Is that Achilles Tendonitis or Achilles Tendinosis?
Achilles tendinopathy or tendinosis is a relatively common condition that affects about 4% of the general population and up to 30% of competitive runners. The difference between tendonitis and tendinosis lays in the degree of inflammation and pathogenesis. Tendonitis is an acute injury from overload resulting in pain and inflammation. Tendinopathy or tendinosis is accumulated damage from chronic microtrauma, resulting in pain and stiffness with little or no inflammation. Tendinopathy is usually a failed healing response in an overworked tendon, but can also result from neuropathy or any sort of vascular disease that impedes blood flow, therefore impeding tendon repair.
How is Achilles Tendinopathy Treated?
Common treatments for achilles tendinopathy include eccentric exercise, glyceryl trinitrate patches, non-steroidal anti-inflammatory drugs (NSAIDs), and corticosteroid shots. Clinical studies evaluating the effectiveness of these treatments have shown little or no effect in the outcomes of patients prescribed NSAIDs or corticosteroid shots.¹ Which makes sense because inflammation is not a major issue in tendinopathy. Topical glyceryl trinitrate has shown some reduction in activity pain for patients also undergoing an exercise plan.¹ Though glyceryl trinitrate patches are not FDA approved for the treatment of tendon disorders, and without a standard dosage, effectiveness and side effects vary. While eccentric exercises have been shown to reduce pain especially when paired with the healing effects of photobiomodulation.²
Class IV Lasers Shown Effective to Treat Achilles Tendinopathy
A 2015 study that came out of the University of Otago in New Zealand, evaluated the combined the effects of photobiomodulation and eccentric exercise for treatment of Achilles tendinopathy. The authors wanted to investigate if they could implement fewer exercises while incorporating photobiostimulation with a dual wavelength 810/980 nanometer class IV therapy laser. This was a double-blind, randomized study; both participants and researchers were in the dark about who was receiving placebo or actual treatment. Eighty participants between 18 and 65 years of age with tendinopathy lasting longer than 3 months were enrolled and randomly divided into 4 testing groups (placebo + twice daily exercise, placebo + twice weekly exercise, laser + twice daily exercise, or laser + twice weekly exercise). Outcomes were measured with the Victorian Institute of Sports Assessment – Achilles (VISA-A) questionnaire. Statistically significant gains were found at the 12-week follow up for the group receiving twice weekly exercise with laser therapy.²
Infrared Laser Therapy and Achilles Tendinosis
When treating achilles tendinosis with near infrared laser, the therapeutic interaction takes place in the mitochondria of our cells. Photobiomodulation stimulates the Krebs cycle by dissociating the bond between Cytochrome C oxidase (CcOX) and Nitric Oxide (NO). Krebs cycle stimulation leads to increase ATP production, thus cells will have a store of energy to complete necessary metabolic processes. NO is synthesized in the body and plays an important role in many functions including vasodilation, blood flow, and platelet function.³ Once dissociated from CcOX, NO leads to vasodilation, allowing more blood flow to the affected area. Increased blood flow will allow the migration of tenocytes. Tenocytes are necessary to proliferate and synthesize the extracellular matrix that makes up the tendons in our body, thus repairing microtraumas associated with achilles tendinopathy.
Alfredson H, Cook J. A treatment algorithm for managing Achilles tendinopathy: new treatment options. Br J Sports Med. 2007;41(4):211-6. [NCBI]
Tumilty S, Mani R, Baxter GD. Photobiomodulation and eccentric exercise for Achilles tendinopathy: a randomized controlled trial. Lasers Med Sci. 2016;31(1):127-35. [NCBI]
Sarti P, Forte E, Giuffrè A, Mastronicola D, Magnifico MC, Arese M. The Chemical Interplay between Nitric Oxide and Mitochondrial Cytochrome c Oxidase: Reactions, Effectors and Pathophysiology. Int J Cell Biol. 2012;2012:571067. [NCBI]