Theeffectofdryneedlinginthetreatmentofmyofascialpainsyndrome:arandomizeddouble-blindedplacebo-controlledtrial

Myofascial pain syndrome (MPS) is a common and often debilitating condition characterized by highly localized, hyperirritable spots in skeletal muscle known as myofascial trigger points. These trigger points can cause spontaneous pain, referred pain patterns, reduced range of motion, and significant impairment in daily functioning. The prevalence of MPS among individuals with regional pain complaints ranges widely from 21% to 85%, making it one of the most frequent sources of musculoskeletal pain in clinical practice. While numerous treatments exist—including physical therapy, exercise, ischemic compression, heat, stretch and spray techniques, acupuncture, local injections, and pharmacological approaches—the optimal management strategy remains debated.

Trigger point injection has traditionally been considered one of the most effective methods, but since Lewit's seminal observation that the mechanical effect of needling itself may be distinct from any injected substance, dry needling has gained increasing attention. However, previous randomized clinical trials and systematic reviews have yielded contradictory results regarding dry needling's superiority over sham interventions, with some studies finding no difference between penetrating and non-penetrating needle approaches. This controversy, combined with the technical challenges of performing and controlling for needling interventions, created a pressing need for well-designed studies using precise methodology.

The researchers conducted a prospective, double-blinded, randomized placebo-controlled trial in an outpatient physical medicine and rehabilitation clinic. They recruited 39 patients with established myofascial pain syndrome over a 6-month period, applying strict diagnostic criteria based on Travell and Simons' established standards—requiring five major criteria plus at least one minor criterion for inclusion. Major criteria included localized spontaneous pain, spontaneous pain or altered sensations in expected referred pain areas, a palpable taut band, exquisite localized tenderness at a precise point along that band, and measurable reduced range of movement. Minor criteria included reproduction of pain by pressure on the trigger point, elicitation of a local twitch response, or pain relief from muscle stretching or injection.

Patients were randomized into two groups using computer-generated randomization: 22 received active dry needling and 17 received sham dry needling. The active treatment involved inserting standard single-use sterile acupuncture needles (0.25 mm × 25 mm) perpendicularly through the skin directly into the trigger point, with immediate withdrawal after pricking. The sham intervention used a blunted needle that created a pricking sensation but did not penetrate the skin, with pressure applied through an insertion tube to enhance blinding and avoid two-point discrimination. Both groups received identical treatment schedules: six sessions over 4 weeks, with twice-weekly sessions for the first 2 weeks and once-weekly sessions for the final 2 weeks.

Importantly, no exercise programs or physical therapy modalities were provided during the treatment period, and patients were restricted to paracetamol only for analgesia.

Outcome assessments were performed by a physician blinded to group allocation at three time points: before treatment (baseline), after the first session (pain only), and after the sixth session (pain and quality of life). Pain was measured using a 10-cm visual analog scale, and quality of life was assessed with the validated Turkish version of the Short Form-36. The presence of local twitch response was also documented in the active treatment group.

The study demonstrated clear superiority of dry needling over sham intervention for pain reduction. In the dry needling group, visual analog scale scores showed progressive and significant decreases between all assessment points: from 6.6 ± 1.3 at baseline to 4.0 ± 1.6 after the first session, and further to 2.2 ± 2.0 after the sixth session (p = 0.000 for first vs. second assessment; p = 0.000 for second vs. third assessment; p = 0.000 for first vs. third assessment). By contrast, the sham group showed only modest initial improvement—from 6.4 ± 1.6 to 5.4 ± 1.6 after the first session—with no further significant change at the final assessment (5.3 ± 1.8). The between-group comparisons revealed similar baseline scores but significantly lower pain scores in the dry needling group at both the second assessment (p = 0.034) and third assessment (p < 0.001).

General linear model analysis confirmed that treatment type significantly predicted final VAS scores even after adjusting for baseline values (F = 36.200; p < 0.001).

Quality of life improvements followed a similar pattern. All SF-36 subscale scores—physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health—significantly increased in the dry needling group (all p < 0.05). In the sham group, only the vitality subscale showed significant improvement. Medication use also differentiated the groups: paracetamol consumption significantly decreased in the dry needling group (p < 0.001) but not in the sham group (p = 0.157), with between-group differences significant after treatment (p < 0.01).

Exploratory analysis of the local twitch response suggested additional clinical relevance. Among patients receiving active dry needling, those with a positive twitch response showed pain score reductions between first and third assessments, while SF-36 subscales did not significantly change in this subgroup analysis. No treatment-related complications were observed in either group.

This study provides meaningful evidence that genuine dry needling—specifically penetrating needling directly into myofascial trigger points—offers clinically significant advantages over non-penetrating sham needling for patients with myofascial pain syndrome. The findings suggest that the therapeutic effect depends on more than skin stimulation or placebo mechanisms, pointing toward deeper tissue mechanisms involving muscle afferents and possibly polymodal receptors near trigger points.

For clinicians, several practical implications emerge. First, technique matters: the precise localization of trigger points, perpendicular needle insertion to adequate depth, and elicitation of local twitch responses appear important for optimal outcomes. Second, the treatment schedule used here—intensive initial twice-weekly sessions transitioning to weekly maintenance—produced measurable benefits within 4 weeks. Third, the combination of pain reduction, quality of life improvement, and reduced analgesic consumption supports dry needling as a potentially cost-effective intervention that may decrease reliance on medications.

For patients, these results suggest that dry needling performed by experienced practitioners can provide genuine relief beyond placebo effects, though expectations should remain realistic—the average pain reduction was substantial but not complete, and individual responses varied. The safety profile appears favorable with no complications observed, though the small sample size limits definitive conclusions about rare adverse events.

The study also highlights ongoing uncertainties. The lack of long-term follow-up means durability of benefits remains unknown. The relatively small sample, single-center design, and specific population (military hospital outpatients) may limit generalizability. Additionally, whether the local twitch response truly predicts better outcomes requires further investigation, as does the optimal needle type for different body regions and muscle depths.

Nevertheless, this carefully designed trial contributes meaningfully to resolving prior controversies by demonstrating that when performed with technical precision, dry needling exceeds sham intervention effects for myofascial pain syndrome.