Letter to the Editor: Trigger Points in Shoulder Pain: The Importance of Myofascial Pain Syndrome Perception and Dry Needling Treatment Protocols

Dear Editor:

With a lifetime prevalence of ∼67% and a point prevalence, ranging from 7% to 26%, shoulder pain is a significant health issue.¹ Myofascial pain syndrome (MPS) is one of the most-frequent and overlooked causes of musculoskeletal pain due to the myofascial trigger points (MTrPs) located in muscle tissue.² Dry needling—which is an essential component of acupuncture in general as well as being a subtype of Western medical acupuncture—is a treatment that is increasingly gaining popularity. It is also a microinvasive and cost-effective approach with a low risk of side-effects when used to treat MTrP-related pain.^3,4 Given that there is no specific law on dry needling in Turkey, use of this modality is based on Turkey's general law on medical practice, which only authorizes medical doctors to practice dry needling.⁵ Currently, there is no specific certification program for dry needling practice in Turkey. This letter addresses the importance of MTrPs in causing shoulder pain and treatment of these MTrPs with dry needling (Fig. 1).⁶

FIG. 1.

Pain referral pattern and dry needling procedure in the muscles that can cause shoulder pain. (A) Trigger point locations and pain referral pattern of the anterior part of the deltoid muscle. (B) Application of dry needling to the anterior part of the deltoid muscle with the pincer palpation technique. (C) Trigger point locations and pain referral pattern of the lateral part of the deltoid muscle. (D) Application of dry needling to the lateral part of the deltoid muscle with the pincer palpation technique. (E) Trigger point locations and pain referral pattern of the posterior part of the deltoid muscle. (F) Application of dry needling to the posterior part of the deltoid muscle with the pincer palpation technique. (G) Trigger point locations and pain referral pattern of the supraspinatus muscle. (H) Application of dry needling to the supraspinatus muscle with the flat palpation technique. (I) Trigger point locations and pain referral pattern of the infraspinatus muscle. (J) Application of dry needling to the infraspinatus muscle with the flat palpation technique. (K) Trigger point locations and pain referral pattern of the teres major muscle. (L) Application of dry needling to the teres major muscle with the pincer palpation technique. (M) Trigger point locations and pain referral pattern of the teres minor muscle. (N) application of dry needling to the teres minor muscle with the flat palpation technique. (O) Trigger point locations and pain referral pattern of the subscapularis muscle. (P) Application of dry needling to the subscapularis muscle with the pincer palpation technique.

The MTrPs of the anterior and lateral parts of the deltoid muscle cause local pain in the area where the myofascial trigger point is localized. Intervention is performed when the patient is in a side-lying position. Needling is performed with the pincer palpation technique, for which 0.30 × 30–mm needles are sufficient.⁷

MTrPs of the posterior part of the deltoid causes local pain in the area where it is localized. Needling is performed with the pincer palpation technique, for which 0.30 × 30–mm needles are sufficient. Care should be taken not to penetrate the needle into the glenohumeral joint.⁷

The supraspinatus muscle's MTrPs may cause radiating pain in the middle deltoid region, the arm and forearm's lateral side, and the elbow's lateral epicondyle region.⁸ Needling is performed with the flat palpation technique. The needle should penetrate the skin perpendicularly from the cranial to the caudal direction, and 0.30 × 50–mm needles should be used.⁷

MTrPs of the infraspinatus muscle may cause pain radiating to the anterior part of the shoulder region, mid-deltoid area, ventrolaterally along the arm to the forearm, and radial region of the hand.⁸ Needling is performed with the flat palpation technique. It is essential to detect the scapula anatomically, and a 0.30 × 30–mm needle is used.⁷

The teres major muscle's MTrPs can result in reflected pain in the dorsal forearm, posterior deltoid, around the long head of the triceps muscle, and in the glenohumeral joint. Needling is performed with the pincer palpation technique, for which 0.30 × 30–40–mm needles should be used. Care should be taken to avoid pneumothorax.⁷

Trigger points of the teres minor muscle may cause reflected pain in the posterior shoulder. Needling is performed with the patient in the prone position. The flat palpation technique is used. The needle should penetrate the skin perpendicularly from the posterior to the anterior area. A 0.30 × 30–mm needle should be used. Care should be taken to avoid pneumothorax.⁷

Pain caused by MTrPs of the subscapularis muscle concentrates in the posterior shoulder region. Needling is performed with the pincer palpation technique. The needle should penetrate the skin perpendicularly in a medial-to-lateral direction. Care should be taken to avoid pneumothorax, as there is a needle passage between the medial scapula and the costa. A 0.30 × 50–mm needle should be used.⁷

Dr. Temel was responsible for the conceptualization, methodology, and data curation needed to prepare this letter. He also wrote its original draft. Dr. Bağcıer was involved with visualizing, supervising, investigating, and validating the data supporting the information in this letter, as well as reviewing, and editing the content. Both authors chose the software used and wrote the final version of the letter.

The data that supported the findings discussed in this letter are available from the corresponding author, Dr. Temel, upon reasonable request.