A trigger shot, or trigger point injection (TPI), delivers medication directly into specific, painful areas within a muscle. This treatment aims to alleviate localized discomfort, reduce muscle tension, and improve mobility and function for individuals experiencing persistent muscle pain.
What is a Trigger Point Injection
A trigger point is a hyperirritable spot located within a taut band of skeletal muscle fibers. These spots can be felt as palpable knots under the skin. When compressed, a trigger point can elicit local tenderness, a local twitch response, and often referred pain, meaning pain felt in an area distant from the actual spot.
A TPI involves inserting a small needle directly into an active trigger point. The injection typically contains a local anesthetic, such as lidocaine or bupivacaine, to numb the area and interrupt pain signals. Sometimes, a corticosteroid is added for longer-lasting relief by reducing inflammation. Saline solution is also used, and some techniques involve dry needling, where only the needle is inserted without any medication. The goal is to inactivate the trigger point, alleviating pain and relaxing the muscle.
Conditions Addressed
TPIs address various conditions characterized by muscle pain and tension. They are particularly beneficial for myofascial pain syndrome, a chronic condition involving painful trigger points in muscles and their surrounding fascia. This syndrome often leads to persistent muscle soreness, stiffness, and a reduced range of motion.
TPIs can also help manage tension headaches, which frequently arise from muscle tension in the head, neck, and shoulders, by targeting muscle knots in these areas to reduce pain. Fibromyalgia, a chronic condition causing widespread muscle pain and tenderness, may also be treated with TPIs to relax associated muscle knots. Other conditions that may benefit include low back pain, neck pain, and piriformis syndrome, where a trigger point in the piriformis muscle can press on the sciatic nerve, causing pain in the buttocks and leg.
The Injection Process
Before a TPI, the healthcare provider will carefully palpate the muscle to locate the specific trigger point(s) causing pain. The skin over the injection site is then cleaned with an antiseptic solution.
During the injection, a thin needle is inserted into the identified trigger point. Patients might feel brief discomfort or a muscle twitch, known as a local twitch response, which often indicates accurate needle placement. Multiple injections may be performed in one session, depending on the number of trigger points identified. After the injection, the needle is withdrawn, and the healthcare provider might apply pressure or have the patient gently stretch the treated muscle. The procedure is generally quick, taking only a few minutes, and is performed in an outpatient setting.
Important Considerations
While TPIs are generally considered safe, patients may experience common, temporary side effects. These include soreness, bruising, or mild tenderness at the injection site, which usually resolves within a few days. Some individuals might also feel lightheadedness or dizziness immediately after the procedure. Applying ice packs to the injection site can help minimize bruising and discomfort.
More serious complications are rare but can occur, such as infection, nerve damage, or, in uncommon cases, a pneumothorax (collapsed lung) if injections are given in the chest region. Patients with bleeding disorders, those taking blood thinners, or individuals with an active infection at the injection site may not be suitable candidates for TPIs. TPIs are typically part of a broader pain management strategy that may include physical therapy, stretching exercises, and other treatments.