How Does it Work?
The therapeutic effects of laser only occur by stimulating the cells. Depth of penetration, wavelength, absorption by other tissue components, and energy dosage are all important (2). The greatest reduction in energy occurs at the level of the skin. Anything that prevents energy from reaching its target tissue (eg. skin, collagen, hair) will interfere with the therapeutic effect. Luckily, biological effects can be noted at low energy and once the skin is passed, penetration through muscle is much easier. So we can get deep penetration of tissues with relatively low power and low energy output (2)-and without shaving our patients!
The key message I’d like my readers to remember is that laser light directly stimulates energy production in the mitochondria of the cells (2)-high school biology/cellular respiration/Krebs cycle coming back to haunt anyone? This means that the effect of laser therapy will go on long after the treatment has stopped by improving the function of the cell, the strength of its membrane, and the quality of proteins it creates. In addition, laser stimulates DNA production, activates enzymes, accelerates tissue repair and cell growth in tissues (including nerves!), increases blood vessel development and improves circulation, promotes healthy immune responses, and reduces inflammation by affecting prostaglandins and inflammatory pathways similar to antiinflammatory medications and by increasing white blood cell activity (1,2,3). In addition to alleviating inflammation, laser reduces pain directly by decreasing nerve conduction, inhibiting pain receptors, increasing endorphins (the body’s natural pain relievers), and relaxing muscles and trigger points (1).