The goal of this clinical trial is to assess the effects of passive calf muscle stretching in patients diagnosed with peripheral artery disease (PAD). The main question it aims to answer are:

1. To determine if daily calf muscle stretching at home improves calf muscle and vascular health.
2. To determine if daily calf muscle stretching at home improves walking performance.

Participants will use inflatable ankle splints for 30 minutes a day, 5 days a week for 4-weeks on both days and 4-weeks of no stretching.

Patients with peripheral artery disease will passively stretch their calf muscles using a stretch device on both feet for 30 minutes a day for 4 weeks. Blood vessel health and size, length and function of the calf muscles and tendons and walking performance will be measured. Joint and foot movements as well as calf muscle oxygen levels will be measured during walking performance tests.

Inclusion Criteria:

• Presence of PAD
• Stable condition (PAD symptoms) for at least 3 months
• Age 40-85
• Men and women who are not pregnant or nursing

Exclusion Criteria:

• Ischemic leg pain at rest; critical limb ischemia (ulceration or gangrene)
• Any condition other than PAD that limits the ability to walk
• Major surgery or lower extremity revascularization surgery in the past 6 months
• Myocardial infarction within past 6 months or unstable angina
• Severe lung disease (on supplemental oxygen or frequently use rescue inhalers)
• Participants with non-compressible vessels (ABI > 1.40)
• Habitual exercise (30 minutes of continuous activity on 3 or more days per week)
• Current tobacco smoker or use of nicotine-containing products
• Pregnant or nursing women
• History or ankle reconstruction or surgery Recent history (<1 year) of injuries to the ankle, Achilles tendon, or feet
• History of rheumatoid arthritis or other degenerative joint disease
• Major medical illness treatment during the prior 12 months
• Uncontrolled hypertension
• Uncontrolled diabetes
• Inability to walk on a treadmill at a slow pace (1.0 mile/hour)

Due to the nature of the intervention, participants will not be blinded to stretching vs no-stretching interventions. The study team will be blinded to intervention order when performing data analysis.