The importance of the local twitch response during needling interventions in spinal pain associated with myofascial trigger points: a systematic review and meta-analysis

Objective: To compare the clinical effects of needling interventions eliciting local twitch responses (LTRs) versus needling without eliciting LTRs when applied to muscle trigger points (TrPs) associated with spinal pain of musculoskeletal origin.Databases and data treatment: Electronic databases were searched for randomized or non-randomized clinical trials where one group received needling intervention where LTRs were elicited and was compared with another group receiving the same intervention without elicitation of LTRs in spinal pain disorders associated with TrPs. Outcomes included pain intensity, pain-related disability, and pressure pain thresholds. The risk of bias (RoB) was assessed using the Cochrane risk of bias tool or ROBINS-I tool, methodological quality was assessed with the PEDro score, and quality of evidence was evaluated using the GRADE approach.Results: Six trials were included. The application of a needling intervention eliciting LTRs was associated with a significant reduction in pain intensity immediately after treatment (mean difference (MD): −2.03 points, 95% confidence interval (CI): −3.77 to −0.29; standardized MD (SMD): −1.35, 95% CI: −2.32 to −0.38, p= 0.02) when compared to the same needling intervention without elicitation of LTRs. No effect at short-term follow-up (MD: −0.20 points, 95% CI: −1.46 to 1.06, p= 0.75) was observed. No significant differences based on elicitation or non-elicitation of LTRs were found in related disability (SMD: −0.05, 95% CI: −0.41 to 0.30, p= 0.77) or pressure pain thresholds (MD: 23.39 kPa, 95% CI: −13.68 to 60.47, p= 0.22).Discussion: Low-level evidence suggests an immediate effect of obtaining LTRs during needling interventions on pain intensity, with no significant effects on related disability or pressure pain sensitivity in spinal pain disorders associated with muscle TrPs.Registration number: OSF Registry—https://doi.org/10.17605/OSF.IO/5ZX9N