Considerations and Recommendations Regarding Myofascial Trigger Point Injection

Abstract

Objectives: The purpose of this article is to review the previously published data on myofascial trigger point injection and to present a proposed technique of myofascial trigger point [TrP] injection modified from tha described by Drs. Travell and Simons. Findings: Trigger point injection is an effective and valuable procedure to inactivate an active TrP, and subsequently relieve the pain and tightness of the muscle involved in myofascial pain syndrome. It is essential to elicit a local twitch response [LTR] during TrP injection to obtain the best results of immediate relief of pain. LTR is a brisk twitching of the muscle fibers of the taut band during mechanical stimulation [including needling] on the most sensitive site, the TrP region. Sometimes, other remote TrPs can also be inactivated if the "key TrP" is appropriately selected for injection based on skillfull clinical judgement. The trigger point injections are indicated for quick relief of acute, subacute, or chronic myofascial pain, for substitution of narcotic medicine, for restoration of functional impairment due to myofascial trigger points, or for supplementary therapy of chronic myofascial pain to facilitate its recovery. It is generally recommended to use 0.5% of procaine or lidocaine at a dose of 0.5-1.0 cc per TrP region for TrP injection. The proposed technique of TrP injection includes identification of the taut band containing the active TrP, skin preparation with sterile technique, rapid needle insertion into the multiple sites of a TrP region, injection of local anesthetic only if LTR is elicited, hemostatis, stretching and spray, and appropriate post-injection cares including cold or hot pack application, therapeutic exercise, therapeutic massage, and home program. The frequency and total number of injections should be determined based on clinical judgement. Some complications, such as muscle fiber damage, excessive bleeding, infection, syncope, or internal organ injury, may occur, but are usually preventable with careful and skillful injection technique. Conclusions: A technique of trigger point injection is proposed. Other than the traditional injection method, local twitch responses should be elicited as many times as possible during injection. The insertion of the needle should be quick to minimize muscle fiber damage. This technique is usually very effective to obtain immediate and complete pain relief.