What is Myofascial pain..?

The myofascial pain syndrome relates to pain muscles and connective tissue. It  is a common clinical complaint caused by myofascial trigger points.

A myofascial trigger point is defined as a hyperirritable spot or knot, usually within a taut band of skeletal muscle which is painful on compression and can cause referred pain (pain in a different body area in relation to the actual cause), motor (muscle movement) dysfunction and autonomic symptoms (such as organ function).

Pathophysiology
The initial change in muscle that is associated with myofascial pain seems to be the development of the taut band, which is in term a motor abnormality. Several mechanisms have been hypothesied to explain this motor abnormality. One theory is that sympathetic nervous system activity increases acetylcholine release and that local hypoperfusion caused by the muscle contraction (taut band) resulted in muscle ischemia or hypoxia leading to an acidification of the pH.
The prolonged ischemia also leads to muscle injury resulting in the release of potassium, bradykinins, cytokines, ATP, and substance P which might stimulate nociceptors (pain sensory neurons) in the muscle. The end result is the tenderness and pain observed in myofascial trigger points.
Depolarization of nociceptive neurons causes the release of calcitonin gene-related peptide (CGRP).

Despite the common presentation of myofascial trigger points, there are very few studies found in the scientific literature that investigate their cause and course.

Classification and Clinical Presentation
Myofascial trigger points are classified into active and latent trigger points. An active trigger point is one with spontaneous pain or pain in response to movement that can trigger local or referred pain. A latent trigger point is a sensitive spot with pain or discomfort only elicited in response to compression.

The myofascial trigger points (active or latent) have common clinical characteristics such as:

Pain on compression that can be local pain and/or referred pain that is similar to a patient’s main clinical complaint or may aggravate the existing pain.
Local twitch response:  which is a quick contraction of the muscle fibers in or around the taut band of muscle .
Muscle tightness. Restricted range of motion, and sensitivity during stretching.

Local myasthenia: The muscle with a trigger point may be weak, but usually no atrophy can be noticed.
Patients with trigger points may have associated localized autonomic/symptoms, including vasoconstriction, pilomotor response and hypersecretion (eg increased sweating).

 

When the pain resulting from an active trigger point becomes persistent the patient may develop satellite trigger points. A satellite trigger point is localised in the referral zone of the primary trigger point (i.e. the active trigger point that was originally activated), usually in an overloaded synergist muscle. This referral zone corresponds to the pain pattern described by the patient, it is often described as a diffuse pain, usually distant to the active trigger point location.
Etiology
Several possible mechanisms can lead to the development of myofascial trigger points, including:Low-level muscle contractions

  • Muscle contractures due to biomechanical stress or neurological dysfunction
  • Direct tramua
  • Muscle overload
  • postural stress
  • Unaccustomed muscle contractions.
  • unaccustomed muscle contractionsmaximal or submaximal muscle contractions:  high amounts of energy (ATP) are required. When the demands of exercise begin to exceed the ability of the muscle cells to produce ATP, anaerobic glycolysis will begin consuming more and more of the available intracellular ATP. The muscle will eventually run out of ATP and sustained muscle contractions may occur, starting the development of trigger points.

    Perpetuating Factors
    In some cases perpetuating factors may be active such as:
  • Scoliosis
  • Leg length discrepancies
  • Joint hypermobility
  • Muscle overuse

There are systemic or metabolic perpetuating factors such as:

  • Hypothyroidism
  • Iron insufficiency
  • Vitamin D insufficiency
  • Vitamin C insufficiency
  • Vitamin B12 insufficiency

Psychosocial per perpetuating factors:

  • Stress
  • Anxiety

And other possible perpetuating factors:

  • Infectious disease
  • Parasitic diseases (eg lyme disease)
  • Polymyalgia rheumatica
  • Use of statin-class drugs

Diagnosis
Palpation (feeling with the hands during physical examination)is the gold standard in identifying the presence of taut bands in muscle. This involves the accurate skills of physiotherapists to identify these taut bands. This requires precise knowledge of muscle anatomy, direction of specific muscle fibres and muscle function.

 

Recent research has shown interesting results using magnetic resonance elastography and sonoelastography combined with Doppler imaging. Ballyns et al. showed in their study that sonoelastography can be a useful tool to classify myofascial trigger points by area. Larger areas correspond to active trigger points and smaller ones to latent trigger points.


Management
There are two different approaches in the treatment of myofascial trigger points. There are non-invasive techniques such as Ultrasound therapy, Low-level laser therapy, Transcutaneous Electrical Nerve Stimulation (TENS), drug therapy and several physical and manual therapy techniques such as:

Stretching techniques (e.g. spray and stretch)
Post-isometric relaxation
Active Release Techniques
Trigger point pressure release
Muscle energy techniques
Massage
Dry needling

At PhysioCare we can help by determining the problem and an appropriate course of treatment for your specific problem and get you back on track, living life to the fullest.

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