Myofascial origins of low back pain. 1. Principles of diagnosis and treatment.

Myofascial trigger points (TPs) are frequently overlooked sources of acute and chronic low back pain. An active myofascial TP is suspected by its focal tenderness to palpation and by restricted stretch range of motion. The restricted lengthening of the muscle is due to the tense band of muscle fibers in which the TP is located. The presence of a TP is confirmed by a local twitch response and by reproduction of its known pattern of referred pain, which matches the distribution of the patient's pain. Only an active TP causes a clinical pain complaint; a latent TP does not. The pain can be relieved by the stretch-and-spray procedure, ischemic compression, or precise injection of the TP with procaine solution. Relief is usually long lasting only if mechanical and systemic perpetuating factors are corrected.