The Effects of Intramuscular Electrical Stimulation on Clinical and Sonographic Parameters in the People With Trigger Points: A Case Series Study

Myofascial pain syndrome (MPS) is a clinical disorder with a prevalence of 85%. It is characterized by the presence of trigger points, and all people experience it at least once in their lives. Different physiotherapy and medical methods are used to manage MPS. Intramuscular electrical stimulation (IMES) is a relatively new treatment option for MPS. This study aims to examine the effect of IMES on clinical and ultrasound imaging parameters related to trigger points in patients with MPS.

This is a case series clinical trial. Twelve participants with trigger points in their upper trapezius muscles participated in this study. They were treated three times per week with IMES. Before and after the intervention, pain and cervical spine range of motion (ROM) were measured with the visual analog scale and goniometry. Ultrasonic parameters (longitudinal diameter and the area of trigger points, and the thickness of the upper trapezius muscle) were assessed with B-mode ultrasound imaging technique. The pre-test and post-test values were compared using the paired t-test. The significance level was set at 0.05.

After three sessions of IMES, pain and cervical spine ROM improved significantly (P<0.05). All ultrasound imaging parameters, including trigger points’ longitudinal diameter and area and upper trapezius muscle thickness, decreased significantly compared to baseline (P<0.05).

IMES seems to have promising effects on clinical and ultrasound imaging parameters of patients with MPS. Further studies with larger sample sizes are recommended to investigate the long-term effects of IMES with the inclusion of a matched control group.