The most effective heat therapy products are the ones that can maintain their heat at the proper temperature. "Warm" is the proper temperature. Patients should not have their heat source be hot to the point of burning the skin. The desired effect is for the heat to penetrate down into the muscles. Simply increasing the temperature of the skin will do little to decrease discomfort.
In many instances, the longer the heat is applied, the better. The duration that one needs to apply the heat, though, is based on the type of and/or magnitude of the injury. For very minor back tension, short amounts of heat therapy may be sufficient (such as 15 to 20 minutes). For more intense injuries, longer sessions of heat may be more beneficial (such as 30 minutes to 2 hours, or more).
Types of Heat Therapy
Two options for heat therapy include moist heat and dry heat.
- Dry heat, such as electric heating pads and saunas, draw out moisture from the body and may leave the skin dehydrated. However, some people feel that dry heat is the easiest to apply and feels the best.
- Moist heat, such as hot baths, steamed towels or moist heating packs can aid in the heat’s penetration into the muscles, and some people feel that moist heat provides better pain relief.
A specific type of heat therapy may feel better for one person than for another, and it may require some experimentation to figure out which one works best. There are many different manners for heat to be applied to the lower back. Some common options include:
- Hot water bottle - tends to stay warm for 20 to 30 minutes.
- Electric heating pad - maintains a constant level of heat as long as it is plugged in.
- Heated gel packs - may be microwaved, or sometimes heated in water, and tend to say warm for about 30 minutes. Certain types of gel packs provide moist heat, which some people prefer.
- Heat wraps - wraps around the lower back and waist and may be worn against the skin under clothing, providing convenience and several hours of low level of heat application.
- Hot bath, hot tub, sauna, steam bath - tend to stimulate general feelings of comfort and relaxation that may help reduce muscle spasm and pain. A whirlpool jet directed at the lower back may provide the added benefit of a light massage.
Finally, it is important to use enough insulation between the heat source and the skin to avoid overheating or burning the skin.
When Heat Therapy Is Not an Option
Please note that heat should not be used in certain circumstances. For example, if the lower back is swollen or bruised, heat should not be used. Patients should consult doctors if they have heart disease or hypertension. Heat application is also not suitable in the following cases:
- Deep vein thrombosis
- Peripheral vascular disease
- Open wound
- Severe cognitive impairment
In general, if the injured area is swollen or bruised it is better to apply ice or a cold pack to reduce the swelling.
In summary, heat therapy is an easy and inexpensive option to provide relief from many forms of lower back pain. It may be used alone or in conjunction with other therapies. Because it is so simple, it is often overlooked and physicians may forget to mention it, but heat therapy used in the right way can be a valuable part of many lower back pain treatment programs.