Wednesday, January 20th 2010
On Wednesday, 20th January, Paul Turner, one of our Branch members, gave a very informative talk on Myofascial Trigger Points and how they could help in podiatry.
A trigger point is a small area of painful or tender tissue within a muscle that can refer pain to distant area, either distally or proximally. An example was given of pain in the jaw resulting from a trigger point in the lower back.
Primary activating factors include
· Persistent muscle contraction, strain, overuse
· Trauma
· Adverse environmental conditions (e.g. sitting in a draught)
· Prolonged immobility, including sitting in the same position for a length of time
· Systemic biochemical imbalance
Secondary factors include compensating synergist and antagonist muscles. Satellite trigger points may also evolve in referral zones.
Clinical features include
· Palpable tight band usually in the muscle belly with tender nodule within the band
· Pain or altered sensation in target zone when nodule is compressed
· Mechanical stimulation of trigger point can cause patient to recognise the current pain complaint (active trigger point) or an unfamiliar pain (latent trigger point)
· Painful limit of stretch ROM
· Local twitch response seen or felt
· Pain on contraction
· Muscle weakness
Also look for
· Increased or decreased local temperature in trigger point or referral zone
· Increased humidity
· Roughened texture
· Local trophic changes e.g goosebumps
· Jump sign
The Integrated Trigger Point Hypothesis (Simons et al 1998) suggests that even though the nerve fibre supplying the muscle is inactive, the chemical messenger ACh is still present to some degree in the synapse, causing release of calcium within the muscle. This results in some of the sarcomeres contracting within the muscle fibres setting up a ‘vicious circle’ of increased energy (ATP) demand, compression of blood vessels, decreased ATP supply leading to failed energy supply and failed reuptake of calcium. Pain, local or referred, occurs as result of this chemical imbalance.
Trigger points can be eliminated by
· Ischaemic pressure
· Spray and stretch
· Ultrasound deep heat therapy
· Thermotherapy
· Needling therapies