Lower Limb Amputation Below Knee (Injury)NCT05124652
An Automatically Adjusting Prosthetic Socket for People With Transtibial Amputation
A study testing Auto Adjusting Prosthesis in people with Lower Limb Amputation Below Knee (Injury) and Diurnal Residual Limb Fluid Volume Fluctuation, run by University of Washington at 1 site in United States.
Trial summary
People with leg amputations often experience daily changes in the size (volume) of their residual limb. These daily changes can cause a prosthesis to fit poorly. They can also cause limb problems like pain or skin breakdown. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Lower Limb Amputation Below Knee (Injury), Diurnal Residual Limb Fluid Volume Fluctuation
- What is being tested?
- Auto Adjusting Prosthesis
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteUnited States
- Study dates
- 18 Oct 2021to Jun 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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
- Healthy volunteers accepted
- Adult, Older adult
- 18 years or older
- Unilateral or bilateral trans-tibial amputation at least 12 months prior
- Have a limb of length 9 cm or greater
- Are capable of at least 5 minutes of continuous walking
- Are capable of at least 1 hour of intermittent walking
- Regularly use a definitive prosthesis with a pin-lock suspension system and no or few pads
- Have adequate sensation to verbalize a socket that is too large or too small to be tolerated
- Do not regularly use assistive devices (e.g., cane, walker) for ambulation
- Do not have open wounds on their residual limb at the time of enrollment
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Tessa S Viljamaa contact
United States1 site, 1 recruiting
- Recruiting
William H. Foege Hall
Seattle, Washington, 98105
Katheryn Allyn, 206-390-0228, kate@allyn.org
About this study
Official title: An Automatically-adjusting Prosthetic Socket for People With Transtibial Amputation
People with leg amputations often experience daily changes in the size (volume) of their residual limb. These daily changes can cause a prosthesis to fit poorly. They can also cause limb problems like pain or skin breakdown. Prosthetic socket systems that accommodate limb volume changes can help address these issues, but they require users to make adjustments throughout the day. The aim of this research is to create a system that will automatically adjust the fit of the socket and create a well-fitting prosthesis for people with leg amputations who experience volume fluctuations when using their prosthesis.
Read the detailed description
he goal of this research is to determine if an automatic-adjusting prosthetic socket produces better participant outcomes than a manually-adjusting socket or a standard of care control in people with trans-tibial limb amputation. Prosthesis users will wear each socket configuration for 2 weeks. Endpoints will include self-reported comfort, convenience, and fatigue; residual limb health; wear time; activities time; and variability in socket fit. Each condition will be tested separately in a cross-over study design, including a 2-week washout period between the conditions. This aim will use a crossover randomized trial to evaluate the importance of the socket condition The three test conditions will be (1) an automatic-adjusting socket; and (2) a manual-adjusting socket; and (3) a standard of care (adjust socks) control in which socket adjustment is locked. Participants will test each of these three conditions in a random order. There will be a 2-week washout period between test conditions. Participation will begin with an initial sessions where the researchers will evaluate inclusion criteria, collect demographic information, conduct a brief bioimpedance test and thermal imaging test, scan the participant's existing socket and instrument the participant's traditional socket with a monitor to collect activity data for 2 weeks while the investigational prosthesis is fabricated. When the investigational prosthesis is prepared, participants will return to the lab. Self-report questionnaires will be completed, and residual limb health assessed. The participant will be trained on how to operate the socket. The socket will be set to the first condition (order of conditions randomly selected). After using the socket for 3 to 5 days, the researchers will go to the participant's location for a check-in visit. The participant will have an opportunity to ask questions and discuss any issues they are having with the socket. The researchers will make sure the socket is functioning properly. After 2 weeks total, participants will return to the lab and complete self-report questionnaires and have their residual limb health assessed. They will participate in an interview about their experience wearing the socket. After a 2-week washout period, they will conduct the same procedure wearing another socket condition. After another 2-week washout period, they will conduct the same procedure wearing the remaining socket condition.
- Being tested
- Auto Adjusting Prosthesis
- Keywords
- amputee, prosthetic
- Medical subject headings
- Wounds and Injuries
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Auto Adjusting ProsthesisDevice
Participants will test the auto adjusting prosthesis. The prosthesis will be able to move up to 3 panels built into the socket walls to expand or tighten the socket's fit. The auto adjustments will take place during periods of sitting, standing, or walking. Manual adjustments will also be possible either via the researcher controlling the prosthesis or via the key fob developed in the first aim.
| Study group | Role | What they receive |
|---|---|---|
| Focus Group Testing | No intervention | Focus group testing of key-fob device to control adjusting socket system |
| In-Lab, Crossover Study | Experimental | Testing of auto-adjusting algorithm in-lab. Participants will carry out a structured protocol wearing the socket in all modes. Order will be randomly assigned. Receives: Device: Auto Adjusting Prosthesis |
| Out-of-Lab Crossover Study | Experimental | Evaluate socket performance in user free-living environments. Participants will use the prosthesis in all modes by end of study, order will be randomly assigned. Receives: Device: Auto Adjusting Prosthesis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Socket Comfort Score
Participants in Aim 2 and Aim 3 will test various configurations of the auto adjustment algorithm. Socket comfort score will be asked at various time points during testing, and overall changes in this metric will be calculated from the start and end of session.
Measured: through study completion, an average of 1 year
Integral Absolute Error of Control System
Calculated error will be measured through each test session, both in and out of lab.
Measured: through study completion, an average of 1 year
Secondary outcomes (5)
Percent change in Limb Fluid Volume
Participant's limb fluid volume will be measured during the structured in-lab protocol (Aim 2), and changes will be compared against an initial reference point of activity during which no interventions will take place.
Measured: through study completion, an average of 1 year
Residual limb health
Data collected using a standard skin assessment protocol and an IR imaging camera will be used. For IR data, thermal recovery time will be calculated and a difference map of TRT between the beginning and end test condition created
Measured: Baseline and through study completion, an average of 1 year
Prosthesis wear time
Socket fit sensor data will be used
Measured: Up to 12 weeks
Time of activities
Durations of walking, standing, sitting, sitting partially doffed, and doffed will be calculated for each day, using socket fit sensor and pin sensor data
Measured: Up to 12 weeks
Variability in socket fit
This will be calculated from socket sensor SFM data
Measured: Up to 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Nov 2021
- Study start18 Oct 2021
- Primary completionMar 2027 (estimated)
- Study completionJun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Lower Limb Amputation Below Knee (Injury)Studies of the same condition, open and under way.
- More trials run by University of WashingtonThe 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 N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- All aims will be conducted as randomized control trials and test various developments to the auto adjusting system, with each previous aim informing the next.
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Washington
- Sponsor type
- University, hospital or other
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Responsible party
- Principal investigator, Joan E Sanders, University of Washington
- Investigators
- Joan E Sanders, PhD, Principal investigator, University of Washington
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05124652
- Sponsor's protocol ID
- STUDY00009418
- Other IDs
- 1R01HD103815-01A1
- Status last verified
- Mar 2026
- First submitted
- 20 Oct 2021
- Last updated
- 7 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 7 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Automatically-adjusting Prosthetic Socket for People With Transtibial Amputation
- ClinicalTrials.gov ID
- NCT05124652
- Acronym / sponsor ID
- STUDY00009418
- Keywords
- amputee, prosthetic
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- University of WashingtonUniversity, hospital or other
- Collaborators
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Study start
- 18 Oct 2021 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Jun 2027 (estimated)
- First posted
- 18 Nov 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
People with leg amputations often experience daily changes in the size (volume) of their residual limb. These daily changes can cause a prosthesis to fit poorly. They can also cause limb problems like pain or skin breakdown. Prosthetic socket systems that accommodate limb volume changes can help address these issues, but they require users to make adjustments throughout the day. The aim of this research is to create a system that will automatically adjust the fit of the socket and create a well-fitting prosthesis for people with leg amputations who experience volume fluctuations when using their prosthesis.
Detailed description
he goal of this research is to determine if an automatic-adjusting prosthetic socket produces better participant outcomes than a manually-adjusting socket or a standard of care control in people with trans-tibial limb amputation. Prosthesis users will wear each socket configuration for 2 weeks. Endpoints will include self-reported comfort, convenience, and fatigue; residual limb health; wear time; activities time; and variability in socket fit. Each condition will be tested separately in a cross-over study design, including a 2-week washout period between the conditions. This aim will use a crossover randomized trial to evaluate the importance of the socket condition The three test conditions will be (1) an automatic-adjusting socket; and (2) a manual-adjusting socket; and (3) a standard of care (adjust socks) control in which socket adjustment is locked. Participants will test each of these three conditions in a random order. There will be a 2-week washout period between test conditions. Participation will begin with an initial sessions where the researchers will evaluate inclusion criteria, collect demographic information, conduct a brief bioimpedance test and thermal imaging test, scan the participant's existing socket and instrument the participant's traditional socket with a monitor to collect activity data for 2 weeks while the investigational prosthesis is fabricated. When the investigational prosthesis is prepared, participants will return to the lab. Self-report questionnaires will be completed, and residual limb health assessed. The participant will be trained on how to operate the socket. The socket will be set to the first condition (order of conditions randomly selected). After using the socket for 3 to 5 days, the researchers will go to the participant's location for a check-in visit. The participant will have an opportunity to ask questions and discuss any issues they are having with the socket. The researchers will make sure the socket is functioning properly. After 2 weeks total, participants will return to the lab and complete self-report questionnaires and have their residual limb health assessed. They will participate in an interview about their experience wearing the socket. After a 2-week washout period, they will conduct the same procedure wearing another socket condition. After another 2-week washout period, they will conduct the same procedure wearing the remaining socket condition.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- All aims will be conducted as randomized control trials and test various developments to the auto adjusting system, with each previous aim informing the next.
| Arm | Type | Receives |
|---|---|---|
| Focus Group Testing | No intervention | –Focus group testing of key-fob device to control adjusting socket system |
| In-Lab, Crossover Study | Experimental | Device: Auto Adjusting ProsthesisTesting of auto-adjusting algorithm in-lab. Participants will carry out a structured protocol wearing the socket in all modes. Order will be randomly assigned. |
| Out-of-Lab Crossover Study | Experimental | Device: Auto Adjusting ProsthesisEvaluate socket performance in user free-living environments. Participants will use the prosthesis in all modes by end of study, order will be randomly assigned. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
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 |
|---|---|---|
| Auto Adjusting ProsthesisParticipants will test the auto adjusting prosthesis. The prosthesis will be able to move up to 3 panels built into the socket walls to expand or tighten the socket's fit. The auto adjustments will take place during periods of sitting, standing, or walking. Manual adjustments will also be possible either via the researcher controlling the prosthesis or via the key fob developed in the first aim. | Device | In-Lab, Crossover Study, Out-of-Lab Crossover Study |
Primary outcome
Socket Comfort Score
Time frame: through study completion, an average of 1 year
Participants in Aim 2 and Aim 3 will test various configurations of the auto adjustment algorithm. Socket comfort score will be asked at various time points during testing, and overall changes in this metric will be calculated from the start and end of session.
Integral Absolute Error of Control System
Time frame: through study completion, an average of 1 year
Calculated error will be measured through each test session, both in and out of lab.
5 secondary outcomes
Percent change in Limb Fluid Volume
Time frame: through study completion, an average of 1 year
Residual limb health
Time frame: Baseline and through study completion, an average of 1 year
Prosthesis wear time
Time frame: Up to 12 weeks
Time of activities
Time frame: Up to 12 weeks
Variability in socket fit
Time frame: Up to 12 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 May 2026.
Related trials for Lower Limb Amputation Below Knee (Injury)
Recruiting
REsistance and LOADing Exercise for Bone Health
Amputation of Lower Limb Below Knee, Amputation, Traumatic
Recruiting
Restoration of Normative Postural Control
Lower Limb Amputation Below Knee (Injury)
Recruiting
Prosthetic Performance Enhancement Trial
Amputation, Lower Limb Amputation Below Knee (Injury)
Active, not recruitingObservational study
C-STAR Movement Database
Stroke, Parkinson Disease
Recruiting
Caesar Foot Take-Home Validation Testing
Prosthesis User, Lower Limb Amputation Below Knee (Injury)
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.
Tessa S Viljamaa contact
Joan E Sanders, PhD principal investigator
University of Washington
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Auto Adjusting Prosthesis in people with Lower Limb Amputation Below Knee (Injury) and Diurnal Residual Limb Fluid Volume Fluctuation, run by University of Washington 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?
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: looking for participants now, as of the sponsor's last update on 7 May 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Katheryn Allen, CPO (206-390-0228, kate@allyn.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Socket Comfort Score (time frame: through study completion, an average of 1 year). The study lists 2 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 7 May 2026.