Table 1.

Comparing Travell and Simons’ Contributions to the Contemporary Understanding of Myofascial Trigger Points

Understanding of MTrPs based on Travell and Simons’ work	Contemporary understanding of MTrPs based on scientific evidence
MTrP Characteristics A systematic description of physical and electrodiagnostic findings: • Defined MTrP as “a hyperirritable locus within a taut band of skeletal muscle . . . [that] is painful on compression and can evoke characteristic referred pain and autonomic phenomena” • Differentiated active from latent MTrPs • Codified criteria for identifying MTrPs in the evaluation of pain • Utilized electrodiagnostic studies to demonstrate abnormal activity, indicating involvement of the neuromuscular junction	MTrP Characteristics Objective measures of abnormal physical findings suggesting MTrP pathophysiology: • Biochemical findings indicate local and remote inflammation, and local acidic milieu • Biochemical and physical findings implicate local sensitization • Oxygenation studies indicate local regions of hypoxia • Imaging studies indicate local regions of muscle stiffness • Evidence implicating abnormalities of the myofascial neighborhood beyond the MTrP
Relation to MPS MTrP causes MPS symptomatology: • MTrP associates with focal pain and hyperirritability • MTrP presents with pain radiation • MTrP perturbation produces local twitch response	Relation to MPS Relationship between MTrP and MPS has not yet been determined: • Patients may have MPS without MTrPs, and MTrPs without MPS • MTrP may or may not present with pain radiation • MTrP perturbation does not always produce local twitch response
Clinical Evaluation Clinical case series propose tentative link between symptoms and physical findings: • A specific collection of symptoms is associated with MTrPs including regional pain, decreased flexibility, and clinical signs of allodynia and hyperalgesia • Stereotypical patterns of referred pain are associated with MTrPs in different muscles	Clinical Evaluation Clinical studies and trials establish link between symptoms and physical findings: • Mechanisms of muscle nociception, sensitization, and pain have been well documented • Biochemical studies link painful MTrPs with muscle nociception, sensitization, and pain
Treatment Treatments target MTrPs to reduce pain: • Spray and stretch • Deep massage • Anesthetic injections • Pharmacological agents	Treatment Treatments target MTrP to reduce pain and improve symptoms and function: • Manual manipulation • Dry needling • Transcutaneous electrical nerve stimulation • Ultrasound
Outcome Measures Treatment of MTrP leads to: • Improvement of pain • Increased flexibility (anecdotally)	Outcome Measures Treatment of MTrP leads to: • Improvement of pain • Decreased tenderness • Increased range of motion • Improvement of quality of life