Short-term effect of frequency specific intramuscular electrical stimulation on post dry needling soreness of upper fibers of trapezius: A randomized controlled trial

Objectives: The purpose of this study was to compare the effect of frequency specific intramuscular electrical stimulation on post trigger point dry needling soreness. Background: Dry needling (DN) with intramuscular electrical stimulation (DN/IMES) has been shown to be effective in reducing post needling soreness. The effect of frequency specific intramuscular electrical stimulation on post needling soreness has not been studied abundantly, but initial results are favorable. This study investigated the effect of frequency specific intramuscular electrical stimulation on post needling soreness. Methods: A convenience sample of 45 (alpha = 0.05, power = 95%) subjects was recruited for this study and randomly assigned to DN (n = 15), DN/IMES [f-2Hz] (n = 15) and DN/IMES [f-100Hz] (n = 15) groups. Pain Pressure Threshold (PPT) and Numeric Pain Rating Scale (NPRS) were measured before and 24 hours after the intervention. Result: Both DN/IMES [f-2Hz and 100 Hz] groups showed statistically significant improvement in NPRS (p = 0.001 and 0.00005, respectively) and PPT (p = 0.004 and 0.0002, respectively). No statistically significant changes were observed in DN group in NPRS (p = 0.726) and PPT (p = 0.238). Conclusion: Both dry needling with Intramuscular electrical stimulation (DN/IMES [f-2Hz and 100Hz]) groups demonstrated statistically significant improvement in soreness as compared to DN group, but DN/IMES [f-100 Hz] group showed more significant improvement as compared to DN/IMES [f-2 Hz] group in reducing post needling soreness.