There are a number of risk factors for development of chronic pain that have been evaluated including age, gender, type and duration of surgery, duration of pain prior to surgery and tourniquet application. There is some scientific evidence from animal studies demonstrating that prolonged tourniquet application can result in lack of oxygen supply to nerves, and subsequent nerve damage resulting in chronic pain. This theory has not been proven in humans. In this study the investigators will indirectly assess the evidence for abnormalities caused by tourniquet application on subjects' nerves using well established devices to determine the function of these nerves.