Achilles Tendonitis Causes and Prevention

Achilles tendonitis or Achilles Tendinosis which is probably a more accurate term to use in most cases is primarily and over use injury.

However, there are a number of factors which may pre-dispose the athlete to sustaining Achilles tendon injuries such as poor footwear, soft training surfaces, tight muscles and foot biomechanics and running uphill.

The Achilles tendon

The Achilles tendon is the large thick band of tissue at the back of the ankle which connects the calf muscles to the back of the heel and provides the pushing off force for walking and running. Tendonitis suggests an inflammatory condition of the tendon ('itis' means inflammation) but in reality few injuries are actually down to pure inflammation.

The main cause, particularly in older athletes is degeneration or wear and tear of the tendon. Other very similar conditions may actually be due to inflammation or degeneration of the tendon sheath which surrounds the tendon (called Tenosynovitis) rather than the Achilles tendon itself.

A number of factors make the athlete more likely to sustain an overuse Achilles tendon injury:

Foot biomechanics - If the athlete over pronates when running then this can cause the foot to flatten which in turn causes the lower leg to rotate inwards. If the lower leg rotates inwards this in turn twists the Achilles tendon which increases the stresses on it making it more susceptible for over use. A podiatrist can perform gait analysis to identify any biomechanical issues and correct them with orthotic inserts which are worn inside shoes, or for less sever cases advising on correct footwear for your running style.

Correct footwear - make sure you have the right running shoes for your foot type and the sport. Many specialist running shops will do gait analysis and have experience of advising the correct shoes. A worn out shoe or one that does not provide enough support can increase the strain on the achilles tendon. If you over pronate then you would probably be more suited to a 'motion control shoe' or a shoe with 'medial support'. This simply means that the mid sole of the shoe is harder on the inside that it is on the outside enabling it to resist rolling in or over pronating.

High heels - anyone who regularly wears high heels may cause the Achilles tendon to adaptively shorten over time. Then when they put their flat running shoes on the Achilles tendon may be stretching more than is normally comfortable increasing the likelyhood of injury.

Training - avoiding overuse and modifying training methods is important to prevent the injury from returning. For example running on soft surfaces, especially sand is not good for the Achilles tendon as it allows the heel to sink causing additional stretch on the tendon. If you are a runner then increase your weekly mileage gradually and by no more than 10% per week.

Uphill / treadmill running - if you regularly run uphill or on a treadmill which is set at an incline then this forces the Achilles tendon to working in a continually over stretched position, increasing the strain on it and therefore the likelyhood of sustaining an injury.

Prevention of Achilles tendonitis

 Premiership Physiotherapist Neal Reynolds talks to about preventing Achilles Tendonitis.


Achilles tendonitis can be prevented by understanding the possible causes of the injury and following these guidelines.

  • Gradually increase the duration and intensity of training.
  • Avoid training on soft surfaces such as grass or sand for long periods of time. The soft surface allows the heel to drop more, so placing more strain on the tendon.
  • Avoid wearing shoes that are too old.
  • If you overpronate, the Achilles is twisted putting more strain on it so ensure you wear the right training shoes or insoles.
  • Make sure you warm-up sufficiently before training.
  • Ensure that you stretch on rest days, as well as before and after training.

If you feel you have done just about everything right and still have ongoing problems you may need to see a Podiatrist and get a full biomechanical analysis to identify the cause.

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