Twitch Response

Twitch Response or LTR, is a sudden contraction of fibers within a taut band when strummed (manually), needled, or compressed with a vibration massage device. The contractions may be observed visually, recorded electromyographically (EMG), or visualized with diagnostic ultrasound (1). This phenomenon is widely studied and utilized in the diagnosis of myofascial trigger points (MTPs), a common cause of muscle pain. The ability to induce LTR can also be used to differentiate MTPs from other types of muscle pain. 1. Gerwin, R. D., & Duranleau, D. (1997). Ultrasound identification of the myofascial trigger point. Muscle & nerve, 20(6), 767-768.