Myofascial pain is a major cause of musculoskeletal pain
- described as a pain that arises from trigger points which are focal, tender areas within a taut band of skeletal muscle that may produce pain, vasoconstriction or vasodilation in a distant region either by local pressure or spontaneously
- known as the trigger point phenomena
- multiple precipitating factors have been suggested which include
- trauma,
- poor posture,
- degeneration,
- nerve root compression,
- endocrine, metabolic and nutritional deficiencies,
- chronic infection,
- emotional and psychological stress,
- and sleep disturbance
Myofascial pain is a great mimicker and in the lower limb can present as pain in the hip or knee
- other pathologies such as infection, fractures, malignancy and neurological injuries need to be excluded.
Myofascial pain from the iliopsoas, piriformis, tensor fascia lata, pectineus, quadriceps and sartorius can be referred to the groin or thigh
- patients who have myofascial pain may have asymmetry of their posture and gait due to muscular pain and tightness
- main finding on examination is tenderness on palpation of the specific muscle
- a local twitch response can be elicited by snapping palpation or needling of the trigger point (1)
Radiological investigations are useful only to exclude other causes of pain
- myofascial pain itself will not show up on any investigation
- ultrasound guided specific muscle injections of small amounts of local anaesthetic are helpful in diagnosis
Treatment
- mainly simple analgesia such as paracetamol, NSAIDs or opioid analgesia, depending on the severity of pain
- physiotherapy modalities include massage, ultrasonography, acupuncture, transcutaneous electric nerve stimulation and application of ice and or heat
- injection therapy into trigger points may be required if non-invasive treatment fails
- options include use of local anaesthetics, corticosteroid, dry needling or botulinum toxin
Reference:
- 1) Yap EC. Myofascial pain e an overview. Ann Acad Med Singapore 2007; 36: 43-8.