Peripheral arterial disease is a common condition affecting approximately 64% of 56-77 year olds. This condition restricts bloody supply to calf muscles. Pain occurs after walking a short distance and increases in intensity until the person stops, where the pain then gradually subsides. It can be limiting or occasionally debilitating and has been shown to have considerable deleterious effects of patients quality of life. Shock wave therapy has been shown to promote new blood vessel formation and improved healing amongst other findings. This study aims to identify whether shock wave therapy that is applied to the calf muscles causes such an effect to improve the blood supply to the calf muscles, reduce pain, improve walking ability and quality of life.

This study aims to compare the effects of extracorporeal shockwave therapy (ESWT) to placebo with use of a sham control group on walking distances in subjects with lower limb intermittent calf claudication. Extracorporeal shockwave therapy will be applied using the PiezoWave2 shockwave system. All applications will be in adherence to the manufacturer's instructions and provided by trained staff. The device will be targeted at the gastrocnemius muscles of the affected lower leg for several minutes at each treatment session. Participants in control group will undergo the identical process as if treatment were being given but with the shockwaves not being administered and a sham device alternatively used. Participants will have several assessments prior to and after the shockwave treatment in order to quantify the effect. Assessments will include Maximum Walking Distance (MWD), Claudication Distance (CD) and Quality of life questionnaires.

Inclusion Criteria:

• Patients with unilateral or bilateral intermittent calf claudication (stable for the last 3 months).
• Able to give written informed consent to participate in the study
• Age > 18
• Able to adhere to protocol and attend all follow up appointments
• Currently receiving "best medical therapy" - anti-platelet and statin medication

Exclusion Criteria:

• Current malignancy
• Allergies or intolerances of either anti-platelet medication or statin therapy
• Pregnancy (pregnancy test performed at screening if necessary)
• Metal implant near to treatment area
• Anti-coagulation medication (i.e. Warfarin)