Low Back Pain
The remaining common chronic pain that is relatively responsive to EMG biofeedback is that of the low back. Low back pain is an extremely common complaint; Arena and Blanchard (1996) cite the statistic that up to 60 to 80% of the population will experience this pain at some point; this has a large cost in terms of lost job productivity.
Causes of Low Back Pain
Many individuals with chronic low back pain have no discernable physical cause, which explains the popularity of more alternative remedies. However, the two most common theories attribute pain to muscle tension, due either to ineffective coping with stress or to a biomechanical asymmetry in the left and right sides of the back. Abnormal biomechanics may cause the overuse of muscles on only one side, and this constant tension leads to pain.
Current Research
Research has found conflicting results in this area, much like tension headache research. Some studies have found that chronic pain patients are hypersensitive to stress and misperceive their muscular tension (see Flor, Furst, & Birbaumer, 1999), thereby responding better to biofeedback than to relaxation (Donaldson, Romney, Donaldson, & Skubick, 1994). However, others have found no difference between the effects of biofeedback, relaxation training or cognitive behavioral therapy in the treatment of low back pain (Newton-John, Spence, & Schotte, 1995).
The research on biofeedback therapy on its own is deemed so methodologically flawed that there is not sufficient evidence to use that treatment unaccompanied. It is usually combined with medication, physical exercises, neurosurgery, and other treatments to maximize its success. Also, EMG biofeedback to treat low back pain is often performed with the forehead muscles, since that appears to be just as effective as targeting the back and leg muscles (Arena & Blanchard, 1996).
As with the other chronic musculoskeletal pain disorders, subjective improvement in low back pain does not seem to have any relation to progress in biofeedback. Nigl (1984) reports that although participants in one study decreased their muscle contractions through EMG biofeedback therapy, they returned to baseline after the research concluded. However, they continued reporting decreased subjective pain levels. Again, it appears that improvement depends on cognitive factors such as self-efficacy, which implies that cognitive treatments may be just as helpful as biofeedback.