Light therapy is being used to treat a variety of painful conditions of the soft tissues and joints. Light or photon energy can be used to increase local cellular metabolism without risk of tissue damage.
"It is suggested that lasers utilize photon energy as a catalyst. Evidence indicates that cells absorb photons and transform their energy into adenosine triphosphate (ATP), the form of energy that cells utilize. The resulting ATP is then used to power metabolic processes; synthesize DNA, RNA, proteins, enzymes, and other products needed to repair or regenerate cell components; foster mitosis or cell proliferation; and restore homeostasis. When healing appears to be impaired, evidence suggests that low energy laser speeds many stages of healing. It accelerates inflammation, promotes fibroblast proliferation, enhances chondroplasia, upregulates the synthesis of type I and III procollagen, fosters revascularization of wounds, increases hyperemia of treated tissues, and overall accelerates tissue repair. Laser therapy can modulate pain through its direct effect on prostaglandin levels, alteration of somatosensory evoked potential and nerve conduction velocity." ("Therapeutic Light," Chukuka S. Enwemeka, PT, PhD, FACSM, "The Photo Biological Basis for Low Level Laser Therapy," Kendric C. Smith).