E Liisa Laakso Carolyn Richardson, and Tess Cramond
1: Physiotherapy Department, Royal Brisbane Hospital, Brisbane; 2:
Physiotherapy Department, University of Queensland, Brisbane; and 3: Pain
Clinic, Royal Brisbane Hospital, Brisbane, Queensland, Australia.
Clinically, Low Level Laser Therapy - LLLT has been used successfully in
the treatment of chronic pain but many have questioned the scientific basis
for its use. Many studies have been poorly designed or poorly controlled. A
double-blind, placebo-controlled, random allocation study was designed to
analyse the effect of second daily infrared (JR) laser (820 nm, 25 mW) and
visible red laser (670 nm, 10 mW) at 1 J/cm2 and 5 J/cm2 on chronic pain.
Forty-one consenting subjects with chronic pain conditions exhibiting
myofascial trigger points in the neck and upper trunk region underwent five
treatment sessions over a two week period. To assess progress, pain scores
were measured using visual analogue scales before and after each treatment.
The incidence of side effects was recorded. All groups demonstrated
significant reductions in pain over the duration of the study with those
groups which received infrared (820 nm) laser at 1 J/cm2 and 5 J/cm2.
demonstrating the most significant effects (p < 0.001). Only those subjects
who had active laser treatment experienced side effects. Results indicated
that responses to LLLT at the parameters used in this study are subject to
placebo and may be dependant on power output, dose and/or wavelength.
Key words: chronic pain, Visual Analogue Scal, LLLT, side effects,
phototherapy.
Addressee for Correspondence: E Liisa Laakso BPhty PhD, Physiotherapy
Department, Royal Brisbane Hospital, Herston, (Queensland, Australia, 4029.
6/97 Rep. US $8-10-12 copyright 1997 by LT Publishers, , U.K.' Ltd.
Manuscript received: January, 1997 Accepted for publication: March, 1997
LASER THERAPY. 9: 67-72 67
Two wavelengths studied.
Best results with the higher powered infrared laser compared with the lower
powered red laser
