special subjects
Rehabilitative Measures for Treatment of Pain and Inflammation
Cold
The choice between heat and cold therapies is often empiric. When heat does not work, cold is applied. However, for acute injury or pain, cold seems to be better than heat. Cold may help relieve muscle spasm, myofascial or traumatic pain, low back pain, and acute inflammation; cold may also help induce some local anesthesia. Cold is usually used during the first few hours or the day after an injury; consequently, it is seldom used in physical therapy. Cold may be applied locally using an ice bag, a cold pack, or volatile fluids (eg,ethyl chloride, vapocoolant spray), which cool by evaporation. Spread of cold on the skin depends on the thickness of the epidermis, underlying fat and muscle, water content of the tissue, and rate of blood flow. Care must be taken to avoid tissue damage and hypothermia. Cold should not be applied over poorly perfused areas. 