foot with heel-stiffening wedge, Device: Standard-of-care prosthetic foot of one category greater stiffness, Device: Dual keel prosthetic foot, Device: Powered ankle-footStudy participants will walk with no added load. |
| Anterior added load | Experimental | Device: Standard-of-care prosthetic foot, Device: Standard-of-care prosthetic foot with heel-stiffening wedge, Device: Standard-of-care prosthetic foot of one category greater stiffness, Device: Dual keel prosthetic foot, Device: Powered ankle-footStudy participants will walk with 13.6 kg (30 lbs) of added load on their anterior side. |
| Posterior added load | Experimental | Device: Standard-of-care prosthetic foot, Device: Standard-of-care prosthetic foot with heel-stiffening wedge, Device: Standard-of-care prosthetic foot of one category greater stiffness, Device: Dual keel prosthetic foot, Device: Powered ankle-footStudy participants will walk with 13.6 kg (30 lbs) of added load on their posterior side. |
| Intact-side added load | Experimental | Device: Standard-of-care prosthetic foot, Device: Standard-of-care prosthetic foot with heel-stiffening wedge, Device: Standard-of-care prosthetic foot of one category greater stiffness, Device: Dual keel prosthetic foot, Device: Powered ankle-footStudy participants will walk with 13.6 kg (30 lbs) of added load on their intact side. |
| Prosthetic-side added load | Experimental | Device: Standard-of-care prosthetic foot, Device: Standard-of-care prosthetic foot with heel-stiffening wedge, Device: Standard-of-care prosthetic foot of one category greater stiffness, Device: Dual keel prosthetic foot, Device: Powered ankle-footStudy participants will walk with 13.6 kg (30 lbs) of added load on their prosthetic side. |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Unilateral transtibial amputee
- Have been fitted with and used a prosthesis for at least six months
- Do not use heel stiffening wedges or bumpers in their as-prescribed prosthesis
- Wear their prosthesis for at least four hours per day
- Are moderately active by self-report
Key exclusion criteria (2 listed)
- Do not have a proper fit and suspension and one cannot be achieved with clinical resources
- Presence of disorder, pain, or injury other than amputation that interferes with gait
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Standard-of-care prosthetic footAlso: Sierra, Freedom InnovationsWidely prescribed prosthetic foot of stiffness category appropriate to the participant's body weight and activity level. | Device | Anterior added load, Intact-side added load, No added load, Posterior added load, Prosthetic-side added load |
| Standard-of-care prosthetic foot with heel-stiffening wedgeAlso: Sierra, Freedom InnovationsWidely prescribed prosthetic foot with a wedge inserted between the heel and foot keels intended to stiffen the behavior of the heel. | Device | Anterior added load, Intact-side added load, No added load, Posterior added load, Prosthetic-side added load |
| Standard-of-care prosthetic foot of one category greater stiffnessAlso: Sierra, Freedom InnovationsWidely prescribed prosthetic foot of one stiffness category greater than usually prescribed based on the participant's body weight and activity level. | Device | Anterior added load, Intact-side added load, No added load, Posterior added load, Prosthetic-side added load |
| Dual keel prosthetic footAlso: Thrive, Freedom InnovationsA prosthetic foot with two forefoot keels intended for load carriage applications. | Device | Anterior added load, Intact-side added load, No added load, Posterior added load, Prosthetic-side added load |
| Powered ankle-footAlso: Empower, Otto BockA powered prosthetic ankle-foot. | Device | Anterior added load, Intact-side added load, No added load, Posterior added load, Prosthetic-side added load |
Primary outcome
Vertical Ground Reaction Force Impulse (Normalized)
Time frame: During study visit (approximately 3 hours)
A measure of body support. Normalized by body mass, including the mass of the load when applicable.
Anterior Ground Reaction Force Impulse (Normalized)
Time frame: During study visit (approximately 3 hours)
A measure of body forward propulsion. Normalized by body mass, including the mass of the load when applicable.
Peak-to-peak Range of Sagittal Plane Whole-body Angular Momentum (Normalized)
Time frame: During study visit (approximately 3 hours)
A measure of balance control primarily for anterior and posterior added load conditions. Normalized by body mass (kg) including the mass of the load when applicable, body height (m), and [gravity*body height]^0.5 (m/s) resulting in a unitless number.
Peak-to-peak Range of Coronal Plane Whole-body Angular Momentum (Normalized)
Time frame: During study visit (approximately 3 hours)
A measure of balance control primarily for intact-side added load conditions. Normalized by body mass (kg) including the mass of the load when applicable, body height (m), and [gravity*body height]^0.5 (m/s) resulting in a unitless number.
Net Positive Ankle Joint Mechanical Work Over the Prosthetic Limb Gait Cycle (Normalized)
Time frame: During study visit (approximately 3 hours)
Positive ankle joint mechanical work over the prosthetic limb gait cycle is a measure of propulsion capability. A prosthetic foot with greater propulsion capability may enhance gait efficiency during everyday ambulation. Normalized to body mass and the added load mass when applicable.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Feb 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. A de-identified, anonymized dataset in machine-readable format will be created and shared for all individual participant data (IPD) that underlie results in a publication. The investigators will follow 164.514(a) of the HIPAA Privacy Rule for de-identification of IPD.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Glenn Klute, PhD principal investigator
VA Puget Sound Care System
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Standard-of-care prosthetic foot, Standard-of-care prosthetic foot with heel-stiffening wedge and Standard-of-care prosthetic foot of one category greater stiffness in people with Amputation and Prosthesis User, run by VA Puget Sound Health Care System at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 12 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 12 Feb 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Vertical Ground Reaction Force Impulse (Normalized) (time frame: During study visit (approximately 3 hours)). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Feb 2026.