J Clin Med. 2021 Nov 25;10(23):5527. doi: 10.3390/jcm10235527.
This study aimed to investigate the efficacy of concentric, eccentric, and isometric exercise protocols on the postneedling soreness (PNS) after the dry needling (DN) of latent myofascial trigger points (MTrP) in the medial gastrocnemius muscle. A randomized clinical trial was carried out. Volunteers, ≥18 years old, with a latent MTrP in the medial gastrocnemius muscle were included. Subjects with contraindications to DN, active MTrPs, and/or other treatments in MTrPs in the 3 months prior to recruitment were excluded. A total of 69 participants were randomly allocated to four groups, where post-DN intervention consisted of an eccentric, concentric, or isometric exercise, or no exercise, and they were assessed for PNS intensity (visual analog scale (pVAS)), pressure pain threshold (PPT, analog algometer), pain intensity (nVAS), and local twitch responses (LTRs) during DN, as well as demographics and anthropometrics. The mixed-model analyses of variance showed significant interaction between time and pVAS, and between time and PPT (p < 0.001). While the multivariate test confirmed that PNS and PPT improved over time within each group, specifically between 6-12 h post-intervention, the post hoc analyses did not show significant differences between groups. The mixed-model analyses of covariance showed a significant nVAS effect (p < 0.01) on PNS decrease, and some effect of the LTRs (p < 0.01) and sex (p = 0.08) on PPT changes. All groups improved PNS and PPT, but none of them showed a greater improvement above the others. The most dramatic decrease was observed between 6-12 h post-exercise, although concentric and eccentric exercise had an effect immediately after the intervention. Between all potential modifiers, pain during DN significantly influenced PNS progression, while LTRs and sex seemed to determine PPT course over time.