special subjects
Rehabilitative Measures for Treatment of Pain and Inflammation
Heat
Heat provides temporary relief in subacute and chronic traumatic and inflammatory disorders (eg, sprains, strains, fibrositis, tenosynovitis, muscle spasm, myositis, back pain, whiplash injuries, various forms of arthritis, arthralgia, neuralgia). Heat increases blood flow and the extensibility of connective tissue; heat also decreases joint stiffness, pain, and muscle spasm and helps relieve inflammation, edema, and exudates. Heat application may be superficial (infrared heat, hot packs, paraffin bath, hydrotherapy) or deep (ultrasound). Intensity and duration of the physiologic effects depend mainly on tissue temperature, rate of temperature elevation, and area treated. Infrared heatis applied with a heat lamp, usually for 20 minutes/day. Contraindications include implanted metal device and impaired skin sensation (particularly to temperature and pain). Precautions must be taken to avoid burns. Hot packsare cotton cloth containers filled with silicate gel; they are boiled in water or warmed in a microwave oven, then applied to the skin. The packs must not be too hot. Wrapping the packs in several layers of towels helps protect the skin from burns. Contraindications are the same as those for infrared heat. For aparaffin bath,the affected area is dipped in, immersed in, or painted with melted wax that has been heated to 49°C. The heat can be retained by wrapping the affected area with towels for 20 minutes. Paraffin is usually applied to small joints—typically, by dipping or immersion for a hand and by painting for a knee or an elbow. Paraffin should not be applied to open wounds or used on patients allergic to it. A paraffin bath is particularly useful for hand osteoarthritis. Hydrotherapymay be used to enhance wound healing. Agitated warm water stimulates blood flow and debrides burns and wounds. This treatment is often given in a Hubbard tank (a large industrial whirlpool) with water heated to 35.5 to 37.7°C. Total immersion in water heated to 37.7 to 40°C may also help relax muscles and relieve pain. Hydrotherapy is particularly useful with range-of-motion exercises. Diathermyis therapeutic heating of tissues using oscillating high-frequency electromagnetic fields, either short-wave or microwave. These modalities do not seem superior to simpler forms of heating and are now seldom used. 