Skip to Main Content




Myofascial pain is a common source of pain in the neck, low back, and other areas of the body. The term “myofascial pain” encompasses muscle strain, myofascial trigger points, and specific muscle pain syndromes. These syndromes include piriformis syndrome, iliopsoas related pain, and pain associated with the scalene muscles (trigger points, neurogenic thoracic outlet syndrome).




Skeletal muscle consists of muscle fibers under somatic nervous control. Each nerve root innervates a muscle or group of muscles known as a myotome. The muscle belly of skeletal muscles is connected by tendons to bone. Trigger points occur in the muscle body, most often located in the center of the muscle.




  • Trigger points are hyperirritable localized taut bands of skeletal muscle that produce characteristic referral patterns.

  • A trigger point (TP) may occur in isolation or concomitantly with myofascial pain syndrome or other pain generating syndromes.

  • Trigger points are diagnosed by history and physical examination.

  • A patient will complain of a localized pain or regional pain located in or around any skeletal muscle.

  • The neck, shoulder girdle, and low back are the most common areas involved. Commonly involved muscles are the trapezius, splenii, cervical and lumbar paraspinal muscles, and the quadratus lumborum.

  • On examination, localized taut bands of muscle are noted and palpation produces characteristic nondermatomal referral patterns.1

  • Trigger points may be active or latent. Active trigger points produce spontaneous pain, while latent trigger points produce pain only when palpated.

  • Active trigger points may result from trauma, overload or overuse injury, or due to a muscle being in a prolonged contracted or shortened position.

  • Treatments for active trigger points include physical therapy (stretching and strengthening, conditioning, therapeutic modalities); trigger point injections; acupuncture; biofeedback; transcutaneous nerve stimulation (TENS); and some medications.2, 3, and 4

  • Trigger point injections are intramuscular injections of local anesthetic with or without corticosteroids thought to work by local anesthetic effect, interruption of pain transmission, mechanical effects on the muscle itself, and disruption of ephaptic transmission.


Basic Concerns for Injection


  • Immunocompromised patients, patients at high risk for infection.

  • Patients with metastatic cancer pain may have local masses in the region.

  • Patients may have thrombocytopenia secondary to chemotherapy.

  • Patients with allodynia in the area of injection.




  • Infection, systemic or localized

  • Coagulopathy

  • Distorted or complicated anatomy

  • Patient refusal


Preoperative Considerations


  • Refer to ASRA guidelines, consider the risks and benefits.

  • Anticoagulation—this is less of a concern than for an epidural.

  • Physical examination of the area for infection, skin ulceration or necrosis, and extent of disease.

  • The ability of a patient to tolerate a supine, prone, lateral decubitus, or seated position for the injection.




  • Isopropyl alcohol or chlorhexidine

  • 25-gauge 1.5-in needle

  • 3, 5, ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessAnesthesiology Full Site: One-Year Subscription

Connect to the full suite of AccessAnesthesiology content and resources including procedural videos, interactive self-assessment, real-life cases, 20+ textbooks, and more

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessAnesthesiology

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.