The effects of dry needling on muscle blood flow of the infraspinatus muscle in individuals with shoulder pain - a randomized clinical trial
Brown et al. · Journal of Manual & Manipulative Therapy · 2025
Evidence Level
STRONGOBJECTIVE
To examine the effects of dry needling on blood flow of the infraspinatus muscle in people with shoulder pain using color Doppler ultrasound
WHO
40 people aged 18-65 years with non-traumatic shoulder pain and myofascial trigger points in the infraspinatus
DURATION
Single session with assessment immediately before and after treatment
POINTS
Myofascial trigger points in the infraspinatus muscle, 2-4 points per participant
🔬 Study Design
Real Dry Needling
n=20
Real needling at infraspinatus trigger points for 10 seconds
Sham Dry Needling
n=20
Streitberger placebo needle without skin penetration
📊 Results in numbers
Reduction in peak systolic velocity
Improvement in shoulder internal rotation
Improvement in shoulder external rotation
Change in pressure pain threshold
📊 Outcome Comparison
Peak Systolic Velocity (cm/s)
This study showed that real dry needling improves blood flow in the shoulder muscle and increases range of motion. This means the treatment can help relax the muscle and reduce tension, offering relief for people with shoulder pain.
Article summary
Plain-language narrative summary
This randomized controlled trial investigated the effects of dry needling on blood flow of the infraspinatus muscle in people with shoulder pain. The research is important because myofascial trigger points are common in the shoulder region and can contribute to chronic symptoms, with blood flow problems proposed as an underlying mechanism of these painful points. The study involved 40 participants aged 18 to 65 years who had non-traumatic shoulder pain and at least one trigger point in the infraspinatus muscle. Participants were randomly divided into two groups: one received real dry needling and the other received sham treatment with a fake needle.
The methodology was rigorous, using color Doppler ultrasound to measure blood flow parameters, a goniometer for range of motion, and a computerized algometer for pressure pain threshold. Measurements were performed immediately before and after a single treatment session. The main results showed that real dry needling significantly reduced peak systolic blood flow velocity, indicating less resistance to flow and better muscle perfusion. This suggests that the treatment promotes muscle relaxation and vasodilation.
In addition, participants who received real needling showed significant improvements in shoulder range of motion, with an increase of 6.8° in internal rotation and 4.5° in external rotation, values that exceed the minimal detectable change. Contrary to expectations, there were no significant differences in pressure pain threshold between the groups. This may be explained by the fact that participants had low initial pain levels and mild disability, in addition to the possible influence of post-needling soreness that may mask immediate changes in sensitivity. The proposed mechanism for the observed benefits includes reduced capillary compression through disruption of the muscle contracture associated with trigger points, as well as biochemical changes that lead to vasodilation.
Needling may reduce abnormal electrical activity at trigger points, promoting muscle relaxation and improving the local vascular environment. The clinical implications are promising, providing additional evidence for the use of dry needling in the management of shoulder pain. Immediate improvements in blood flow and range of motion suggest that the treatment can be effective in relaxing tight muscles and improving shoulder function. However, the study had important limitations, including the lack of differentiation between active and latent trigger points, which may explain some non-significant results.
In addition, only immediate effects were assessed, and future studies are needed to investigate medium- and long-term effects.
Strengths
- 1Randomized placebo-controlled design using a validated Streitberger needle
- 2Use of color Doppler ultrasound for objective measurement of blood flow
- 3Rigorous methodology with assessors blinded to interventions
- 4Well-defined inclusion criteria and a homogeneous population
- 5Standardized measurements with good test-retest reliability
Limitations
- 1Lack of differentiation between active and latent trigger points
- 2Assessment of immediate effects only, without follow-up
- 3Relatively small sample size (n=40)
- 4Possible influence of post-needling soreness on pain threshold measurements
- 5Lack of control over medication use and time of data collection
Expert Commentary
Dr. Marcus Yu Bin Pai
MD, PhD · Pain Medicine · Physical Medicine and Rehabilitation · Medical Acupuncture
▸ Clinical Relevance
Infraspinatus dysfunction from myofascial trigger points is a routine finding in patients with impingement syndrome, resolving adhesive capsulitis, and functional glenohumeral instability. What this trial adds to clinical reasoning is objective hemodynamic evidence — measured by color Doppler — that a single dry needling session produces a significant reduction in peak systolic velocity, indicating lower intramuscular vascular resistance and improved tissue perfusion. From a physiatric standpoint, this translates the energy crisis model of trigger points into measurable physiological data, not just subjective reports. Immediate gains of 6.8° in internal rotation and 4.5° in external rotation surpass the minimal detectable change and have direct relevance for decisions about progression of the rehabilitation protocol. Populations such as athletes with overuse shoulder pain and workers with chronic postural overload are natural candidates to benefit from this approach.
▸ Notable Findings
The most intriguing finding is the dissociation between outcomes: real needling objectively modified muscle hemodynamics and joint mobility but did not significantly alter the pressure pain threshold. This challenges the premise that immediate mechanical analgesia is the main effect of a single session, suggesting that the vascular-metabolic pathway — and not sensory neuromodulation — predominates in the acute effect. The reduction in peak systolic velocity is interpreted as relative vasodilation secondary to the disruption of the myofibrillar contracture, consistent with the Simons model of motor endplate dysfunction. That these vascular effects precede the analgesic change has implications for therapeutic sequencing: needling may prepare the tissue for subsequent interventions — mobilization, eccentric strengthening — more efficiently than directly modifying central sensitivity at this stage.
▸ From My Experience
In my practice at the Pain and Rehabilitation Center, the infraspinatus is, along with the descending trapezius, the muscle I needle most frequently in patients with chronic painful shoulder. I typically observe a functional response within the first two to three sessions — the patient reports being able to reach the seatbelt or comb their hair with less difficulty, even before reporting significant pain relief. This pattern corresponds exactly to the dissociation described in the study. I habitually work with cycles of six to eight sessions for stabilization, combining needling with strengthening exercises for the external rotators in the same week — the mobility recovered immediately after the session creates a therapeutic window that physical therapy must take advantage of immediately. I avoid prescribing the procedure in isolation in patients with marked central hypersensitization, since post-needling soreness can worsen the experience without proportional gain. The profile that responds best, in my experience, is exactly the one described in the study: moderate pain, mild to moderate functional disability, and a well-defined latent or active trigger point.
Full original article
Read the full scientific study
Journal of Manual & Manipulative Therapy · 2025
DOI: 10.1080/10669817.2025.2464542
Access original articleScientific Review
Marcus Yu Bin Pai, MD, PhD
CRM-SP: 158074 | RQE: 65523 · 65524 · 655241
PhD in Health Sciences, University of São Paulo. Board-certified in Pain Medicine, Physical Medicine and Rehabilitation, and Medical Acupuncture. Scientific review and curation of every entry in this library.
Learn more about the author →Medical disclaimer: This content is for educational purposes only and does not replace consultation, diagnosis, or treatment by a qualified professional. Some information may be assisted by artificial intelligence and is subject to inaccuracies. Always consult a physician.
Content reviewed by the medical team at CEIMEC — Integrated Centre for Chinese Medicine Studies, a reference in Medical Acupuncture for over 30 years.
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