Leg Exercise Assistive Paddling (LEAP) Therapy for Peripheral Artery Disease
University of Nebraska
Summary
The purpose of this study is to test the effects of leg exercise assistive paddling (LEAP) therapy during prolonged sitting (PS) on vascular and functional performance in those with peripheral artery disease (PAD) and age-matched controls. LEAP therapy is a novel application of passive limb movement to enhance blood flow through the legs without muscular contractions. Specifically, LEAP therapy is the rotational passive movement of the lower leg about the knee from 90 to 180 degrees of rotation at a cadence of 1Hz. Previous literature has indicated that this movement pattern can produce robust increases in blood flow in the passively moved limb in healthy individuals, and passive limb movement may protect vascular function during PS. However, the impact of LEAP therapy to improve blood flow in the legs of those with PAD during PS is unknown. Participants will participate in a randomized cross-over design study with 2 visits (LEAP therapy and no LEAP therapy). For the first visit, participants will be randomly allocated to receive LEAP therapy during 2.5 hours of PS or not. For the second visit, participants will sit for 2.5 hours and will receive the condition that they did not previously receive. Before and after PS, the following measurements will be made: flow-mediated dilation of the popliteal and brachial arteries, arterial stiffness with tonometry techniques, microvascular vasodilatory capacity and skeletal muscle metabolic rate with near-infrared spectroscopy, autonomic nervous system function, and there will be blood drawn from the antecubital vein. After PS, participants will participate in a graded exercise test to assess functional walking capacity. Finally, during PS, near-infrared spectroscopy on the calf muscles and electrocardiogram will be collected continuously to monitor muscle oxygen availability and autonomic activity, respectively.
Description
Epidemiological studies suggest that over 200 million adults worldwide currently have peripheral artery disease (PAD), which is the buildup of atherosclerotic plaques in the arteries of the legs and is associated with high rates of morbidity and mortality. The population most suspectable to PAD is older adults, with the incidence of PAD increasing exponentially after the age of 50. This sharp age demarcation makes PAD particularly concerning for Western societies, where the proportion of older adults is steadily rising, thereby making PAD a large potential future burden to healthcare systems a…
Eligibility
- Age range
- 55–85 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: PAD subjects: * Able to provide written informed consent * 50-85 years of age * Diagnosed with Peripheral Arterial Disease (PAD) Fontaine stage II-III * Women must be postmenopausal (cessation of menses for \> 24 months) * History of exercise-induced claudication * Free of ulcers, gangrene, or necrosis of the foot, Fontaine stage IV PAD Age-matched control subjects: * Able to provide written informed consent * 50-85 years of age * No evidence of peripheral occlusive disease, ankle-brachial index \> 0.90 * Women must be postmenopausal (cessation of menses for \> 24 month…
Interventions
- OtherLEAP therapy
Knee bending from 90°-180° at 1Hz for 1 minute every 10 minutes during 2.5 hours of prolonged sitting
- Otherno LEAP therapy
2.5 hours of uninterrupted prolonged sitting (no movement)
Location
- University of Nebraska - OmahaOmaha, Nebraska