Achilles Tendinitis, or Achilles Tendinopathy, is a prevalent and often debilitating injury among runners. In this blog, we delve into the underlying causes of Achilles tendon injuries, providing insights into how they occur. We will also explore effective strategies for understanding, managing, and preventing this injury, empowering you to maintain your running performance and overall foot health.
What is Achilles Tendinitis?
The Achilles tendon is the largest and most robust tendon in your body. It runs down the back of your lower leg, attaching the calf muscles (gastrocnemius and soleus) to the heel bone (calcaneus), allowing you to flex your ankle and facilitate activities like walking, running, and jumping. You might hear it called Achilles tendinitis or tendinosis, but these terms essentially refer to the same condition.
What Causes Achilles Tendinitis?
Achilles tendiniitis occurs when the tendon struggles to adapt to the strain placed upon it, leading to repeated micro-damage within the tendon fibres.
1. Overuse and Repetitive Strain:
Running, particularly long distances or at high intensities, places significant stress on the Achilles tendon. Overuse without adequate rest can lead to micro-tears and inflammation, eventually resulting in tendinopathy.
2. Poor Footwear Choices:
Wearing inappropriate or worn-out running shoes can exacerbate stress on the Achilles tendon. Transitioning from shoes with a high drop height (the difference in height from the heel to the forefoot) to those with a low drop height increases the strain placed on the Achilles tendon. Without an appropriate transition period, this change can lead to tendon overload. Another footwear-related cause is the addition of carbon-plated shoes. The added compression and recoil from a carbon-plated shoe, combined with a lack of knowledge on how to safely introduce them into your rotation, is a common issue we see in the physio clinic among runners presenting with Achilles Tendinopathy.
3. Biomechanical Issues:
Over-striding and increased knee flexion during the mid-stance phase of the gait cycle can significantly influence the development of Achilles Tendinopathy. Over-striding, where the foot lands too far in front of the body's centre of mass, increases the braking forces and places additional stress on the Achilles tendon. Similarly, excessive knee flexion (knee moving over toes) in mid-stance adds excessive forces through the Achilles tendon. These biomechanical
inefficiencies can accumulate over time, causing microtrauma and inflammation in the Achilles tendon, ultimately contributing to the development of Tendinopathy.
4. Sudden Increase in Training Intensity:
Rapidly increasing your pace, distance, or frequency of your running sessions without allowing your body to adapt can overload the Achilles tendon. This sudden surge in activity is a common trigger for Tendinopathy among runners. You can understand this better by looking back at your training log.
Signs & Symptoms
Morning Pain & Stiffness: This is a hallmark sign of Achilles Tendinopathy. Stiffness around the tendon upon waking usually eases after a few minutes of walking. As the tendon continues to get irritated, the morning stiffness may persist throughout the day or become more pronounced at the end of the day. Stiffness may also be present after long periods of sitting (such as desk-based work).
Tenderness: The tendon is tender to touch either at the insertion around the heel bone or in the middle of the tendon. The location of the tenderness impacts how the tendon responds to loading and rehab. In some irritated tendons, there may be a lump due to excessive swelling as your body tries to repair the tendon.
Pain with Running: Similar to morning pain, symptoms during running behave in a similar manner. In the early stages, pain is present at the start of the run but settles within 5-10 minutes. Pain typically arises 1-2 hours after the run and/or the next day. As symptoms persist, a runner will start to experience pain either during the run or at the end, with continued pain after running and the next day. Achilles tendons are typically more sensitive to increases in pace (such as a tempo or interval session).
Inability to Hop or Heel Raise: In milder cases, the tendon may only be sensitive to hopping. As the tendon continues to be overloaded, performing heel raises (single and/or double leg) can start to become difficult and painful.
To better understand how you can self-assess your tendon, you can follow the tests in this video:
Self-Management Strategies
Rest: Rest is by far the most talked about and misunderstood topic when managing Tendinopathies. As a general rule, rest (no running or loading) is typically not a solution for Tendinopathies. Rest needs to be relative to the level of loading your tendon can manage. This could mean the runner may require rest from running but still be able to load with exercise. Or the runner may load concurrently with a reduction in running load. This balance of rest and rehab needs to be carefully tuned to the individual.
Training Load: Addressing training load is critical in allowing the tendon adequate rest to repair. In the early stages, pausing fast runs like interval and tempo runs and avoiding back-to-back run days are great ways to reduce load while still keeping some load that the tendon can handle. As tendons continue to be irritated, runners may need to progressively reduce run days, leading to rest from running and potentially a reduced daily step count. As the Achilles builds strength with rehab (exercises), runners can progressively start to add more time or days, followed by adding pace back into runs. Monitoring symptoms during and after runs, coupled with slow increments in training load, is crucial to ensuring the Achilles tendon adapts positively to rehab.
Footwear: Wearing shoes with higher drop heights or heel lift inserts can significantly reduce symptoms. This is because the increased height of the heel to the forefoot reduces strain on the tendon. Additionally, temporarily pausing the use of carbon-plated shoes is recommended as these add load to the tendon as mentioned above.
Exercise Rehabilitation: Research has shown that tendons respond best to heavy stimulus. The aim of a good rehabilitation programme should be to progressively increase the amount of weight you add to loading the tendon during exercise and reduce the volume of repetitions to maximise adaptation and minimise overload. Heel raises are the simplest and most effective way to load the tendon. Early loading for some runners might be limited to heel raise holds, either single or double leg. As the tendons respond positively to the exercises, runners should add more weight before introducing heel raises.
Following this, look to add in slow-moving heel raises, either double-leg variations into single-leg exercises that you would progressively load by adding a step and additional weight. As the tendon begins to tolerate higher levels of being loaded (i.e. single-leg raises on a step), runners should look to add in plyometric (landing and jumping) exercises to build a stiffer, stronger tendon. The primary aim when performing plyometrics is to be spring-like off the ground and minimise the time spent making contact with the ground, followed by the height of the hops.
Pogo hops are a great exercise; runners should start with double-leg variations from low height to high explosive hops, followed by single-leg variations in a similar manner. It’s important to ensure plyometrics are performed at a low volume (low reps).
Achieving optimal rehabilitation requires careful implementation of all the factors mentioned above, all working in harmony with each other.
Remember, Achilles Tendinopathies don’t always play by the rules. Listen to your body, always seek professional guidance, and prioritise your rehabilitation.
For expert help and management please feel free to contact my team at The Running Room (www.therunningroom.net)