Video Clip 1: The Normal Activity of a Trigger Point

Needle electrodes are inserted into trigger points in the upper back of a woman and monitored on an electromyograph (EMG) that measures electrical activity in the trigger point. Electrical activity that can be seen on the monitor in the video clip is a measure of intrafusial activity, that when elevated over a period of time, causes increased pressure in the muscle spindle and leads to pain.

In the video clip, a needle electrode is inserted in tissue right beside the trigger point so that a comparison can be made between the electrical activity of the trigger point and the electrical activity of tissue immediately adjacent to the trigger point. On the left side of the screen, the electrical activity is clearly higher than in the adjacent non-trigger point tissue. This is an indication of why the trigger point tends to be tender or painful and the adjacent tissue is not. This video clip graphically illustrates the baseline level of electrical activity in both the trigger point and non-trigger point area.

Video Clip 1 (6.5MB - Quicktime movie)  |  Video Clip 1 (12MB - Mpg movie)
Video Clip 2 (6.5MB - Quicktime movie)  |  Video Clip 2 (12MB - Mpg movie)
Video Clip 3 (6.5MB - Quicktime movie)  |  Video Clip 3 (12MB - Mpg movie)