If you’re currently spending the first ten minutes of every morning gingerly hobbling around the bedroom waiting for the back of your heel to loosen up, you’re in good company. It’s one of the most frequent complaints we see in the clinic, and it’s usually the dead giveaway that an Achilles tendon is struggling to keep up with your training.
What tricks many runners is that the pain often eases off once you get moving – or even midway through a run. But as soon as you cool down, or wake up the next morning, the stiffness comes right back, usually a little worse than before.
The natural reaction is to sit out for a few weeks or stretch your calves endlessly. But tendons are unique structures. Complete rest often makes the tendon even weaker and less tolerant to stress, which is why the pain frequently returns the moment you try to run again.
Getting over Achilles pain requires understanding why the tendon broke down in the first place, and progressively building its capacity back up.
What Is Actually Happening to the Tendon?
Your Achilles is the thickest and strongest tendon in your body. It acts like a high-tension spring, storing and releasing energy with every stride. When you run, it absorbs forces equal to several times your body weight.
When the demand on the tendon regularly outpaces its ability to recover, the tissue structure changes. Instead of neat, parallel collagen fibres that handle load efficiently, the tissue becomes disorganised and sensitive. We refer to this as Achilles tendinopathy (rather than “tendinitis”, as we now know it is rarely a simple inflammatory issue).
Depending on where you feel the discomfort, it usually falls into one of two categories:
- Mid-portion tendinopathy: Pain and thickening a few centimetres above the heel bone in the main body of the tendon. This is the most common form in runners.
- Insertional tendinopathy: Pain right where the tendon anchors into the back of the heel bone. This version requires a slightly tailored approach to avoid compressing the attachment point during rehabilitation exercises.
Why Has This Happened Now?
Tendon injuries are rarely caused by a single bad step. They are almost always the result of a shift in the balance between the load you are putting on the tendon and what the tissue can handle.
Common triggers we’ll see in include:
- Training spikes: Suddenly increasing your weekly distance, introducing hill efforts, or doing more speedwork without enough adaptation time.
- Footwear changes: Switching to lower-drop shoes or carbon-plated race shoes too quickly, which shifts more of the mechanical workload onto your calves and Achilles.
- Biomechanics and cadence: Overstriding or running with a low step rate increases the braking forces your lower legs have to absorb on impact.
- Calf strength gaps: If the calf muscles (the gastrocnemius and soleus) lack capacity, extra strain falls directly on the tendon structure.
How We Help You Rebuild: The Physio On The Green Approach
We don’t believe in telling runners to stop completely unless absolutely necessary, nor do we hand out generic exercise sheets. Our goal is to find your tendon’s safe working threshold, keep you moving where possible, and systematically rebuild your tissue resilience.
Here is how we approach Achilles rehab in the clinic:
Objective Testing with VALD ForceDecks
To manage tendon load properly, we need clear data rather than guesswork. We use VALD ForceDecks dual force plates to evaluate your lower-limb capacity. By measuring your calf raise, jumping and hopping, we can accurately pinpoint strength asymmetries between your legs, assess calf muscle output, and track how well your legs absorb impact force.
Diagnostic Ultrasound
Diagnostic musculoskeletal ultrasound allows us to assess your Achilles tendon in real time, providing valuable information about the structure of the tendon and the extent of any pathology. We can identify features such as tendon thickening, areas of degeneration, partial tears, and increased blood vessel formation (neovascularisation), while also ruling out other potential sources of pain around the ankle. Ultrasound findings are always interpreted alongside your symptoms and clinical examination, as structural changes do not always correlate with pain. When appropriate, ultrasound also enables us to monitor changes over time and ensure your rehabilitation is progressing as expected.
Running Gait Analysis
Because movement patterns play such a big role in Achilles stress, we often look at how you run on the treadmill. Using high-speed video analysis, we check for biomechanical factors- like heavy heel striking, overstriding, or low cadence – that might be overloading the tendon. Small adjustments to your technique can significantly reduce strain while you recover.
Progressive Tendon Loading
Tendons adapt best when loaded systematically. We tailor your exercise parameters to your specific recovery stage – using isometric holds to settle pain, progressing to heavy slow resistance (HSR) and heavy eccentrics to rebuild tissue capacity, and finally introducing dynamic plyometrics to restore the elastic “spring” your Achilles needs for running.
Shockwave Therapy (ESWT)
For stubborn or chronic cases that haven’t responded to load management alone, Extracorporeal Shockwave Therapy (ESWT) can be an excellent addition. Shockwave delivers targeted acoustic waves into the affected tissue to help reduce local pain, increase circulation, and restart the body’s natural healing response in stagnant tendon tissue.
The Takeaway
Achilles tendinopathy can be frustrating, but with a structured, data-driven loading plan, tendons adapt and heal remarkably well. If you’re dealing with persistent heel stiffness or pain that’s disrupting your training, getting an accurate assessment is the first step toward running freely again.
Ready to get back to running pain-free? Book an initial assessment or running analysis with our clinical team today.
Written By Chris Croker | Clinical Manager | Specialist Physiotherapist
References
- Cook, J. L., & Purdam, C. R. (2009). Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. British Journal of Sports Medicine, 43(6), 409-416.
- Mani-Babu, S., et al. (2015). The effectiveness of extracorporeal shock wave therapy in lower limb tendinopathy: a systematic review. The American Journal of Sports Medicine, 43(3), 752-761.
- Silbernagel, K. G., Hanlon, S., & Willy, R. W. (2020). Current Clinical Concepts: Conservative Management of Achilles Tendinopathy. Journal of Athletic Training, 55(5), 438-447.