People with narrowed blood vessels in their legs can only walk a short distance before needing to sit down due to pain in their calf muscles. Most of these patients do not follow their heart doctor's advice to walk at home because it hurts. A therapy that does not involve painful walking would be ideal for these patients to begin to treat their disease so they can eventually walk with less discomfort. We will ask patients with peripheral artery disease (PAD) to place both feet into inflatable ankle splints 30 minutes a day for 4 weeks to passively stretch their calf muscles. Before and after this 4-week program, we will measure the health and size of their leg blood vessels, the length, and function of their calf muscles and tendons, and how long they can walk without pain. We will also closely track their joint and foot movements and calf muscle oxygen levels while they walk down a hallway. People with and without risk factors for heart disease are also eligible for this study to compare differences in vascular and muscular health to patients with PAD. Volunteers without a PAD diagnosis or poor leg circulation will not undergo the 4-week stretch and no-stretch interventions.

Peripheral artery disease (PAD) and poor leg circulation patients:-4 visits to University Park Clinical Research Center ~3 hours per visit-1 blood draw-Wear a calf muscle stretching device for 30-min a day, 5 days a week, for 4 weeks and 4 weeks of no stretching-Several muscle and vascular ultrasound measurements-Walking performance tests on and off the treadmill-Wear a smartwatch to monitor physical activity during each 4-week stretch or no stretch interventionParticipants with and without risk factors for heart disease:-2 visits to University Park Clinical Research Center within the same week lasting ~3 hours per visit-Not diagnosed with PAD or poor leg circulation-1 blood draw-Several muscle and vascular ultrasound measurements-Walking performance tests on and off the treadmill

PAD participants can receive up to $450 in compensation. Participants with and without heart disease risk factors (non-PAD participants) will receive $50 for their participation.

The goal of this study is to explore how different ways of practicing, as well as paying attention, affect learning to walk while using an ankle exoskeleton. This pilot study will look at whether changing the settings of the exoskeleton and walking conditions frequently or not very often helps people walk better in follow-up tests. It will also examine if asking people to focus on their body (internal focus) or on their surroundings (external focus) improves their walking.

There will be three in-person visits over two days, walking in a lower limb exoskeleton will occur at all three visits.

$40.00