Multi-Acupuncture Point Injections and Their Anatomical Study in Relation to Neck and Shoulder Pain Syndrome (So-Called Katakori) in Japan
Terayama et al. · PLoS ONE · 2015
Evidence Level
MODERATEOBJECTIVE
Investigate the clinical efficacy of multi-acupuncture point injections (MAPI) for katakori (Japanese neck and shoulder pain syndrome) and anatomically study the sites reached by the medication
WHO
9 Japanese patients with idiopathic katakori without underlying disease, 6 men and 3 women, mean age 57.1 years
DURATION
Immediate post-injection assessment and follow-up of the therapeutic effect period
POINTS
BL-10, GB-21, LI-16, SI-14, and BL-38 with 1 mL of mepivacaine 1% at each point simultaneously
🔬 Study Design
Patients with katakori
n=9
Simultaneous injections at 5 acupuncture points
Anatomical study
n=3
Cadavers with India ink injection at the same points
📊 Results in numbers
Reduction on the Pain Relief Scale (PRS)
Statistical significance of improvement
Duration of therapeutic effect
Presence of trigger points
Presence of tender points
Percentage highlights
📊 Outcome Comparison
Pain Relief Scale (PRS — where 10 = maximum pain)
This Japanese study investigated a technique of simultaneous injections at 5 specific acupuncture points to treat neck and shoulder pain (called 'katakori' in Japan). The results showed significant pain reduction even in patients without classic trigger points, suggesting a promising approach for this type of muscular pain.
Article summary
Plain-language narrative summary
This pioneering study investigated the clinical efficacy and anatomical mechanisms of multi-acupuncture point injections (MAPI) for the treatment of katakori, a myofascial pain syndrome of the neck and shoulders unique to Japanese culture. Katakori represents a significant public health problem in Japan, being the second most common symptom in men and the most common in women, particularly affecting middle-aged and older populations. The condition is characterized by subjective discomfort, spontaneous pain, and abnormal muscle tension in the cervical, scapular, and interscapular regions, with similarities to myofascial pain syndrome but distinct features. The retrospective study included 9 Japanese patients with idiopathic katakori (6 men, 3 women, mean age 57.1 years) treated between January and December 2013.
Concurrently, an anatomical study was conducted on 3 female cadavers to investigate the anatomical distribution of the injections. The MAPI technique consisted of simultaneous injections of 1 mL of mepivacaine 1% at five specific acupuncture points: BL-10 (lateral border of the suboccipital trapezius muscle), GB-21 (midpoint between C7 and the acromion), LI-16 (lateral border of the supraspinous fossa), SI-14 (medial side of the superior angle of the scapula), and BL-38 (midpoint of the medial border of the scapula). The selection of these points was based on the authors' clinical experience, regardless of the presence of tender points or trigger points at the specific sites. Clinical results demonstrated significant treatment efficacy.
The Pain Relief Scale (PRS) decreased significantly from 10 (maximum pre-treatment pain) to 2.23 ± 2.0 (p < 0.00001) in all patients. Even in the three cases with trigger points present, a significant reduction to 2.0 ± 2.7 (p < 0.05) was observed. The therapeutic effect period was 6.33 ± 4.2 days. Notably, pain relief was obtained regardless of the presence or absence of trigger points, suggesting that the mechanism of action may differ from traditional trigger point injections.
The anatomical study revealed valuable information about the distribution of the injected medication. Using India ink as a marker, it was possible to map precisely where the solution distributed at each point: BL-10 affected the fascia of the rectus capitis posterior major and minor muscles; GB-21 and LI-16 reached the fascia of the supraspinatus muscle; SI-14 and BL-38 reached the fascia of the rhomboid muscle. All points demonstrated distribution in the space between muscles and muscular fasciae, regions rich in free nerve endings and nociceptors. Neurological analysis revealed that the affected muscles are innervated by the anterior and posterior branches of the C1-C6 cervical nerves, suggesting that the effect of MAPI may involve coordinated suppression of pain sensitivity through the central nervous system.
The proposed mechanism includes reversible blockade of action potential conduction in somatic and autonomic nerves by mepivacaine, in addition to a 'vicious pain cycle interruption effect' through relaxation of muscle tension. This is the first study to demonstrate both the clinical efficacy and the anatomical foundations of MAPI for katakori. The technique proved more standardized and potentially more accessible than searching for specific trigger points, not requiring the same level of technical experience. The study also identified an important safety consideration, as the dissection revealed the proximity of the suprascapular arteries and nerves and the vertebral arteries in the suboccipital triangle region, requiring special care during implementation to avoid acute anesthetic intoxication and hematoma formation.
Strengths
- 1First study combining detailed clinical and anatomical analysis for katakori
- 2Innovative methodology using India ink to map anatomical distribution
- 3Standardized technique independent of specific trigger point localization
- 4Statistically significant results despite the small sample
Limitations
- 1Very small sample (n = 9), limiting generalization of results
- 2Retrospective study without a control group
- 3Lack of long-term follow-up of patients
- 4Limited to Japanese population with a culturally specific condition
Expert Commentary
Prof. Dr. Hong Jin Pai
PhD in Sciences, University of São Paulo
▸ Clinical Relevance
Katakori, although a diagnosis culturally rooted in Japanese medicine, represents a clinical phenotype that any physician treating cervical and myofascial pain immediately recognizes in practice: diffuse muscle tension, spontaneous pain, and subjective discomfort in the cervical, scapular, and interscapular regions, frequently without identifiable classic trigger points. The relevance of this work lies precisely there—demonstrating that injections at anatomically grounded acupuncture points (BL-10, GB-21, LI-16, SI-14, and BL-38) produce significant relief regardless of the presence of trigger points. For the physician working with cervical myofascial pain, this expands the therapeutic armamentarium for cases—numerous in practice—in which the physical exam does not delineate a discrete trigger point, but the patient presents with a disabling pain syndrome. Standardization of the technique, without depending on locating individual trigger points, makes the approach more replicable and trainable in institutional settings.
▸ Notable Findings
The anatomical correlation obtained with India ink injections in cadavers is the most singular finding of this article. By precisely mapping where mepivacaine distributes at each of the five points, the authors demonstrate that the fascial planes between muscles—rectus capitis posterior, trapezius, supraspinatus, and rhomboid—are the real targets of the injection, and that these planes are densely innervated by the anterior and posterior branches of the C1-C6 cervical nerves. This provides a concrete neuroanatomical substrate for the proposed mechanism of action: coordinated suppression of somatic and autonomic nociception via reversible blockade of axonal conduction, with interruption of the pain-spasm-pain cycle. The reduction of the PRS from 10 to 2.23 with p < 0.00001—even in a small sample—and the duration of effect of approximately 6 days per session are data that guide therapeutic planning. The fact that 33.3% of patients had trigger points and all obtained equivalent relief reinforces that the mechanism extends beyond the lysis of localized contractures.
▸ From My Experience
In my practice at the Pain Center, cervical myofascial pain without well-defined trigger points represents perhaps a third of referrals—patients with diffuse tension, without the classic palpable nodule, for whom trigger-point-guided injection does not directly apply. I have observed that, in these cases, injections or dry needling at anatomically selected points along the cervical and scapular fascial planes produce a clinical response comparable to conventional trigger point treatment, generally perceptible after two to three sessions. The five-point protocol described by the authors is elegant for its anatomical symmetry and its segmental coverage of C1-C6; we typically use similar configurations, sometimes adding electroacupuncture to enhance regional muscle relaxation. The safety attention raised by the authors is absolutely pertinent: the proximity of the vertebral and suprascapular arteries at BL-10 and GB-21 demands precise technique, careful angulation, and prior aspiration—points I systematically reinforce in resident training. For maintenance, biweekly sessions over two to three months, combined with postural physical therapy, have produced the most durable results we observe in these patient profiles.
Full original article
Read the full scientific study
PLoS ONE · 2015
DOI: 10.1371/journal.pone.0129006
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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