Given the fact the there is still significant deniability within the wider medical community regarding the existence of myofascial trigger points (MTrP), I am always interested to learn of further physical evidence to back up our clinical assessment findings.
Although the ability to image MTrP and taut band on ultrasound is not new, recently I was fortunate to view not only a still frame but a video clip of a needle penetrating a taut band an eliciting the local twitch response. The vigorous response from the muscle when the MTrP was targeted directly would suggest a level of reactive dysfunction within that particular portion of muscle which would be difficult to dispute, especially if the patients familiar pain was reproduced at the same time. Further ultrasound findings have included hypoechogenicity, alterations on local muscle tension and muscle entropy (Shah et al, 2008).
Furthermore, vascular flow studies by Sidkar et al (2009), have shown vasospasm within the MTrP with raised systolic and diastolic pressures, decreased pH and ischaemia which may support the etiological energy crisis hypothesis
Further studies by Shah et al (2008) have shown that the have shown the MTrP contains increased quantities of nociceptive sensitising substances such as CGRP, bradykinin and substance P which may explain the equisite tenderness to palpation.
In a clinical setting we are reliant on identifying the taut band and the exquisite tender point which refers pain through a characteristic referral pattern. Pain referral must be noted as the most cardinal feature, without which the reliability of clinical assessment findings seems to fall short.
Simon.
