The client learns to decrease muscle tension for example, or in the case of asymmetry increase or decrease the abnormal muscle tension as appropriate. The principles of biofeedback depend upon being able to measure a physiological signal (in this case EMG from a muscle of interest) then make the state of this signal (feedback) available to the client in a simple and meaningful manner. Asymmetry in which one side of the back or hamstring muscles has normal EMG levels whils tthe other side has abnormally high or low levels.Unusually high muscle tension levels - which is the most frequently seen abnormality.Unusually low muscle tension levels that are perhaps due to nerve damage and the resulting muscle atrophy.In the case of low back pain, experience suggests three possible muscle tension abnormalities The NeXus range of biofeedback systems are all capable of plug and play interventions in this application area. More EMG equals more muscle tension - less EMG equals less muscle tension. As muscle contraction occurs some electrical energy leaves the muscle and migrates through surrounding tissue to the skin surface where it can be detected. Each muscle consists of many muscle fibers with motor neurons that are electrically connected to higher levels of the nervous system. The EMG instrumentation picks up the weak electrical signals generated when a muscle contracts. Surface EMG is a non-invasive way of monitoring tension in a muscle group by using surface electrodes. The surface EMG also shows differences based on the underlying cause of the back pain.

Some research on low back pain shows significant surface EMG (electromyographic) activity differences between persons with back pain compared with a control group of persons without pain.

Emg lower back