A myofascial trigger point is a hypersensitive, palpable nodule-shaped point in the muscles. Trigger points can develop due to trauma, injury, inflammation or other factors. If the trigger point is painful at rest, it is called an “active trigger point”. If there is no spontaneous pain, there may be a hidden trigger point. In this case, the person’s range of motion in that area may be limited or the trigger point may cause muscle weakness.
When intervening in the trigger point, a small needle is inserted into the patient’s trigger point in the sensitive muscle and the anesthetic drug is injected into the muscle. This blocks the pain receptors in the nerves surrounding the muscle and reduces the pain signals sent to the brain. If steroid medication is used, it reduces inflammation and swelling of the tissue around the nerves, which can help reduce pain.
The drug-free injection may even provide mechanically independent benefits. The needle separates, relaxes and lengthens the muscle fiber, providing more pain relief. This approach is called “dry needling” and can be used in patients allergic to anesthetic medication. Some headache specialists perform trigger point injections in combination with peripheral nerve blocks in the same treatment session.
Pain treated with trigger point injections
Trigger points within the muscles of the head, neck and shoulders can spontaneously cause headaches. In addition, trigger points may be present in patients with migraine, tension-type, post-traumatic and other headache disorders and they may be aggravating or perpetuating factors for the underlying headache condition.
Otologic (ear) tinnitus, opthamologic (eye) strain, temporomandibular joint (TMJ) dysfunction and clenching can be treated with trigger point injections. Among the causes of shoulder pain, rotator cuff muscle tears, bursitis, adhesive capsulitis (frozen shoulder), tendonitis and impingement syndrome may benefit from trigger point injection. Lateral epicondylitis causing elbow pain may benefit. DeQuervain syndrome, carpal tunnel syndrome, degenerative joint disease and osteoarthritis causing hand and wrist pain can be treated with trigger point injection.
Lumbar degenerative disc disease, arthritic changes and herniated discs causing back and hip pain and degenerative joint disease or osteoarthritis causing knee pain can benefit from trigger point injections. Metatarsalgia and morton’s neuroma, plantar fasciitis (heel pain), acute and chronic tendonitis can benefit from trigger point injection treatment.
Athletic and sports-related overuse injuries and post-operative pain, post-traumatic injuries, motor vehicle accidents and myofascial pain can also be treated with trigger point injection.
