Muscles electrical activity during dry needling of the latent trigger points

Background: The effectiveness of dry needling (DN) is still under scrutiny within the medical community. Consequently, ongoing efforts are being made to enhance objectivity. Aim of the study: The goal was to demonstrate the distinct bioelectrical activity in the thigh muscles resulting from the dry needling of trigger points in the gluteus minimus muscle. Material and methods: Four healthy asymptomat-ic subjects were examined, with two of them presenting latent trigger points (LTrPs) accompanied by referred pain (RP), while the other two did not exhibit LTrPs. All participants underwent 2 x 5 minutes of fast-in-fast-out dry needling (DN) of the gluteus minimus muscle, monitored by super-ficial electromyography (sEMG). Results: The analyzed sEMG reveals the bioelectrical activity of the specific muscles where patients experienced referred pain (RP). In the RP-affected area, there was a notable rise in mean bioelectrical activity, ranging from 117% to 338%, accompanied by an increase in mean amplitude from 3.6 V to 26 V. Conversely, in patients without RP, the mean amplitude only ranged from 0.2 V to 2.2 V, despite the presence of severe pain associated with dry needling (DN).Conclusions: For the first time, heightened bioelectrical activity in a specific muscle group of the thigh, resulting from dry needling of the gluteus minimus latent trigger point (LTrP) that induced referred pain, has been documented.