Tourniquet cuffs are routinely used to stop blood flow in patients' arms or legs during surgery. This allows surgeons to better visualize anatomical structures during the procedure. Although complications after surgery are rare, patients sometimes suffer from pain or numbness in their limb and redness of the skin in the area where the cuff was applied. Using the lowest pressure possible minimizes the chance of these problems. Previous studies, conducted on adults, have shown that basing the cuff pressure on the minimum amount of pressure necessary to stop blood flow to the limb (known as limb occlusion pressure, or LOP) can lead to lower cuff pressures successfully being used. The goal of this study is to determine the magnitude by which tourniquet cuff pressure can be reduced in children using a tourniquet instrument capable of measuring LOP in combination with tourniquet cuffs selected to fit the size and contour of the limb. The tourniquet instrument and cuffs used in this study are all commercially available and approved for use with children.