Traumatic Amputation of Lower ExtremityNCT00869947
Effects of Wearing a Powered Ankle-Foot Prosthesis on Amputee Walking
A study testing Powered ankle-foot prosthesis and No device in people with Traumatic Amputation of Lower Extremity, run by US Department of Veterans Affairs at 1 site in United States.
Trial summary
Amputees wearing a conventional prosthesis require 20-30% more metabolic energy to walk at the same speeds as non-amputees and this discrepancy is more apparent at faster walking speeds. Amputees choose to walk at speeds 30-40% slower than non-amputees. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Traumatic Amputation of Lower Extremity
- What is being tested?
- Powered ankle-foot prosthesis and No device
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteUnited States
- Study dates
- Mar 2009to Jan 2013
- 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 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 20 healthy adult volunteers, 10 unilateral trans-tibial amputees and 10 matched non-amputees, will be recruited and screened
- Amputees must be at least 1 year post-amputation, high-functioning (at least a K3 level of ambulation), and whose cause of amputation is either traumatic or vascular. Medicare defines a K3 level amputee as an ambulator who has the ability or potential for prosthetic ambulation with variable cadence, who has the ability to traverse most environmental barriers and who may have vocational, therapeutic, or exercise activity that demands prosthetic utilization beyond simple locomotion
Who cannot join
- None
Trial locations and contacts
1 site in 1 country.
United States1 site
VA Medical Center, Providence
Providence, Rhode Island, 02908
About this study
Amputees wearing a conventional prosthesis require 20-30% more metabolic energy to walk at the same speeds as non-amputees and this discrepancy is more apparent at faster walking speeds. Amputees choose to walk at speeds 30-40% slower than non-amputees. Preferred walking speed is likely influenced by elevated metabolic energy, but the underlying reason for slower preferred walking speeds is not fully understood. Unilateral amputees exhibit highly asymmetrical gait patterns that likely require more metabolic energy and impair functional mobility, increasing the risk of degenerative joint disease, osteo-arthritis and lower back pain. Improvements in prosthetic devices could enhance mobility in amputees, thus positively effecting rehabilitation and ambulation in veterans. A prosthesis that allows amputees to reduce metabolic energy would be especially useful for rehabilitation in older, ill individuals with reduced exercise capacities and could literally restore walking ability in people that are currently non-ambulatory.
Hypotheses. Amputees wearing the Massachusetts Institute of Technology (MIT) Powered Ankle-Foot (PAF) prosthesis will have a lower metabolic cost, faster preferred walking speed, and improved gait symmetry during walking than amputees wearing a conventional prosthesis and will have nearly the same metabolic cost, preferred walking speed, and gait symmetry during walking as age, gender, height, and weight matched non-amputees.
- Conditions
- Traumatic Amputation of Lower Extremity
- Being tested
- Powered ankle-foot prosthesis, No device
- Keywords
- Unilateral below the knee amputation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Powered ankle-foot prosthesisDevice
The powered ankle-foot prosthesis is comprised of a series-elastic actuator (SEA) and an elastic leaf spring. This technology has been previously developed for robotic and human rehabilitation applications. The SEA allows for precise force control of the ankle joint, thus mimicking the spring-like behavior of the human ankle, as well as providing adequate energy for forward progression of the body. From the early stance period to the mid-stance period of walking, the SEA will be controlled so that the ankle joint behaves like a spring. During the late stance period, the SEA will be employed to power the forward movement of the body. The elastic leaf spring will provide shock absorption during foot strike, energy storage during early stance, and energy return during late stance.
No deviceOther
| Study group | Role | What they receive |
|---|---|---|
| Prosthesis | Experimental | Powered ankle-foot prosthesis and passive-elastic prosthesis Receives: Device: Powered ankle-foot prosthesis |
| Non-amputee | Experimental | Non-amputee Receives: Other: No device |
What is being measured
The primary outcome is the main question the study is designed to answer.
Metabolic Cost of Transport
We measured and compared gross rates of oxygen consumption and carbon dioxide production using a portable metabolic analysis system (Cosmed K4b2, IT) while participants walked at five constance velocities (0.75, 1.00, 1.25, 1.50 and 1.75 m/s) on a level treadmill (SoleFitness F85). We calculated average steady-state metabolic power in Watts (W) from 4-6 min of each trial using a standard equation. Then, we divided the metabolic power by each participant's weight and velocity to calculate the metabolic cost of transport (J/Nm).
Measured: 1 year
Secondary outcomes (2)
Preferred Walking Velocity
We determined preferred walking velocity by incrementally increasing and decreasing treadmill velocity until each participant ascertained the velocity that they felt most comfortable.
Measured: 1 year
Trailing Leg Step-to-step Transition Work
We calculated step-to-step transition work, the work done by each individual leg on the center of mass during transitions, using the individual limbs method described by Donelan et al. 2002. Trailing leg step-to-step transition work quantifies the amount of push-off work done by the trailing leg when both feet are on the ground during walking. Work (J) is normalized to each subject's mass (kg).
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Mar 2009 (estimated)
- Study startMar 2009
- Primary completionJun 2011
- Study completionJan 2013
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 Traumatic Amputation of Lower ExtremityStudies 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
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Factorial
- Masking
- None (open label)
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- US Department of Veterans Affairs
- Sponsor type
- US federal agency
- Collaborators
- Massachusetts Institute of Technology
- Responsible party
- Sponsor
- Investigators
- Alena Grabowski, PhD BA, Principal investigator, VA Eastern Colorado Health Care System, Denver, CO
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00869947
- Sponsor's protocol ID
- A6749-M
- Status last verified
- Jan 2014
- First submitted
- 24 Mar 2009
- Last updated
- 25 Feb 2014
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Feb 2014. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Wearing a Powered Ankle-Foot Prosthesis on Amputee Walking
- ClinicalTrials.gov ID
- NCT00869947
- Acronym / sponsor ID
- A6749-M
- Conditions
- Traumatic Amputation of Lower Extremity
- Keywords
- Unilateral below the knee amputation
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- US Department of Veterans AffairsUS federal agency
- Collaborators
- Massachusetts Institute of Technology
- Study start
- Mar 2009
- Primary completion
- Jun 2011 (actual)
- Study completion
- Jan 2013 (actual)
- First posted
- 26 Mar 2009 (estimated)
- Results
- Posted 25 Feb 2014
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Amputees wearing a conventional prosthesis require 20-30% more metabolic energy to walk at the same speeds as non-amputees and this discrepancy is more apparent at faster walking speeds. Amputees choose to walk at speeds 30-40% slower than non-amputees. Preferred walking speed is likely influenced by elevated metabolic energy, but the underlying reason for slower preferred walking speeds is not fully understood. Unilateral amputees exhibit highly asymmetrical gait patterns that likely require more metabolic energy and impair functional mobility, increasing the risk of degenerative joint disease, osteo-arthritis and lower back pain. Improvements in prosthetic devices could enhance mobility in amputees, thus positively effecting rehabilitation and ambulation in veterans. A prosthesis that allows amputees to reduce metabolic energy would be especially useful for rehabilitation in older, ill individuals with reduced exercise capacities and could literally restore walking ability in people that are currently non-ambulatory.
Hypotheses. Amputees wearing the Massachusetts Institute of Technology (MIT) Powered Ankle-Foot (PAF) prosthesis will have a lower metabolic cost, faster preferred walking speed, and improved gait symmetry during walking than amputees wearing a conventional prosthesis and will have nearly the same metabolic cost, preferred walking speed, and gait symmetry during walking as age, gender, height, and weight matched non-amputees.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Factorial
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Prosthesis | Experimental | Device: Powered ankle-foot prosthesisPowered ankle-foot prosthesis and passive-elastic prosthesis |
| Non-amputee | Experimental | Other: No deviceNon-amputee |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- 20 healthy adult volunteers, 10 unilateral trans-tibial amputees and 10 matched non-amputees, will be recruited and screened
- Amputees must be at least 1 year post-amputation, high-functioning (at least a K3 level of ambulation), and whose cause of amputation is either traumatic or vascular. Medicare defines a K3 level amputee as an ambulator who has the ability or potential for prosthetic ambulation with variable cadence, who has the ability to traverse most environmental barriers and who may have vocational, therapeutic, or exercise activity that demands prosthetic utilization beyond simple locomotion
Key exclusion criteria (1 listed)
- None
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 |
|---|---|---|
| Powered ankle-foot prosthesisThe powered ankle-foot prosthesis is comprised of a series-elastic actuator (SEA) and an elastic leaf spring. This technology has been previously developed for robotic and human rehabilitation applications. The SEA allows for precise force control of the ankle joint, thus mimicking the spring-like behavior of the human ankle, as well as providing adequate energy for forward progression of the body. From the early stance period to the mid-stance period of walking, the SEA will be controlled so that the ankle joint behaves like a spring. During the late stance period, the SEA will be employed to power the forward movement of the body. The elastic leaf spring will provide shock absorption during foot strike, energy storage during early stance, and energy return during late stance. | Device | Prosthesis |
| No device | Other | Non-amputee |
Primary outcome
Metabolic Cost of Transport
Time frame: 1 year
We measured and compared gross rates of oxygen consumption and carbon dioxide production using a portable metabolic analysis system (Cosmed K4b2, IT) while participants walked at five constance velocities (0.75, 1.00, 1.25, 1.50 and 1.75 m/s) on a level treadmill (SoleFitness F85). We calculated average steady-state metabolic power in Watts (W) from 4-6 min of each trial using a standard equation. Then, we divided the metabolic power by each participant's weight and velocity to calculate the metabolic cost of transport (J/Nm).
2 secondary outcomes
Preferred Walking Velocity
Time frame: 1 year
Trailing Leg Step-to-step Transition Work
Time frame: 1 year
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Feb 2014.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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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.
Alena Grabowski, PhD BA principal investigator
VA Eastern Colorado Health Care System, Denver, CO
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Powered ankle-foot prosthesis and No device in people with Traumatic Amputation of Lower Extremity, run by US Department of Veterans Affairs 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 2 inclusion and 1 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 25 Feb 2014. 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 25 Feb 2014). 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?
Metabolic Cost of Transport (time frame: 1 year). 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 25 Feb 2014.