Some of the data in this article is taken from http://pain6.blogspot.com/2009/10/trigger-point-needling-to-alleviate.html
Trigger Point Needling is a commonly used method to alleviate pain from trigger points, which are knots or hardening of muscle fiber. The procedure is generally performed by a medical doctor or osteopath and can be either in the form of dry needling or the doctor may inject a pain killer such as lidocaine or even botox into the trigger point to ease the patient's pain.
Injecting lidocaine into a trigger point is very similar to getting any type of injection, except that with a trigger point injection, the doctor wants the medicine to reach a specific area in a specific muscle as opposed to the medicine generally entering the patient's system.
Lidocaine "is widely used for infiltration, nerve-block, and spinal anesthesia in a 0.5 to 2 percent aqueous or saline solution and is also applied to mucous membranes (2 to 4 percent) for mucosal anesthesia." (1) Because lidocaine is a fast acting anesthetic, pain relief may be almost immediate depending upon the reason for the trigger point flareup.
According to Dr Janet Travell, "trigger point injection requires careful positioning of the patient and often needling at both the central and attachment trigger point regions to be successful." (2) After trigger point injection the physician will also usually prescribe several visits to a physical therapist for "bimanual release of tightness in the vertical and diagonal muscle fibers" (3) of the muscle immediately surrounding the trigger point.
In addition the physical therapist will also prepare the trigger point for manipulation by either icing down the trigger point and surrounding muscle or applying a vapocoolant spray over the muscle and painful areas prior to manual manipulation.(4) The goal of both the injection and the physical therapy is to coax the trigger point to relax its tight grip on the muscle.
Figure 1 shows a perpendicular injection into a trigger point, which is the injection into the central area of the trigger point that was previously mentioned. Figure 1 also shows a similar injection into the trigger point at an angle in the inset picture. Many physicians will inject straight in and at angles to the right and to the left to insure reaching all areas of the trigger point needed to ease the patient's pain.
Botox, or Botulinum Toxin Type A, is injected in a similar manner that lidocaine is injected. Botox is a drug developed from a toxin produced by the bacterium Clostridium botulinum, which is the same toxin that causes food poisoning or botulism. (5)
Trigger Point Needling and Chronic Pain