Achilles Tendon

Recommendation:

Laser has been shown in several articles to help recovery in Achilles tendinitis e.g. Naterstad et al (2018) showed LLLT prevented hemorrhage, reduced inflammation severity, and preserved tendon morphology. They went further and said LLLT showed a significant superiority over commonly used anti-inflammatory pharmaceutical agents in acute collagenase-induced tendinitis.

In 2006 Carrinho et al. looked at the effect of laser on injured mouse tendons. The results are shown in the table below.

Treatment conditions	Tissue response compared to control tendons
Group A, tenomized animals, treated with 685 nm laser, at the dosage of 3 J/cm2	208% improved tissue response over control
Group B, tenomized animals, treated with 685-nm laser, at the dosage of 10 J/cm2	114% improved tissue response over control
Group C, tenomized animals, treated with 830-nm laser, at dosage of 3 J/cm2	167% improved tissue response over control
Group D, tenomized animals, treated with 830-nm laser, at dosage of 10 J/cm2	101% improved tissue response over control
Group E, injured control (placebo treatment)
Group F, non-injured standard control

As can be seen with lower dose laser therapy the tendons healed significantly quicker. However, higher doses lowered this improvement.

This and several other studies have been performed on experimentally induced problems and not in humans. 

In a review of the literature in 2020 Martimbianco et al. found only 4 articles suitable for inclusion in a meta analysis. Of those 4 (total 119 participants) they said there was low level evidence to support the use of LLLT in Achilles tendonopathy.

There is a definite discrepancy between experimental and known effects and the translation into human beings and day to day life. 

On balance LLLT has been shown to be effective on tendinitis. If the diagnosis in the Achilles is not that of tendinitis then LLLT may be of little to no value.