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 I J/cm2 and 5 J/cm2.
demonstrating the most significant effects (p < 0.001).
Only those subjects who had active laser treatment experi
enced 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
Key words: chronic pain, Visual Analogue Scal, LLLT, side
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