Achilles tendinitis is a common overuse injury that affects the Achilles tendon, the large tendon connecting your calf muscles to your heel bone. This tendon is responsible for pushing off when you walk, run, or jump, and when it's overloaded or strained repeatedly, it can become irritated, inflamed, and painful. Left unchecked, it can progress to more serious tendon damage.
The pain typically shows up at the back of the ankle, just above the heel. It might start as a mild ache after activity that gradually becomes more persistent. Mornings are often the worst, with stiffness and pain when you first stand up. As the condition progresses, you may feel pain during activity, not just after. The tendon may become tender to the touch, and you might notice swelling or thickening along the back of your ankle. Some people also experience weakness when pushing off or going up on their toes.
Achilles tendinitis doesn't always announce itself right away. Many people push through early discomfort, only to find the problem worsens over time. What starts as minor soreness can turn into debilitating pain that limits your ability to walk, run, or participate in activities you enjoy.
What Causes Achilles Tendinitis?
Achilles tendinitis develops when the demands placed on the tendon exceed its capacity to adapt and recover. Common causes include:
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Sudden increases in training volume, intensity, or frequency, especially in running or jumping activities
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Repetitive stress from high-impact sports like running, basketball, soccer, or tennis
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Tight or weak calf muscles that place extra strain on the tendon
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Poor ankle mobility or biomechanics that alter how force is distributed
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Running on hard surfaces or uneven terrain
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Worn-out or inappropriate footwear that doesn't provide adequate support
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Hill running or speed work without proper conditioning
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Returning to activity too quickly after a period of inactivity
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Age-related changes that reduce tendon elasticity and blood flow
Often, it's not one thing but a combination of training errors, biomechanical issues, and inadequate recovery that leads to breakdown.
When Achilles Tendinitis Becomes Chronic
If caught early, Achilles tendinitis usually responds well to treatment and load management. But if ignored or mismanaged, it can become chronic. Chronic Achilles tendinopathy involves structural changes to the tendon that make it more difficult to treat and more prone to re-injury. In severe cases, the tendon can weaken to the point of rupture, which is a far more serious injury requiring much longer recovery.
When to Seek Help
If you're experiencing pain at the back of your ankle that's affecting your ability to train, walk comfortably, or go about your daily routine, don't wait for it to get worse. Early intervention can prevent progression to more serious tendon issues and help you return to full activity sooner.
Living With Achilles Tendinitis
Achilles tendinitis is manageable with the right approach. Addressing load, improving strength and mobility, and correcting contributing factors can help you recover and reduce the risk of recurrence. At Kevlar Performance & Rehab in Burlington, we work with people dealing with Achilles tendinitis to help them move better and feel better.