What is a Trigger Point?
Dr’s Travell and Simons defined a myofascial trigger point as a “hyperirritable spot in a skeletal muscle”. The spot is painful on compression and can give rise to characteristic referred pain, referred tenderness, motor dysfunction and autonomic phenomena.
Myofascial trigger points are commonly seen in both acute and chronic pain conditions. Hendler and Kozikowski suggest that myofascial trigger points as the most commonly missed diagnosis in chronic pain patients.
Why Do Trigger Points Cause Pain?
According to Dr. Gunn, ‘Shortening in muscles acting across a joint increases joint pressure, upsets alignment, and can precipitate pain in the joint, i.e. arthralgia.’ Muscle release, massage or dry needling of the ‘shortened’ muscle band can cause an immediate palpable relaxation. A sense of release and increased range of motion is often experienced by the patient.
When used in conjunction with motor control retraining and postural and movement retraining, the release obtained from treatment can be long lasting.
How Are Trigger Points Treated with Dry Needling?
Over the years it has been shown that it is possible to deactivate triggers points by injecting them with a large number of varying substances, including saline (salt water) placebo. It has been subsequently suggested then, that only consistent factor is that the pain relief is obtained from the stimulation of the needle used for the injection itself, rather than the drug or saline solution used. This mechanical needle stimulation of the trigger point without the use of a drug is known as Dry Needling!
The needle sites can be at the epicentre of taut, tender muscle bands, or they can be near the spine where the nerve root may have become irritated and supersensitive. Penetration of a normal muscle is painless; however, a shortened, supersensitive muscle will ‘grasp’ the needle in what can be described as a cramping sensation. The result is a stimulation of the stretch receptor in the muscle (muscle spindle), producing a reflex relaxation or lengthening response.