Biofeedback

The idea behind biofeedback is as simple as stepping onto a bathroom scale -- it gives you information about your body that you are unaware of. This information allows you to control your body. For example, if you notice that your weight is steadily rising, you can try eliminating desserts or other high calorie foods until your weight starts dropping. Awareness of your precise weight helps you reduce it to what you want.

It is amazing what body functions we can control if we have sufficient feedback. For example, people can learn to control heart rate, blood pressure, skin temperature, and so on if they are given information about these processes. If you hook yourself up to a simple meter that measures your blood pressure, you can learn to control it at will. The meter gives you awareness of your blood pressure, and this awareness allows you to learn how to control it.

Many people ask how we can learn to control our bodies this way. The process is not exactly clear, but compare it to learning something simple like raising your arm over your head. Can you say how you do that? Most people say, "I just do it, I can't explain how." One explanation is that we learned how to do it when we were infants. Infants develop an awareness of the position of their arms, and then by trying various things they learn to move their arms to specific locations. Likewise, when you are hooked up to a blood pressure meter, you try various things and you see what moves the needle. You get better and better at it with practice, even though you can't explain exactly how you do it.

What has this got to do with pain control? Underlying any pain is a physiological state that causes the pain, either directly or indirectly. For example, tension headache is directly caused by muscle tension. If you learn to control this muscle tension, you can eliminate the headache. What causes the muscle tension? There are many possible causes, but a frequent one is "stress". If we had a "stress-meter" we could learn to control our stress level, too.

Biofeedback has many applications in pain relief. It has been used for tension, migraine, and cluster headache, back and shoulder pain, TMJ (temporomandibular joint syndrome, or jaw pain), and chronic pain in general.

One popular type of biofeedback uses the electromyogram, or EMG, which measures muscle tension. Several types of pain involve muscle tension, either as a primary cause or a contributing factor. We can use the EMG to monitor muscle tension and thus learn to control it. This benefits problems such as tension headache and back pain. With tension headache, electrodes are placed on the forehead or on the neck and shoulders, and the subject learns to relax these muscles. For lower back pain, electrodes are placed on the muscles of the lower back muscles or on the leg biceps, the muscles on the back of the thighs. With both tension headache and backache, muscle tension can be a direct cause of pain, or it may aggravate any existing problem. For example, muscle tension alone can cause cramping and pain. If a person has a disk problem in their lower back, muscle tension can increase the pressure on the injured area, thus increasing the pain. Even an imbalance of muscle tension from one side of the body to another can aggravate an existing problem. EMG biofeedback can be a very effective treatment for these problems.

Another popular type of biofeedback involves measuring skin temperature. A common treatment is to place a temperature sensor on the subject's finger or hand, and the subject learns to warm their hand. This has been used as an effective treatment for migraine and cluster headache, and also for other types of chronic pain. How does this work? When a person is stressed or in pain, their body reacts with a fight or flight response that involves increased muscle tension, increased heart rate and respiration, hormonal changes, increased blood flow to the head, and decreased blood flow to the extremities. When your body is prepared to fight or to run away, blood flow is increased to your brain, heart and large muscles to help you move, while blood flow is reduced to the hands and feet to avoid losing blood to an injury. The increase in blood flow to the head makes the head warm, while the reduction of blood flow to the extremities makes them cool off. This reaction is so common that it has become part of our popular language. For example, we say "He is a hot head" to indicate that a person is angry and ready for a fight, and we say "He had cold feet" to indicate that someone is afraid and wanting to run away.

In previous lessons we have discussed the SEAT of pain -- the fact that pain is composed of Sensation, Emotion, Attention, and Thought components. The fight or flight "defensive reflex" increases pain of all kinds, because the fight or flight reaction IS the Emotional component of pain. Remember that any component of pain can make all the others worse. The Emotional component can increase the Sensation, Attention, and Thought components of pain. If we can reduce the Emotional component, we can reduce pain in general. Some types of pain are also directly affected by the fight or flight response. For example, increased blood flow to the head has been implicated as a causal factor in migraine headache.

When subjects learn to warm their hands, they are counteracting the fight or flight reaction, and thus are diminishing a major component of pain. At the same time they are counteracting any direct cause of pain, as in migraine headache, for example. Biofeedback of skin temperature is an important technique in helping people deal with various problems, including anxiety, headache, backache, and other pain. It is also used in relaxation training, which is often employed in pain management programs. Consider one of the most intractable sources of pain, daily severe headache. Recent research has shown that among conventional therapies, the best treatment is a combination of relaxation and biofeedback.