Dry needling has established its role within the rehabilitation toolkit primarily through the mechanical action of the needle, generating a transient window of altered tissue and neural input. Electrical dry needling (EDN) introduces a different inquiry: what are the effects when the needle concurrently functions as a conduit for a controlled electrical current, and does this modification influence clinical outcomes in a manner that justifies the additional complexity, expense, and required training? For clinicians addressing knee osteoarthritis, plantar fasciitis, subacromial pain, cervicogenic headache, or chronic myofascial pain, this is not merely an academic question; it directly informs daily treatment planning. Based on current musculoskeletal literature, the consensus suggests that EDN appears to provide clinically significant benefits beyond those achieved with needling and manual or exercise-based therapies alone in several well-investigated conditions.^8-17 Nevertheless, the relationship between mechanism and dosage remains incompletely understood, and considering EDN as a single, fixed “setting” misrepresents both the evidence and the underlying neurobiological principles.

Why the Needle Alone Isn’t the Whole Story: Electrical Dry Needling

A useful starting point is recognizing that manual needle insertion and electrically stimulated needling are not simply two intensities of the same intervention; they appear to engage at least partially distinct mechanisms. Schliessbach et al.randomized subjects to non-stimulated acupuncture needling, non-penetrating sham needling, and a cold-pressor–induced diffuse noxious inhibitory control (DNIC) condition, and found no significant difference in pressure pain threshold between real and sham needle insertion, while the DNIC condition produced a substantially larger analgesic effect.¹ That finding matters clinically: it suggests that needle insertion alone does not reliably recruit the same descending, diffuse inhibitory pathways that a stronger conditioning stimulus, such as electrical stimulation delivered at an intensity the patient can feel, appears to access. Diffuse noxious inhibitory control itself, now more often discussed under the broader label of conditioned pain modulation, reflects a spinal-and-supraspinal gating phenomenon in which a remote noxious or strongly conditioning input suppresses nociceptive transmission elsewhere in the body, a mechanism well characterized in healthy adults of both sexes.² Electrical dry needling, by delivering a sustained, quantifiable stimulus through the needle itself, is positioned to engage this gating mechanism and descending control mechanisms more consistently over time than passive needle placement or brief mechanical pistoning.

The analgesic and anti-inflammatory effects associated with electrically stimulated needling are not attributable to a single pathway. Zhang and colleagues’ comprehensive review of the mechanisms of acupuncture and electroacupuncture in persistent pain delineates a multilevel model encompassing peripheral, spinal, and supraspinal systems. It is noted that electroacupuncture activates a variety of bioactive substances, including opioids that desensitize peripheral nociceptors and reduce pro-inflammatory cytokines both peripherally and in the spinal cord. Additionally, it involves serotonin and norepinephrine, which decrease phosphorylation of NMDA receptor subunits in the spinal cord. Furthermore, inhibition of inflammatory and neuropathic pain appears to be more efficacious at stimulation frequencies of 2–10 Hz compared to 100 Hz.³

At the peripheral and cellular level, multiple mechanistic studies converge on an anti-inflammatory, pro-resolving effect of electrically stimulated needling in inflamed tissue. Su et al. demonstrated that electroacupuncture applied to inflamed rat skin reduced the expression of the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α through activation of peripheral cannabinoid CB2 receptors, an effect that was reversed by a CB2 antagonist and reproduced with a selective CB2 agonist.⁴ Vieira and colleagues identified a related yet distinct pathway, demonstrating that the antihyperalgesic effect of electroacupuncture in an inflamed paw model is dependent on the peripheral annexin A1–formyl peptide receptor 2/ALX pathway working synergistically with opioid receptor signaling. This finding aligns with a true pro-resolving inflammatory mechanism rather than mere symptomatic masking.⁵ A separate study conducted by Zhang et al. discovered that the antihyperalgesic effect of electroacupuncture in a chronic inflammatory pain model was partly mediated by increased levels of adenosine and the suppression of substance P and its subsequent inflammatory markers in the dorsal root ganglion. Furthermore, the analgesic effect was inhibited by antagonism of adenosine receptors.⁶ In summary, this peripheral evidence base, although predominantly preclinical, provides a biologically plausible explanation for why electrically stimulated local tissue responses might surpass mechanical stimulation alone, especially in conditions characterized by an active peripheral inflammatory component, such as knee osteoarthritis or plantar fasciitis. At the supraspinal and systemic levels, the frequency of stimulation appears to significantly influence the underlying mechanisms, although the clinical implications of this observation remain uncertain. In an animal model, Cheng et al. stimulated goats with electroacupuncture at various frequencies 0, 2, 40, 60, 80, and 100 Hz and discovered that low frequencies (2 Hz) predominantly enhanced the release of met-enkephalin and β-endorphin across multiple analgesia-related central nervous system nuclei. Conversely, high frequencies facilitated the release of dynorphin-A, and a frequency of 60 Hz yielded the most substantial overall increase in pain threshold by concurrently activating all three opioid peptide families..⁷ This frequency-dependent pattern of opioid release is among the most reliably replicated findings within the broader electroacupuncture literature and serves as the physiological foundation for employing different stimulation frequencies to achieve various clinical objectives. However, it is important to clarify that this particular study was conducted on ruminants rather than humans. Moreover, the effects associated with specific frequencies do not always translate seamlessly into comparable clinical benefits, as demonstrated by the musculoskeletal trials discussed below.

The strongest and most consistent clinical evidence for EDN in orthopedic and sports medicine populations comes from a series of multicenter randomized trials, predominantly from Dunning, Fernández-de-las-Peñas, and colleagues, that added periosteal or perineural electrical dry needling to standard manual therapy and exercise programs.

In cases of knee osteoarthritis, a total of 242 participants were randomly assigned to undergo a six-week regimen of electrical dry needling combined with manual therapy and exercise, or to receive only manual therapy and exercise. The group receiving electrical dry needling demonstrated significantly greater improvement in disability scores assessed by WOMAC at three months, was 1.7 times more likely to discontinue pain medication, and exhibited a substantially higher proportion of patients achieving a successful outcome according to the global rating of change (75% compared to 18%). Additionally, large effect sizes (standardized mean differences greater than 0.82) consistently favored the electrical dry needling group across all evaluated measures outcomes.⁸ A recent study conducted by Lin et al. specifically isolated the waveform variable within EDN, involving 138 patients with knee osteoarthritis who were randomly assigned to receive a single intra-articular corticosteroid injection followed by sham stimulation, dense-disperse wave, or continuous wave electrical dry needling. Both active waveforms demonstrated superior performance compared to sham in terms of pain and WOMAC scores at all follow-up intervals up to 12 weeks, with the dense-disperse waveform exhibiting a slight additional benefit over the continuous wave at the later time points.⁹ A systematic review conducted in 2025 regarding periosteal EDN for knee osteoarthritis concluded that four out of six eligible studies exhibited significant enhancements in pain and mobility. However, it explicitly stated that additional large-scale randomized trials are necessary before EDN can be regarded as a validated standalone therapy rather than a promising adjunct.¹⁰

A comparable pattern extends beyond the knee. In cases of plantar fasciitis, 111 participants receiving electrical dry needling (EDN) in conjunction with manual therapy, exercise, and ultrasound exhibited significantly greater improvements in first-step morning pain, resting pain, and multiple functional measures compared to those undergoing the same regimen without EDN. The effect sizes ranged from medium to large (0.53–0.85), with 78% achieving a successful outcome at three months, contrasted with 21% in the control group. In the context of subacromial pain syndrome, the addition of electrical dry needling to thoracic thrust manipulation resulted in significantly greater reductions in pain and disability than non-thrust mobilization combined with exercise, with large effect sizes favoring the manipulation-plus-EDN cohort. For cervicogenic headache, spinal manipulation combined with perineural electrical dry needling led to significantly greater reductions in headache intensity, frequency, and disability compared to mobilization and exercise, with 77% of the EDN group attaining a successful outcome against 15% in the comparison group. Additionally, nearly two-thirds of participants discontinued headache medication entirely by three months.¹³ In cases of lumbar spinal stenosis, a multicenter trial demonstrated that incorporating electrical dry needling into spinal manipulation and conventional physical therapy yielded significantly greater improvements in leg pain and Oswestry Disability Index scores than conventional therapy alone, with the difference in disability surpassing the threshold for minimal clinically important difference.¹⁴

The image exhibits less uniformity; however, this perception shifts when the comparison transitions from “EDN-inclusive program versus no EDN” to direct parameter comparisons within EDN itself. In a study involving unilateral mechanical neck pain with active myofascial trigger points in the levator scapulae, percutaneous electrical nerve stimulation demonstrated superior performance compared to non-stimulated dry needling in terms of disability and pressure pain threshold, with mixed outcomes observed for range of motion. This supports the general premise that stimulation confers additional value beyond mere needle insertion^.15

Nevertheless, when Hernandez et al. conducted a direct comparison of dry needling followed by high-frequency versus low-frequency percutaneous electrical nerve stimulation in chronic myofascial neck pain, both groups experienced significant pain reduction, with no statistically significant difference between the groups concerning pain levels or pressure pain threshold. This finding warrants careful consideration: although frequency-specific opioid data from animal models provide mechanistic insights, this short-term human clinical comparison did not demonstrate a clear differentiation in outcomes by frequency selection. This constitutes a notable discrepancy between mechanistic reasoning and clinical application, which honest clinical reporting should acknowledge.¹⁶

Regarding treatment tolerability, Sharma et al. observed that both 2 Hz and 100 Hz intramuscular electrical stimulation significantly alleviated soreness at 24 hours after dry needling, compared with dry needling alone, which showed no significant improvement in the group. This constitutes a valuable, albeit secondary, clinical consideration, particularly for patients who are sensitive to post-treatment discomfort.¹⁷