Trigger Point Injections

• Trigger points are discrete, focal, hyperirritable spots located in a taut band of skeletal muscle. They produce pain locally and in a referred pattern and often accompany chronic musculoskeletal disorders.
• The spots are painful on compression and can produce referred pain, referred tenderness, motor dysfunction, and autonomic phenomena. Physician’s sense of feel and patient expressions of pain upon palpation are the most commonly used method to localize a trigger point. The most common physical finding is palpation of a hypersensitive bundle or nodule of muscle fibre of harder than normal consistency. The palpation will elicit pain over the palpated muscle and/or cause radiation of pain towards the zone of reference in addition to a twitch response

When areas of muscle that have become tight and inflamed, often a tender knot or tight band forms at the spot.

Trigger points can be caused by a variety of conditions, including the following:

• • Back pain, which typically occurs after a fall, injury or heavy lifting, and is chronic, persisting for three months or longer
  • Neck pain
  • Chronic tension from stress
  • Fibromyalgia
  • Myofascial pain syndrome, (also called chronic myofascial pain) is a condition in which connective tissue called fascia tightens and contracts; this is usually from an injury or overuse (repetitive motion)
  • Poor posture
  • Migraine or tension headaches
  • Traumatic or overuse (repetitive motion) sports or other injury

• Trigger points are classified as being active or latent, depending on their clinical characteristics. An active trigger point causes pain at rest. It is tender to palpation with a referred pain pattern that is similar to the patient’s pain complaint. This referred pain is felt not at the site of the trigger-point origin, but remote from it. The pain is often described as spreading or radiating. Referred pain is an important characteristic of a trigger point. It differentiates a trigger point from a tender point, which is associated with pain at the site of palpation only.
• A latent trigger point does not cause spontaneous pain, but may restrict movement or cause muscle weakness. The patient presenting with muscle restrictions or weakness may become aware of pain originating from a latent trigger point only when pressure is applied directly over the point
• Patients who have trigger points often report regional, persistent pain that usually results in a decreased range of motion of the muscle in question. Often, the muscles used to maintain body posture are affected, namely the muscles in the neck, shoulders, and pelvic girdle, including the upper trapezius, scalene, sternocleidomastoid, levator scapulae, and quadratus lumborum.

• When left untreated, trigger point disfunction can induce a chronic pain state. This often manifests in headaches, muscle aches, morning stiffness, TMJ syndrome, tinnitus, or other painful syndromes, sometimes located away from the active trigger point site.
• Over time, patients may also experience increased muscle weakness or imbalance, altered motor recruitment, in either the affected muscle or in functionally related muscles, Changes in Range of Motion (ROM), or Postural abnormalities.