As a pain specialist I treat all kinds of pain from neck pain and back pain and sciatica, to complex regional pain syndrome (CRPS), to post-surgical pain syndrome. Headaches are common, but perhaps the most common type of pain to treat are tender points, knots or painful spots on the body, which some call trigger points.
What are trigger points?
Trigger points are irritable spots that can appear like a small lump in the muscle. Pressing on it or activating the muscle group can cause pain over the area, or even pain elsewhere in a phenomenon known as ‘referred pain’. This referred pain does not always follow the pattern of nerve sensation or skin mapping or muscle group.
The pain syndrome from trigger point, also known as a ‘pain map’ is constant and reproducible. A person with trigger point will have the same pain map day to day with minimal variation.
Pressing on a trigger point can lead to what is known as a ‘jump sign’ where patients are startled by the pain and wince and cry out. This is completely out of proportion to the amount of pressure applied. Patients with triggers points also experience involuntary movements such as jerking of the head, neck or limb away from the trigger point that is being pressed.
A person with two or more trigger points may have something called ‘myofascial pain syndrome’ which is an area of irritability in the muscle and the muscle covering known as ‘fascia’.
Causes of trigger points
- Overuse of muscle: activities like High intensity training (HITs) lead to microtrauma in muscles and trigger points
- Lack of exercise
- Getting older: trigger points tend to affect people between the ages of 30-55
- Poor posture
- Stress and associated illnesses such as anxiety, depression and post-traumatic stress discorder
- Poor sleep: healing of microtrauma in muscle occurs during sleep. Interrupted sleep leads to less growth hormone and poor healing. The accumulation of microtrauma in muscles then lead to the formation of trigger points
- Vitamin deficiencies in Vitamins B, C, D as well as folate and iron
There are various theories as to why trigger points and tender points arise, although researchers don’t fully know.
- Radiculopathic theory:
- nerves behave abnormally because of pressure from a bony spur, herniated disc or other trauma. This leads to trigger points in the areas that is controlled by these nerves
- Sensitization theory:
- in this phenomenon, prolonged or intense pain leads to changes in the nerves that carry the pain signals, as well as the nerves that relay these pain signals up the spinal cord to the brain. This leads to hypersensitivity in the affected area
- Polymodal theory:
- Polymodal receptors exist throughout different muscle group that has the propensity to turn into trigger points under the right conditions
- Integrates trigger point hypothesis
- This is the most likely reason why there are trigger points.
- Overactivity of the muscles leads to changes in the muscle cells. This leads to inflammation, loss of oxygen and nutrient supply, shortening of muscle fibres and increased metabolic demand.
- All these leads to creation of an abnormal area of muscle known as a trigger point
Treatment of trigger points
Simple medications should be tried first, following which the other therapies can be tried. Although the various treatments are effective, possibly only pain procedures (i.e. radiofrequency procedures) produce longer lasting results because they address the underlying issues that produce trigger points/tender points in the first place. The radiofrequency procedures are different from the ones where probes that are simply placed over the skin.
- NSAIDs or COX 2 inhibitors like ibuprofen, diclofenac, arcoxia, celebrex can be tried
- muscle relaxants can be tried for a short term
- weak opioid like tramadol can be tried for a short period
- strong opioids are reserved for pain crises and should not be used in most cases
- Physical therapy
- posture training
- spray and stretch
- cold and hot packs
- Laser light therapy
- Transcutaneous Electrical Stimulation
- Pain procedures:
- trigger point injection: injections with local anaesthetic or dry needling can be performed, although there is mixed evidence
- radiofrequency procedures: usually done under some sedation, these place needles near the affected nerves, or facet joints in order to deal with the underlying problem such as referred pain from a painful facet joint, or an abnormal and irritated nerve root
- growth factor injections: use of biologics in regenerative medication to address the problem at the level of the muscles is an area of ongoing research that is promising but not fully established