High Intensity Laser Therapy: How It Works
In every consultation, I am asked questions about high intensity laser therapy, such as how it works as a treatment and the science that makes high intensity lasers possible.
LASER is an acronym that stands for Light Amplification by Stimulated Emissions of Radiation. LASER is a concentrated narrow beam of light. Light can be described as both a particle and a wavelength (this is the part where I ask you to flip to page 97 of your physics book). Here are also two links that will help explain the early theories of light particles and waves:
Here we will explore wave theory to better grasp where LASER sits on the spectrum of light. Light wavelength is the measure of distance between the peaks of its waves.
Some wavelengths are harmful to the human body while others have a positive impact. At Midwest Pain Solutions, our LASERs are set up at 810 nm (nanometer) wavelength, which falls within the infrared spectrum (far left on the graph above). At a wavelength of 810 nm, the infrared LASER light penetrates and is absorbed by human tissue up to a certain amount. There is 100 percent absorption at skin level, and as the LASER penetrates deeper, the saturation percentage decreases. When you get through the skin, fat, muscle, tendon, and ligament, there is less available light for the nerve and joint complex to absorb, meaning you need a very powerful laser to effectively reach damaged deep tissue.
What happens when the LASER light reaches the tissues?
First, we must view the tissue as a large collection of the same cells. At the cellular level, there are structures that are made up of macromolecules (nucleus acid: DNA & RNA, lipids, proteins, and glycans) which are made of similar molecules (amino acids, fatty acids: unsaturated and saturated, phospholipids, long and short chain carbohydrates) that are grouped together. Those molecules are made up of atoms (*checks periodic table*) which consist of neutrons, protons, and electrons.
YAY! We now know all about cellular structure and what happens when LASER light is absorbed. “…infrared light excites cells through a novel, highly general electrostatic mechanism. Infrared pulses are absorbed by water, producing a rapid local increase in temperature. This heating reversibly alters the electrical capacitance of the plasma membrane, depolarizing the target cell. This mechanism is fully reversible and requires only the most basic properties of cell membranes.”
“Photobiomodulation by light in the red to near infrared range (630–1000 nm) using low energy lasers or light-emitting diode (LED) arrays has been shown to accelerate wound healing, improve recovery from ischemic injury.”
“Mitochondria are thought to be a likely site for the initial effects of light, leading to increased ATP production, modulation of reactive oxygen species and induction of transcription factors. These effects in turn lead to increased cell proliferation and migration (particularly by fibroblasts), modulation in levels of cytokines, growth factors and inflammatory mediators, and increased tissue oxygenation. The results of these biochemical and cellular changes in animals and patients include such benefits as increased healing in chronic wounds, improvements in sports injuries and carpal tunnel syndrome, pain reduction in arthritis and neuropathies, and amelioration of damage after heart attacks, stroke, nerve injury and retinal toxicity.”
What is the difference when comparing low-level/cold LASER to high intensity LASER?
Both types of LASERs are based on the same technology and science, but one is more powerful than the other. A LASER’s ability to penetrate depends on its wattage and how many cycles it can pulse every second. Cold LASERs (or low-level LASERs) are meant to penetrate no more than an inch into tissue and are available at almost all chiropractic clinics. Typical cold/low level LASERs have a peak power ranging between 500 milliwatts and 15 watts (1000 milliwatts per watt). These smaller LASERs may also pulse the beam into tissue 5-10 times a second. The pulsing of LASER allows for less heat to be distributed into the tissues, avoiding a burn. If you cannot pulse a LASER fast enough, too much heat will transfer to the surface layers and cause painful damage to the skin.
How can Midwest Pain Solutions run 500 watt LASERs?
We pulse the peak power of our high intensity LASER at 10,000 cycles per second using a very sophisticated computer system. This allows us to penetrate to the depth of tissue that is actually damaged. It’s an F1 race car vs. a Toyota Prius. It’s not in the same category.
Therapeutic laser therapy is aimed at stimulating healing changes within damaged tissues. Laser is an alternative to band-aid methods (like pain medication and injections) and can save some joints from needing surgery if there is still cartilage left. Midwest Pain Solutions has the most powerful therapeutic, high intensity lasers on the market, ready to help relieve some of your deep-tissue or joint pain.