Myofascial trigger point (MTrP)

A **myofascial trigger point**, often abbreviated MTrP or simply called “trigger point,” is defined as a hyperirritable spot within taut bands of skeletal muscle fibers that produces local tenderness and characteristic referred pain when compressed. These nodules can also cause motor dysfunction—such as restricted movement—and sometimes autonomic changes like skin temperature alteration over the affected area. The pathophysiology remains incompletely understood but may involve abnormal endplate activity leading to sustained sarcomere contraction (“muscle knots”), local hypoxia/metabolic stress with accumulation of sensitizing substances including neuropeptides and cytokines. Trigger points play an important role in myofascial pain syndrome—a common cause of regional musculoskeletal discomfort—and may contribute secondarily to headaches and other chronic soft-tissue pains. They are diagnosed clinically by palpation; there are no definitive laboratory tests or imaging markers for their identification.[1][3][4] Treatment focuses on symptom relief through manual therapies (“trigger point release”), dry needling/acupuncture techniques, physical rehabilitation modalities, topical cooling/stretching methods (“spray-and-stretch”), electrical stimulation therapies—or occasionally via injection with anesthetic agents/corticosteroids/botulinum toxin if conservative measures fail.[6][7]

Other names

Trigger pointMuscle knotMTrPMyofascial pain nodule

The above drugs act by:\n- Local anesthetics block nerve conduction at the site to reduce local and referred pain.\n- Corticosteroids reduce local inflammation.\n- Botulinum toxin inhibits acetylcholine release at neuromuscular junctions to decrease abnormal muscle contraction/tone.[9]\n\nThese mechanisms address symptoms but do not act on any specific molecular entity called \"myofascial trigger point.\"