[clarification needed] Accordingly, a formal acceptance of myofascial "knots" as an identifiable source of pain is more common among bodyworkers, physical therapists, chiropractors, and osteopathic practitioners.

Nonetheless, the concept of trigger points provides a framework which may be used to help address certain musculoskeletal pain.

There is variation in the methodology for diagnosis of trigger points and a dearth of theory to explain how they arise and why they produce specific patterns of referred pain.

The integrated hypothesis theory states that trigger points form from excessive release of acetylcholine which produces sustained depolarization of muscle fibers.

Indeed, the trigger point has an abnormal biochemical composition with elevated concentrations of acetylcholine, noradrenaline and serotonin and a lower pH.

Many trigger points have pain patterns that overlap, and some create reciprocal cyclic relationships that need to be treated extensively to remove them.

[citation needed] Practitioners do not agree on what constitutes a trigger point, but the assessment typically considers symptoms, pain patterns and manual palpation.

[citation needed] A 2007 review of diagnostic criteria used in studies of trigger points concluded that there is as yet limited consensus on case definition in respect of MTrP pain syndrome.

Until reliable diagnostic criteria have been established, there is a need for greater transparency in research papers on how a case of MTrP pain syndrome is defined, and claims for effective interventions in treating the condition should be viewed with caution.

[6] Since the early 2000s several research studies have been conducted to determine if there was a way to visualize myofascial trigger points using tools such as ultrasound imaging and magnetic resonance elastography.

[12] Myofascial pain syndrome is a focal hyperirritability in muscle that can strongly modulate central nervous system functions.

Referred pain from trigger points mimics the symptoms of a very long list of common maladies, but physicians, in weighing all the possible causes for a given condition, rarely consider a myofascial source.

[14] Therapists may use myotherapy (deep pressure as in Bonnie Prudden's approach, massage or tapotement as in Dr. Griner's approach), mechanical vibration, pulsed ultrasound, electrostimulation,[15] ischemic compression, trigger-point-injection (see below), dry-needling, "spray-and-stretch" using a cooling spray (vapocoolant), low-level laser therapy and stretching techniques that invoke reciprocal inhibition within the musculoskeletal system.

[citation needed] Physical exercise aimed at controlling posture, stretching, and proprioception have all been studied with no conclusive results.

[16] Researchers of evidence-based medicine concluded as of 2001 that evidence for the usefulness of trigger points in the diagnosis of fibromyalgia is thin.

[citation needed] Despite the concerns about long acting agents,[1] a mixture of lidocaine and bupivacaine (Marcaine) is often used.

[citation needed] In 1979, a study by Czech physician Karl Lewit reported that dry needling had the same success rate as anesthetic injections for the treatment of trigger points.

[citation needed] Studies have shown a moderate level of evidence for manual therapy for short-term relief in the treatment of myofascial trigger points.

[26] In a June 2000 review, Chang-Zern Hong correlates the MTrP "tender points" to acupunctural "ah shi" ("Oh Yes!")