Effects of the infrared laser therapy at treated and non-treated trigger points

Acupunct Electrother Res. 1989;14(1):9-14. doi: 10.3727/036012989816358560.


For reliability of the pain threshold measurement there were measured first 390 trigger points of 22 healthy students twice at each point. The reliability of two different measurements was found to be perfect. Infrared (904 nm) laser therapy was compared to placebo laser at the trigger points. Our study tested eighteen patients (11 men and 7 women), with 31 active trigger points in the muscles of the infraspinatus, extensor carpi radialis, levator scapulae, trapezius and tibialis anterior. Trigger points were randomly managed by infrared laser (dose 1.5J/point and place laser. The study was carried out by double-blind and cross-over principle. The responses of the management were documented by the pain threshold meter measurements of these trigger points before and after the treatments, and then fifteen minutes later. The trigger points of the other side of the body were also measured from the same muscles. In the results there were observed highly significant changes between the laser and placebo groups immediately after the treatment, 0.97 (SE 0.16) kg/cm2 (p less than 0.001). The differences between these two treatments were greater after fifteen minutes of the therapy--1.87 (SE 0.30) kg/cm2 (p less than 0.001). At the non-treated trigger points, the significant increase of the values was seen after fifteen minutes (p less than 0.05). Our research study results suggest that infrared laser had an effect at the trigger points and that the treatment significantly increased the pain threshold.

MeSH terms

  • Adult
  • Female
  • Humans
  • Infrared Rays
  • Laser Therapy*
  • Male
  • Myofascial Pain Syndromes / therapy
  • Pain / physiopathology*
  • Pain Measurement