Ischemic Conditioning for Peripheral Arterial Disease
Trial Summary
What is the purpose of this trial?
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.
Research Team
Lindsay Slater, PhD
Principal Investigator
University of Illinois at Chicago
Eligibility Criteria
This trial is for adults over 18 with a history of unilateral lower limb amputation due to peripheral artery disease, who can walk continuously for at least 10 minutes. They must not use walking aids and should have no neurological disorders affecting gait, heart failure, adverse reactions to ultrasound gel, thrombosis, sickle cell trait or hypertension.Inclusion Criteria
Exclusion Criteria
Timeline
Screening
Participants are screened for eligibility to participate in the trial
Treatment
Participants undergo ischemic conditioning with either low or high compression to assess changes in quadriceps strength and gait mechanics
Follow-up
Participants are monitored for safety and effectiveness after treatment
Treatment Details
Interventions
- Ischemic Conditioning High - Active Comparator
- Ischemic Conditioning Low - Sham Comparator
Find a Clinic Near You
Who Is Running the Clinical Trial?
University of Illinois at Chicago
Lead Sponsor
American Heart Association
Collaborator