Trigger Point Injections (TPI)
Sometimes when a muscle fails to relax, knots or tight “ropy” bands of muscle can form, creating extremely painful areas. These areas, which can often be felt under the skin, are called trigger points, and sometimes involuntarily twitch (or jump) when touched.
Trigger points are characterized as either active or latent. If active, they cause pain even when the body is at rest. If latent, they do not cause spontaneous pain but they may cause muscle weakness and restrict movement. Trigger point injections are used to treat active trigger points. The pain of active trigger points is “referred,” which means that while there is tenderness at the origin of the trigger point, the pain is felt in another area. This pain is often experienced as radiating or spreading.
There are various modalities for treating trigger points, such as physical therapy, ultrasound, and spray and stretch. If the trigger point does not respond to these treatments, usually because of a chronic condition, trigger point injection may be an effective treatment option. By injecting local anesthetic, the pain can be stopped at the trigger point.
Treatment is usually brief and multiple trigger points can be injected in a single session. A small needle is used and any experienced discomfort is similar to having blood drawn or an IV put in. After treatment, the patient may experience some soreness, bruising, or pain, but these reactions usually resolve within a few days.
The response to injection will depend upon the severity of the trigger point and the individual patient. The injection site will typically be numb for the first few hours, but for some patients, the injection can provide relief for up to one month.