Laser Therapy Effects on Joint Pain And Inflammation

Low-level laser therapy (LLLT) is a non-invasive, pain-free, light-based therapy that uses red and infrared light to target inflamed, injured, and diseased tissues. It is especially great for reducing inflammation, pain, and edema in damaged joints. LLLT does this by inducing an analgesic effect by disrupting axonal transport in small diameter fibers. Repeated treatments have been shown to lead to a significant reduction in central sensitization or hypersensitivity of the central nervous system due to chronic pain.

The science behind it:

LLLT targets an enzyme called Cytochrome C Oxidase which is found in the mitochondria of cells, the organelles that are responsible for cellular metabolism and giving the cell energy in the form of ATP. The absorption of light by Cytochrome C Oxidase (along with other molecules such as oxygen) activates the oxidative respiratory chain, the chemical reaction that allows the mitochondria to produce the ATP.

In the inflammatory process, there is an increase of nitric oxide which binds to the Cytochrome C Oxidase and competitively decreases oxygen resulting in a decreased amount of oxygen to be used by the cells. In LLLT, the light is absorbed by the Cytochrome C Oxidase and displaces the nitric oxide so the oxygen can be used to produce ATP. The cell’s metabolism is improved and inflammation slowly decreases resulting in a reduction of joint pain and inflammation.

How laser light therapy heals the cells:

LLLT increases the amount and functionality of macrophages and neutrophils, which remove damaged cells and breaks the cycle of chronic inflammation. It also decreases the amount of oxidative stress around the joint which promotes cell survival and reduces cellular damage. Anti-inflammatory cytokines are increased in response to light therapy and prevent the stalling in the inflammatory phase and promote tissue repair. There is also a decrease in pro-inflammatory cytokines and prostaglandins which results in decreased pain.

The evidence:

In a meta-analysis compiling 16 different clinical trials of neck pain, LLLT was shown to reduce pain immediately after treatment in acute neck pain and with up to 22 weeks of relief for chronic neck pain sufferers after a completed program.

Another study using lab rats induced with rheumatoid arthritis concluded that LLLT is able to modulate the inflammatory response both in early as well as late progression stages of RA.

Osteoarthritis of the knee was studied resulting in findings showing significant improvement of joint flexion with lasting results as well as less pressure sensitivity of the joint. Thermographs showed higher temperatures due to increased microcirculation around the knee (improved due to angiogenesis).