Biofeedback is a treatment used by physical therapists to help patients see what muscles they are using and how they are using them. There are different kinds of biofeedback. For example, holding a tiny thermometer in the hand can record skin temperature. By thinking about breathing and imagining a warm place, it is possible to increase the blood flow to the fingers. This increases the temperature of the skin, and the thermometer records the increase on a computer screen.
Likewise, muscle activity can be measured with electrodes placed on the skin. These record the electrical impulses of the muscles when they contract. By watching signals on the computer screen or hearing signals, it is possible to increase or decrease muscle contractions. This form of biofeedback is called electromyographic biofeedback.
Biofeedback treatment is used to help people improve their ability to control their own muscles. Once the electrodes are in place, the therapist will teach the patient how to contract and hold one muscle while relaxing another. When the muscles function properly, the patella moves normally, and pain is reduced or eliminated.