ABSTRACT
One of the most important applications of low-level laser therapy (LLLT) is in the treatment of pain with a history commencing within a few years of the production of the first ruby laser in 1960 (Maiman 1960). Early clinical use related to laser acupuncture (LA) (Bischko 1980), where laser irradiation (LI) was applied instead of needles to single points identified by the principles of Traditional Chinese medicine (TCM) (Deng et al. 1987). Helium-Neon (He-Ne) laser devices were used almost exclusively for LA and were characterized by power outputs of less than 10 mW and energy densities (EDs) less than 4 J/cm2. As diode technology developed power outputs of laser devices used for pain increased from the original 1 mW devices to 1 W pulsed, defocused, ablative lasers such as Nd:YAG.
