What are myofascial trigger points?
They are defined as a ‘hyperirritable locus within a taut band of skeletal muscle, located in the muscle tissue or its associated fascia’ (Travell and Simons 1983). Essentially it is a tight area (knot) within a muscle that can cause spontaneous pain referral into a completely different area to where the muscle is. The pain patterns for most muscles have been well established by Travell and Simons, a common example is the anterior fibres of the upper Trapezius muscles causes neck pain and temporal headaches. Trigger points can develop after an acute (lifting/carrying something heavy) or chronic (poor posture overload) muscle strain. Both of these result in a small area of damage which is slow to heal and in turn causes persistent pain generation due to the formation of a trigger point. Pain is often dull in nature but it can cause other common symptoms such as tingling and numbness in its referral zone. Symptoms are usually referred away from the trigger point and the painful area may not even include the trigger point itself. The severity of the symptoms can vary dramatically both between different patients and overtime in the same patient. Trigger points are very common and most people develop at least one during their lifetime and certain factors can precipitate and perpetuate there development such as emotional stress, exhaustion and metabolic conditions including hypothyroidism.
Trigger points can be classified as either active or latent. Active trigger points cause spontaneous pain at rest and palpation of these points causes localised pain and a pain referral pattern similar to the patients’ complaint. Often the pain is described as a poorly localised deep radiating ache and movement may sometimes exacerbate symptoms. Latent trigger points on the other hand do not cause spontaneous pain but referred pain is elicited on palpation. Muscles with latent trigger points are often tight and weak and a latent trigger point can develop into an active one. Furthermore trigger points are divided into primary secondary or satellite points. Primary ones are trigger points that have been activated directly by acute or chronic muscle overload whereas secondary trigger points develop due to the dysfunction caused by a primary trigger point or other somatic or visceral pathology. Satellite trigger points are secondary trigger points that develop within the referral zone of an active trigger point. Identifying primary trigger points is the key to treatment success as often satellite trigger points will remain active until the primary trigger point has been deactivated.
What makes a trigger point a trigger point?
- A hyperirritable locus within a taut band of skeletal muscle. Therefore a trigger point is a small specific tight area sometimes referred to as pea shape within a tight band; it is not a whole muscle in spasm.
- Painful on compression
- Palpation provokes a characteristic pain referral pattern
- Twitch response – firm perpendicular pressure applied over the trigger point can cause a local twitch response. This is caused by a transient contraction of the trigger point as pressure is applied.
- Jump sign – palpation of the trigger point can be exquisitely tender and cause the patient to jump.
- Regional persistent pain which is usually dull in character
- Reduced movement and strength in the effected muscle
- Possible tingling and numbness in the referral zone
- Postural muscles such as the upper Trapezius, Scalenes, Quadratus Lumborum and Gluteals are usually affected.
- Very little if any systemic symptoms
- No neurological deficit on examination
Trigger Point Treatment
They have been many methods identified for the treatment of trigger points, here at Morningside Chiropractic we focus on dry needling, deep tissue massage, myofascial release and inhibition-ischaemic compression technique. Other popular techniques include injections of a local anaesthetic or Boulinum toxin A and spray and stretch. All these methods work well and the decision of how to manage trigger points often comes down to the individual therapists experience, training and preference.
How does dry needling work?
Inserting a needle into an active trigger points helps to deactivate it and therefore decrease the pain that it is causing. It is not known exactly how it causes this effect but it is thought that it may disrupt the dysfunctional processes that are going on within the muscle and increase the local blood flow both of which will assist with tissue healing.
Inhibition-ischaemic compression technique
This has been identified as the one of the most effective manual therapies to deactivate active trigger points especially when it is combined with stretching techniques (Hanten, Olsen, Butts, & Nowicki, 2000). It involves the therapist identifying an active referring trigger point and applying direct pressure to it, this pressure is then maintained until the trigger point is felt to soften and the pain referral reduces which can take from a few seconds to a couple of minutes. The therapist will then repeat the process with increased pressure until they meet the next barrier of pain. The ischemia (lack of blood flow) which occurs as a result of direct pressure is thought to cause a reactive hyperemia (increase in blood flow) and return the site to normal conditions by removing the build-up of toxins and bringing in healing agents to the area (J.G. Travell & Simons, 1983).
A deep stroking massage is used along the length of the taut band (J.G. Travell & Simons, 1983). The pressure increases progressively with each successive pass along the muscle. This can be very tender but it relaxes the taut band, softens the trigger point nodule and in turn the trigger points becomes less tender and stops referring pain. This technique is thought to work in the same way as the inhibition-ischaemic compression technique (J.G. Travell & Simons, 1983).
Hanten, Olsen, Butts, & Nowicki (2000). Effectiveness of a home program of ischemic pressure followed by sustained stretch for treatment of myofascial trigger points. Phys Ther. 80(10):997-1003.
Travell & Simons’ (1983). Myofascial Pain and Dysfunction. The trigger point Manual.