Date of Award


Document Type

Scholarly Project

Degree Name

Master of Physician Assistant Studies (MPAS)


Physician Assistant Studies

First Advisor

Jeanie McHugo


Myofascial pain syndrome; Trigger point; Trigger point injections; Dry needling; Local anesthetic; Botulinum toxin-A; Local twitch response; Ultrasonography


Myofascial pain syndrome (MPS) is one of the most common musculoskeletal conditions characterized by tight bands of fascia and muscle fibers known as myofascial trigger points (MTrP). Empirical evidence suggests that deactivation of MTrP’s is best accomplished with invasive needling therapy such as dry needling, trigger point injections, and Botulinum toxin-A (BTX-A) injections. The objective of this systemic review is to compare the effectiveness of various needling therapies on pain intensity and determine if ultrasound guidance and obtaining a local twitch response (LTR) improves clinical outcomes. A comprehensive search of five databases including PubMed, Science Direct, Google Scholar, Cochran, and CINHAL was completed. Keywords included myofascial pain syndrome, trigger point, trigger point injections, dry needling, local anesthetic, botulinum toxin-A, local twitch response, and ultrasonography Fifteen studies were included in this systemic review with inconsistent results. All three therapies were shown to be effective for decreasing pain intensity associated with MPS. Research suggests that dry needling and local anesthetics have similar short-term efficacy and are best indicated for treating regions of the shoulder and cervical muscles. Analgesic effects of BTX-A are delayed but may be longer-lasting, especially when treating regions of highly active muscles. Ultrasound guidance improves clinical outcomes by reducing localization errors and adverse events. Obtaining an LTR is inconsistently correlated with short-term pain relief but is not dependent upon it.