Achilles tendon injuries are one of the most common issues we see in the clinic. Tendons are incredibly sensitive to load, and especially sudden changes in load, whether that be a rapid increase in running volume or certain biomechanics that repeatedly overload one specific area.
What makes our lives difficult is that tendons need to be exposed to load to strengthen, adapt and become more robust. However too much, too quickly, and we risk overload and injury. Managing this exposure to load can be difficult, there is no one size fits all. What one runner might be able to tolerate, another runner might not.
What is an achilles tendinopathy?
A true Achilles tendinopathy is a disorder of the tendon, that research has shown is not in-fact inflammatory in nature, but rather a failed response of the tendon to a sudden increase in load with a resulting increase in protein, water, blood vessels and nerves within the tendon. These tend to occur over a period of days or weeks, rather than occurring suddenly, and tend to be driven by training errors or biomechanical issues that may have been present some weeks prior to the onset of pain.
The Achilles tendon attaches the calf muscles (made up of the soleus and gastrocnemius muscles) to the heel bone, transmitting forces through the foot and ankle at push off, as well as controlling motion of the ankle and knee as we move through the phases of gait. The Achilles is exposed to huge loads when running - roughly 5.2x body weight.
Achilles tendinopathy symptoms
Tendons are in a constant state of damage, repair, and regeneration - it's how our tendons get stronger. If the amount of tissue damage and breakdown is greater than the speed of regeneration you run the risk of overloading the structure and developing a tendinopathy. This can be seen on a continuum of three stages:
If you do experience sudden, sharp, pain in the Achilles, whilst running, with no pre-warning there is likely significant tissue damage. This is not a tendinopathy. Do not try to run on this. Rest and seek expert advice.
Tendon management is an on-going process that must be continuously monitored, especially when returning from injury.
I advise my runners to keep a diary to monitor the symptoms and behavior of the tendon. With tendons, and especially the Achilles, you may often feel fine during your run, however the next morning, you find yourself hobbling about - monitor the 24-hour symptoms! If the soreness or stiffness worsens within this period, you are simply doing too much. Ease things back until symptoms are more manageable.
How to treat an Achilles Tendinopathy?
Advice and exercises will vary on several things:
Reduce the load
Do NOT stretch
Strengthening
To increase the tolerance of the tendon to load we need to gradually expose it to increasing amounts of load*. This can be done in the form of a variety of heel raise type exercises, depending on the severity of your Achilles tendinopathy:
* Throughout these exercises I would allow some awareness in the Achilles area, however no more than a 2-3/10 on the pain scale and no worsening of your symptoms after performing them.
1. Isometric heel raise - perform with the knee both bent and knee straight
From the floor or over the edge of a step, raise up onto tip toes so that you are roughly 50% of the way up. Transfer your weight onto the effected leg and hold this position.
- Hold for 10-15 seconds
Repeat this 5-6 times, 1-2 times daily
As symptoms settle work towards 30-45 seconds
Repeat this 3-4 times, 1-2 times daily
Progress from body weight to adding in some external weight as able. Start with 5kg and increase weight from there - 15-20kg is a good aim
These are suitable for mid-portion Achilles injuries in the reactive tendon stage
From the floor or off the edge of a step (harder!) raise up onto tip toes. If performing the double leg raise transfer all your weight onto the effected leg and then slowly (3-5 seconds) lower your heel towards the ground.
- Perform 12-15 repetitions -body weight
Repeat 3 times, once daily
As symptoms settle, I would look to increase the amount of resistance whilst reducing the number of repetitions, for example:
10 repetitions, 3 sets with 10kg
These are suitable for mid-portion Achilles injuries in the less acute, tendon dysrepair and degenerative tendon stages.
As with the running you must monitor your symptoms once you initiate these exercises. No deterioration in your symptoms immediately after or within the 24-hours following.
My prescription for repetitions, sets, weight, and frequency would be individual based, depending on current volume of running and the extent of the Achilles tendinopathy.
Should you run?
Three simple tests to determine if you should continue to run with your sore Achilles:
1. Can you walk pain free?
No - rest
Yes - move onto the next test
2. Can you heel raise 20x pain free?
No - rest
Yes - move onto the next test
3. Can you perform 10-15 single leg hops?
No - rest
Yes - try a short run, 5 minutes initially or 5x 1min on, 1min off.
Monitor your symptoms over the next 24-hours and progress from there
What causes an Achilles tendinopathy?
Training errors
Biomechanics
Biomechanics is all to do with how we move. When assessing someone's biomechanics we are looking at how the various structures of the body are moving in relation to one-another and how are they interacting with the ground.
Certain biomechanics have been shown to increase our likelihood of developing certain lower limb type injuries:
Other types of Achilles tendon injury
We must also be aware of some other conditions that can exist around the Achilles tendon. The insertion point of the Achilles tendon into the heel can cause issues - insertional Achilles tendinopathy. Pain here will present at the attachment of the tendon into the heel bone, rather than the mid-portion of the tendon. In this area you can also develop inflammation of what's known as the retrocalcaneal bursa - a small sac of fluid that sits between the Achilles tendon and the heel bone to reduce friction.
Achilles tenosynovitis is an inflammatory conditioning affecting the sheath that surrounds the Achilles tendon. Although similar in nature to the Achilles tendinopathy these may often worsen with activity, even biking, rather than easing.
If you have a particularly bony heel, especially on the outer part you may have a Haglund's deformity. This can be genetic or a response to loading. Due to the location of the Haglund's once irritated they can be difficult to settle as with each step the extra area of bone nestles into the back of the Achilles tendon, further causing pain. For these please seek advice and do not continue running or pushing on with exercises through pain and discomfort.
Treatment, advise and exercise prescription for the above issues will vary from that of the Achilles tendinopathy so I would recommend seeking expert advice before trying to manage things yourself.