How Do Trigger Points Work?
Trigger points are hyperirritable local points within a taut band of muscle or in the fascia of the muscle. The trigger point is painful to compression and palpation. It can produce a characteristic referred pain, local tenderness and autonomic phenomena (Travell and Simons 1992).
The goal of trigger point dry needling therapy is to desensitize supersensitive structures, to restore motion and promote comfortable muscle function. It is possible that it induces a healing response in the muscle or tendon tissue by producing a local inflammation. It decreases spontaneous electrical activity at trigger points.
The mechanical effect of TPDN is disruption of the integrity of the dysfunctional motor end plate. It may provide a localized stretch to the contracted cytoskeletal structures by rotating the needle. Moving the needle up and down may cause a needle grasp and a resultant local twitch response. The local twitch response may use up acetylcholine (neurotransmitter) in the tissue which was triggering increased firing.
Baldry (2001) suggests that TPDN may stimulate A-nerve fibres for as long as 72 hours after needle insertion. This may activate the enkephalinergic inhibitory dorsal horn interneurons to cause opioid mediated pain suppression. It may also active descending inhibitory systems to block noxious stimulus into the dorsal horn.
Shah (2001) noted that the increased levels of chemicals such as bradykinin (vasodilator) and Substance P (a neurotransmitter and neuromodular) found in the trigger point are immediately changed with a local twitch response during trigger point dry needling therapy.
TPDN causes microtrauma with microbleeding and therefore the release of platelet-derived growth factor into the local tissues to produce inflammation and healing.
Trigger Point Dry Needling Therapy
If you can palpate a trigger point you can needle it. Anatomical knowledge of structures is vital to prevent injury to structures which could be needled inadvertently. For example, in treating the rib cage area techniques are learned so that the lungs remain untouched by the needle. In many needling techniques bones are used as a backstop. In other techniques, the muscle is pinched and needled through. In other cases, the needle length and angle are chosen to avoid structures that should not be needled. In all cases, needling is the skillful placement and manual handling of the needle in the trigger point to obtain the desired “release” of the trigger point. What we like the most about trigger point dry needling therapy is that the results are immediate.
If a patient is uncomfortable with the thought of needles, we don’t use them. We never talk anyone into dry needling. We offer it and explain it. If they seem comfortable with the idea of using needles, we start with a few points at first and do more on subsequent visits. For example, with a headache patient, we needle the occipitalis, suboccipitals and C2 and then stop (6 points). Usually, they ask for TPDN the next visit. Then, we will add the upper traps and lev scap or whatever other trigger points are found.
Common Areas for Trigger Point Dry Needling Therapy
- The suboccipital area and cervical spine for headaches and neck pain
- The scapular area, especially the levator scap, upper trap, teres and rhomboids
- The lumbar paraspinal muscles and the quadratus lumborum
- The piriformis and gluts
- The ITB and Vastus lateralis
- Medial and lateral epicondyles—needling the bone and tendon for microtrauma (also the points in the extensors)
- Gastrocnemius, peroneals, post tib
- Achilles (needling the tendon for microtrauma)
- The whole shoulder area
- Hip adductors/high groin sprains