Achilles Tendinopathy

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Aetiology (What is it?)

Achilles tendinopathy is an overuse injury to the Achilles tendon which connects the gastrocnemius and soleus (calf muscles) to the calcaneus (heel bone). The Achilles tendon is the biggest, strongest tendon in the human body. Micro-trauma in the Achilles tendon, may lead to stiffness and pain and in severe cases may lead to rupture of the Achilles tendon.

Pathophysiology (What’s happening?)

A continuum model has been proposed for Achilles Tendinopathy which is thought to consist of three stages:

Stage 1: Reactive tendinopathy – this initial stage is due to acute or chronic overload of the Achilles tendon above its physiological limit during training. This leads to microtrauma to the tendon which may result in inflammation and oedema.

Stage 2: Tendon Disrepair – if the tendon is not offloaded sufficiently (i.e. relative rest from the offending activity) the structural integrity of the tendon is compromised due to irregular collagen cross-linking which weakens the tendon.

Stage 3: Degenerative tendinopathy – abnormal collagen cross-linking leads to irreversible degeneration in the Achilles tendon, increasing risk of Achilles tendon rupture.

It is thought that the tendon can move up and down this continuum in the initial stages by increasing or decreasing load on the tendon. However, once degeneration has occurred it is permanent.

Achilles tendinopathy can be described as insertional or mid-portion, depending on where the pain is localised. Insertional Achilles tendinopathy occurs where the tendon inserts into the heel bone and mid-portion tendinopathy occurs in the tendon body (approx. 6cm up from heel bone).

The Achilles tendon has poor vascularity which leads to slow healing time.

Signs and symptoms

Morning pain in the Achilles tendon

Swelling and inflammation (in initial acute phase)

Usually pain will decrease with activity. For example, a runner may feel pain initially when first beginning the run, then the pain eases during the run. However, pain will usually  increase in the period post-run.

Risk factors

  • Obestiy

  • High blood pressure

  • Type II Diabetes

  • Overtraining or rapid increase to training load (overuse)

  • Local trauma to the tendon (sudden injury)

  • Hill climbing, stair climbing

  • Hard training surfaces

  • Tight and/or weak calf muscles

  • Pronation of the foot (pes planus)

  • Prolonged steroid use

Medical treatment options

During the acute phase where there is inflammation present, relative rest is advised with possible use of ice (10mins at a time) and anti-inflammatories for pain relief.

During the sub-acute and chronic phases it is advised to continue recreational activities with a decreased intensity/duration and within pain tolerance while rehabilitating.

Massage therapy and dry needling may be used to relieve muscle tension in the gastrocnemius and/or soleus muscles, thereby offloading the Achilles tendon. Dry needling may be used in the tendon itself to stimulate healing.

A physiotherapist may prescribe exercises for strengthening the calf muscles. Eccentric loading of the Achilles tendon by doing “heel drop” exercises has been found to be beneficial.

Stretches for gastrocnemius and soleus may be advised.

If conservative treatment fails, extracorporeal shockwave therapy may be used. In severe cases, surgery may be suggested.

 

References

Medina Pabón MA, Naqvi U. Achilles Tendonitis. [Updated 2020 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538149/

https://www.physio-pedia.com/Achilles_Tendinopathy

https://www.southerncross.co.nz/group/medical-library/achilles-tendonitis-tendinopathy