Moist heat -- also called superficial heat -- is a physical therapy modality used to control pain, speed healing, relax muscles and increase range of motion. In a moist heat treatment, a hot pack is placed on the tight or painful area and left there while you relax for about 10 or 15 minutes.
Moist heat packs used in physical therapy clinics are made of bentonite covered in canvas. The packs are stored in very hot (158 to 167 degree F) water. When the moist heat packs are prepared for use, they are placed in towels and/or special wraps. This not only help prevent burns, it also slows down cooling, giving you more time to enjoy and benefit from your moist heat treatment.
Moist Heat for Pain Control
Moist heat may control your pain by blocking pain signals from being transmitted. Application of superficial heat may also help reduce pain by relaxing muscle spasm and enhancing healing. Moist heat should only be used for chronic or sub-acute back or neck pain. If you put a hot pack on an acute injury, you risk increased swelling or bleeding, which may aggravate the area and cause more pain.
Moist Heat Speeds Healing
Put a hot pack on an injured or tight area of your back, and you'll likely increase circulation. Increased circulation speeds the delivery of blood, and therefore oxygen and nutrients. It also accelerates the removal of waste products.
Another way moist heat helps the healing process is by increasing enzyme activity. This raises your metabolic rate. It also helps oxygen release from the hemoglobin molecules and into your tissues, where it helps with repair.
Moist Heat and Flexibility
Moist heat relaxes muscles and other soft tissue. Your therapist may also guide you in using stretching with moist heat. Stretching during or after your moist heat treatment may result in longer-lasting flexibility improvements. It's also less painful.