Thermographic imaging of myofascial trigger points: a follow-up study.

Thermographic evaluation was performed on 11 adult volunteers with myofascial trigger points and on 11 asymptomatic controls. Infrared thermography was used to obtain a series of images to compare the sensory referral areas of myofascial trigger points with their thermal referral patterns. A series of images was then taken at, and distal to, the sensory referral area of each trigger point during quantitative compression of the trigger point, and dynamic temperature changes were monitored. Asymmetric thermal patterns were observed at all trigger points in the sensory referral area and distal to the referred area before compression. The thermal referral areas showed a reduction in temperature from precompression levels during compression. When similar but asymptomatic areas were compressed, no significant changes in temperature were noted at distal sites.