Peripheral Arterial DiseaseNCT04937179
The Effect of Ischemic Conditioning on Strength and Ambulation in Subjects with PAD
A study testing Ischemic Conditioning High - Active Comparator in people with Peripheral Arterial Disease and Peripheral Vascular Disease, run by University of Illinois Chicago at 1 site in United States.
Trial summary
Lower limb amputation is common in the United States, with approximately 150,000 amputations annually. Most individuals walking with a prosthesis demonstrate asymmetrical loading-i.e., they favor the amputated side by placing more weight and increased ground reaction forces through the intact limb-which likely… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Peripheral Arterial Disease, Peripheral Vascular Disease, Amputation
- What is being tested?
- Ischemic Conditioning High - Active Comparator
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 21 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jul 2022to 31 Dec 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
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
- 18 years or older
- Able to ambulate independently without the use of aids (i.e., walking cane)
- Able to walk at least 10 minutes continuously without stopping
- History of diagnosed peripheral artery disease.
- For Amputees: History lower limb unilateral transtibial or transfemoral amputation.
Who cannot join
- Inability to give informed consent
- neurological disorder that affects gait
- two or more falls within the previous 12 months
- currently pregnant (or intend to become pregnant while participating in study)
- history of any condition where fatiguing contractions or resisted leg contractions are contraindicated
- blood clots in the leg, or any condition in which compression of the thigh or transient ischemia is contraindicated (e.g. open wounds in the leg).
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- history of hypertension
- history of heart failure
- Head injury within the previous 6 months
- Seizure disorder
- Adverse reaction to ultrasound gel
- History of thrombosis
- History of sickle cell trait
Trial locations and contacts
1 site in 1 country.
United States1 site
UIC Physical Therapy Faculty Practice
Chicago, Illinois, 60608
About this study
Official title: The Effect of Ischemic Conditioning on Strength and Ambulation in Subjects with Peripheral Artery Disease (PAD)
Lower limb amputation is common in the United States, with approximately 150,000 amputations annually. Most individuals walking with a prosthesis demonstrate asymmetrical loading-i.e., they favor the amputated side by placing more weight and increased ground reaction forces through the intact limb-which likely contributes to increased metabolic cost of walking. Lack of adequate muscular strength in the lower limb to attenuate these forces places increased stress on the joints, which may be displaced proximally, and may play a role in reported knee and hip pain in the intact limb.
Lower limb muscle weakness following amputation has been well documented. Increasing quadriceps strength is important after an amputation because it is positively correlated with gait speed. Gait speed may also be associated with successful community mobility, which leads to improved quality of life following amputation. Individuals with amputation who resume an active lifestyle are able to maintain strength. However, these individuals represent a minority of persons with lower limb amputation; most individuals report more barriers than motivators to adopt an active lifestyle.
Read more
Ischemic conditioning (IC) may strengthen leg muscles and reduce the metabolic cost of activity after amputation. In IC, the limb is exposed to brief, repeated bouts of ischemia (reduced blood flow) immediately followed by reperfusion. IC has been shown to improve muscle performance in healthy and diseased populations. IC has also been used more recently in patients with peripheral artery disease (PAD) as an intervention to improve function, such as walking ability. Acute exposure to IC increases muscle strength and activation, both in healthy, active individuals and in those with severe neuromuscular dysfunction, such as stroke survivors. IC also attenuates muscular fatigue. Increased fatigue resistance at submaximal contraction levels following IC may be due to increased neural activation of skeletal muscle. Changes in neural activation of muscle may be particularly beneficial during cortical reorganization after amputation. Reduced quadriceps fatigue during submaximal activities may also drive changes in gait kinematics, such as increased knee flexion during loading and mid-stance. Exposure to IC may also increase the oxidative properties of skeletal muscle, offering a direct pathway to reduce metabolic cost. Therefore, IC may lead to cellular changes that lower the metabolic cost of activity.
The primary aim of this study is to quantify the benefits of acute and chronic IC on quadriceps strength and walking economy in individuals with PAD and history of lower limb amputation.
- Conditions
- Peripheral Arterial Disease, Peripheral Vascular Disease, Amputation, Lower Limb Amputation Knee, Lower Limb Amputation Above Knee (Injury), Lower Limb Amputation Below Knee (Injury)
- Being tested
- Ischemic Conditioning Low - Sham Comparator, Ischemic Conditioning High - Active Comparator
- Medical subject headings
- Peripheral Arterial Disease, Peripheral Vascular Diseases, Wounds and Injuries
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ischemic Conditioning Low - Sham ComparatorProcedure or surgery
The use of a Hokanson rapid inflator cuff to restrict blood flow at 25mmHg for 5 minutes followed by a 5 minute reperfusion period, repeated for 5 cycles.
Ischemic Conditioning High - Active ComparatorProcedure or surgery
The use of a Hokanson rapid inflator cuff to restrict blood flow at 225mmHg for 5 minutes followed by a 5 minute reperfusion period, repeated for 5 cycles.
| Study group | Role | What they receive |
|---|---|---|
| Ischemic Conditioning Low | Sham comparator | Blood flow restriction with low compression Receives: Procedure: Ischemic Conditioning Low - Sham Comparator |
| Ischemic Conditioning High | Active comparator | Blood flow restriction with high compression Receives: Procedure: Ischemic Conditioning High - Active Comparator |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in quadriceps strength
Quadriceps strength assessed by a Biodex dynamometer
Measured: through study completion, an average of 6 weeks
Change in gait kinematics
Gait mechanics assessed by joint angles using Vicon cameras and reflective markers
Measured: through study completion, an average of 6 weeks
Change in gait kinetics
Gait mechanics assessed by joint forces using a Bertec instrumented treadmill in combination with gait kinematics
Measured: through study completion, an average of 6 weeks
Change in gait metabolics
Assessment of oxygen consumption during walking using a metabolic cart
Measured: through study completion, an average of 6 weeks
Secondary outcomes (1)
Six-minute walk test
Measurement of distance walked in six minutes
Measured: through study completion, an average of 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jun 2021
- Study start1 Jul 2022
- Primary completion31 Dec 2024
- Study completion31 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Peripheral Arterial DiseaseStudies of the same condition, open and under way.
- More trials run by University of Illinois ChicagoThe 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
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 21 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Illinois Chicago
- Sponsor type
- University, hospital or other
- Collaborators
- American Heart Association
- Responsible party
- Principal investigator, Lindsay Hannigan, University of Illinois Chicago
- Investigators
- Lindsay Slater, PhD, Principal investigator, University of Illinois Chicago
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04937179
- Sponsor's protocol ID
- 2021-0223
- Other IDs
- 20CDA35310419
- Status last verified
- Feb 2025
- First submitted
- 27 May 2021
- Last updated
- 27 Feb 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Ischemic Conditioning on Strength and Ambulation in Subjects with Peripheral Artery Disease (PAD)
- ClinicalTrials.gov ID
- NCT04937179
- Acronym / sponsor ID
- 2021-0223
- Conditions
- Peripheral Arterial Disease, Peripheral Vascular Disease, Amputation, Lower Limb Amputation Knee, Lower Limb Amputation Above Knee (Injury), Lower Limb Amputation Below Knee (Injury)
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 21 participants (actual)
- Lead sponsor
- University of Illinois ChicagoUniversity, hospital or other
- Collaborators
- American Heart Association
- Study start
- 1 Jul 2022 (actual)
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 23 Jun 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.
Lower limb amputation is common in the United States, with approximately 150,000 amputations annually. Most individuals walking with a prosthesis demonstrate asymmetrical loading-i.e., they favor the amputated side by placing more weight and increased ground reaction forces through the intact limb-which likely contributes to increased metabolic cost of walking. Lack of adequate muscular strength in the lower limb to attenuate these forces places increased stress on the joints, which may be displaced proximally, and may play a role in reported knee and hip pain in the intact limb.
Lower limb muscle weakness following amputation has been well documented. Increasing quadriceps strength is important after an amputation because it is positively correlated with gait speed. Gait speed may also be associated with successful community mobility, which leads to improved quality of life following amputation. Individuals with amputation who resume an active lifestyle are able to maintain strength. However, these individuals represent a minority of persons with lower limb amputation; most individuals report more barriers than motivators to adopt an active lifestyle.
Ischemic conditioning (IC) may strengthen leg muscles and reduce the metabolic cost of activity after amputation. In IC, the limb is exposed to brief, repeated bouts of ischemia (reduced blood flow) immediately followed by reperfusion. IC has been shown to improve muscle performance in healthy and diseased populations. IC has also been used more recently in patients with peripheral artery disease (PAD) as an intervention to improve function, such as walking ability. Acute exposure to IC increases muscle strength and activation, both in healthy, active individuals and in those with severe neuromuscular dysfunction, such as stroke survivors. IC also attenuates muscular fatigue. Increased fatigue resistance at submaximal contraction levels following IC may be due to increased neural activation of skeletal muscle. Changes in neural activation of muscle may be particularly beneficial during cortical reorganization after amputation. Reduced quadriceps fatigue during submaximal activities may also drive changes in gait kinematics, such as increased knee flexion during loading and mid-stance. Exposure to IC may also increase the oxidative properties of skeletal muscle, offering a direct pathway to reduce metabolic cost. Therefore, IC may lead to cellular changes that lower the metabolic cost of activity.
The primary aim of this study is to quantify the benefits of acute and chronic IC on quadriceps strength and walking economy in individuals with PAD and history of lower limb amputation.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Ischemic Conditioning Low | Sham comparator | Procedure: Ischemic Conditioning Low - Sham ComparatorBlood flow restriction with low compression |
| Ischemic Conditioning High | Active comparator | Procedure: Ischemic Conditioning High - Active ComparatorBlood flow restriction with high compression |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- 18 years or older
- Able to ambulate independently without the use of aids (i.e., walking cane)
- Able to walk at least 10 minutes continuously without stopping
- History of diagnosed peripheral artery disease.
- For Amputees: History lower limb unilateral transtibial or transfemoral amputation.
Key exclusion criteria (13 listed)
- Inability to give informed consent
- neurological disorder that affects gait
- two or more falls within the previous 12 months
- currently pregnant (or intend to become pregnant while participating in study)
- history of any condition where fatiguing contractions or resisted leg contractions are contraindicated
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 |
|---|---|---|
| Ischemic Conditioning Low - Sham ComparatorThe use of a Hokanson rapid inflator cuff to restrict blood flow at 25mmHg for 5 minutes followed by a 5 minute reperfusion period, repeated for 5 cycles. | Procedure or surgery | Ischemic Conditioning Low |
| Ischemic Conditioning High - Active ComparatorThe use of a Hokanson rapid inflator cuff to restrict blood flow at 225mmHg for 5 minutes followed by a 5 minute reperfusion period, repeated for 5 cycles. | Procedure or surgery | Ischemic Conditioning High |
Primary outcome
Change in quadriceps strength
Time frame: through study completion, an average of 6 weeks
Quadriceps strength assessed by a Biodex dynamometer
Change in gait kinematics
Time frame: through study completion, an average of 6 weeks
Gait mechanics assessed by joint angles using Vicon cameras and reflective markers
Change in gait kinetics
Time frame: through study completion, an average of 6 weeks
Gait mechanics assessed by joint forces using a Bertec instrumented treadmill in combination with gait kinematics
Change in gait metabolics
Time frame: through study completion, an average of 6 weeks
Assessment of oxygen consumption during walking using a metabolic cart
1 secondary outcome
Six-minute walk test
Time frame: through study completion, an average of 6 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Feb 2025.
- Individual participant dataSharing planned: No
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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.
Lindsay Slater, PhD principal investigator
University of Illinois Chicago
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ischemic Conditioning High - Active Comparator in people with Peripheral Arterial Disease and Peripheral Vascular Disease, run by University of Illinois Chicago 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 5 inclusion and 13 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 27 Feb 2025. 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. Some participants in this study may receive a placebo. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Change in quadriceps strength (time frame: through study completion, an average of 6 weeks). The study lists 4 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 27 Feb 2025.