Achilles pain is one of the most common running injuries, but not all Achilles pain is the same. Whether the pain is in the middle of the tendon or right where it attaches to the heel changes how we manage it, and some of the most common advice can make one type worse.
If you're a runner, there's a fair chance you've felt it: stiffness at the back of the ankle when you get out of bed, a few painful steps on the way to the bathroom, then a tendon that warms up and feels fine once you're a kilometre into your run, only to bite back that evening or the next morning.
Achilles tendinopathy is one of the most common overuse injuries in runners. But there are two quite different types, and they behave differently and need different approaches. In this post I'll explain the difference between mid-portion and insertional Achilles tendinopathy, how to tell which one you might have, why it matters for your rehab, and how to keep running while you get on top of it.
What is Achilles tendinopathy?
The
Achilles tendon is the thick tendon at the back of your ankle that connects your calf muscles, the gastrocnemius and soleus, to your heel bone. It's the strongest tendon in the body and handles forces of several times your body weight with every running stride.
Achilles tendinopathy happens when the tendon is loaded more than it's currently able to handle, and its structure changes as it tries to adapt. You may have heard it called Achilles tendinitis. That name suggests the main problem is inflammation, but research shows that in most cases it isn't. The tendon has been overloaded, it becomes painful and less able to tolerate load, and it needs progressive loading, not just rest, to recover. I've explained this in more detail in
A Physio's Lowdown on Tendinopathies.
In runners, Achilles tendinopathy is usually triggered by a change in load, such as:
- A jump in weekly distance or the number of runs
- Adding hills, speed sessions or track work
- A change in footwear, especially moving to a lower heel drop or minimal shoes
- Returning to running after a break
- Training for an event, like a half marathon or marathon
Other factors include calf weakness, age, as tendons become a little less resilient from our late thirties onwards, and some medical conditions and medications, which your GP can help with.
Mid-portion vs insertional: what's the difference?
The key difference is where the pain is.
Mid-portion Achilles tendinopathy
This is the most common type, especially in runners. The pain is in the body of the tendon, typically around 2 to 6 centimetres above where it attaches to the heel. Common features include:
- Pain and stiffness in the middle of the tendon
- Morning stiffness that eases as you warm up
- A tendon that may feel thickened or have a tender lump when you pinch it gently
- Pain that warms up during running and is worse later or the next day
Insertional Achilles tendinopathy
This type affects the point where the tendon attaches to the back of the heel bone. Common features include:
- Pain right at the back of the heel, where the tendon meets the bone
- Pain with uphill running, stairs and anything that pulls the toes up towards the shin
- Pain with pressure from the back of shoes
- Sometimes a bony prominence at the back of the heel, known as a Haglund's deformity
- Often stiffer and slower to settle than mid-portion tendinopathy
Insertional tendinopathy is a bit more common in older runners and people who are less active, but plenty of runners get it too. Some people have both types at once.
Why the difference matters
At the heel attachment, the tendon wraps around the back of the heel bone. When you pull your toes up towards your shin, called dorsiflexion, the tendon is pressed against the bone. This compression is thought to be one of the main things that irritates insertional tendinopathy.
That's why some of the classic advice for Achilles pain can make insertional tendinopathy worse:
- Calf stretches that drop the heel down, especially off a step, compress the insertion.
- Heel drops off the edge of a step, which are a staple for mid-portion tendinopathy, take the ankle into a lot of dorsiflexion and often aggravate insertional pain.
- Uphill running and stairs load the insertion in a compressed position.
For mid-portion tendinopathy, compression isn't a major issue, so exercises through full range, including heel drops off a step, are usually fine and are a well-researched part of rehab. This is the main reason it's worth getting the type of Achilles tendinopathy right before diving into a program you found online.
How do I know which one I have?
A physio can usually tell from your history and a clinical assessment. I'll ask where exactly your pain is, how it behaves, and what aggravates it, then examine the tendon, check your calf strength and endurance, and test how the tendon responds to loading, like single-leg calf raises and hopping.
Scans aren't usually needed. An ultrasound or MRI can show changes in the tendon, but similar changes are often seen in people with no pain, so they don't reliably tell us how you'll recover. Imaging is more useful if a tear is suspected, if the diagnosis is unclear, or if you're not improving as expected.
It's also important to rule out other causes of heel and ankle pain, including bursitis at the back of the heel, a
stress fracture of the heel bone, nerve irritation and, in younger runners,
Sever's disease. Pain on the bottom of the heel is more likely to be plantar heel pain, which I've written about in my post on
plantar fasciitis.
Rehab for mid-portion Achilles tendinopathy
The foundation of rehab for mid-portion tendinopathy is progressive calf strengthening. A typical progression looks like this:
- Isometric holds: holding a calf raise position, or pushing against a wall, for 30 to 45 seconds. Useful early on when the tendon is irritable, as they often ease pain.
- Double-leg calf raises: progressing to single-leg calf raises, done slowly, about three seconds up and three seconds down.
- Full-range calf raises off a step: lowering the heel below the level of the step, which is well tolerated in mid-portion tendinopathy.
- Bent-knee calf raises: to target the soleus, which takes a large share of the load during running.
- Heavy, slow loading: adding weight with a backpack, dumbbells or a calf raise machine, building up over weeks.
- Plyometrics: skipping, hopping and bounding to prepare the tendon for the spring-like demands of running.
Two well-known approaches, a daily eccentric program and a heavy slow resistance program done three times a week, both have good research support. I usually lean towards heavy, slow strength work a few times a week, because it's effective and easier to stick with, and adapt it to each runner.
Rehab for insertional Achilles tendinopathy
The principles are the same, progressive loading to build the tendon's capacity, but we protect the insertion from compression, especially early on:
- Calf raises on flat ground, not off a step, so the heel doesn't drop below level. As symptoms settle, we gradually introduce more range.
- Isometric holds in a mid-range position to ease pain.
- Heavy, slow strength work in a range that doesn't aggravate the heel.
- A small heel raise in your shoes for a while, which reduces dorsiflexion and compression at the insertion.
- Avoiding calf stretches that drop the heel down while it's irritable.
- Footwear changes: shoes with a slightly higher heel drop, and heel counters that don't press on the sore spot.
Insertional tendinopathy often takes longer to settle than mid-portion. It's common to need three to six months of consistent work, so patience and consistency are important.
Can I keep running?
Usually, yes. Complete rest isn't usually necessary and can leave the tendon less able to cope when you return. Instead, I use a pain monitoring approach:
- Pain during running of up to around 3 out of 10 is generally acceptable
- Pain should settle within a few hours of finishing
- Morning stiffness the next day shouldn't be worse than usual
Morning stiffness is a really useful guide, because the tendon tells you the next day how it coped with yesterday's load. If it's worse, ease off. If it's stable or better, you're on track.
To keep running while your tendon settles, the first things I usually adjust are:
- Speed and hills: reduce speed work, hill repeats and track sessions, which load the Achilles the most. For insertional tendinopathy, cutting back uphill running is particularly important.
- Volume: reduce weekly distance, and avoid back-to-back running days for a while if needed.
- Surface: flat, even surfaces are usually easier than trails and hills.
- Footwear: avoid sudden changes, and consider a shoe with a bit more heel drop for insertional pain.
- Cadence: a small increase in step rate can reduce the load on the calf and Achilles for some runners. I've written more about this in my post on optimising your running technique.
If running is too painful, cycling, swimming and other low-load cardio can maintain your fitness while we build the tendon back up. Then we return to running with a gradual program, often starting with run-walk intervals.
A sample week during rehab
Every runner's plan is different, but here's what a typical week might look like for someone with mid-portion Achilles tendinopathy who is still running at a reduced level:
- Monday: calf strength session, including heavy, slow single-leg calf raises and bent-knee calf raises
- Tuesday: easy run on flat ground
- Wednesday: rest or cross-training, like cycling or swimming
- Thursday: calf strength session, plus some light hopping or skipping if the tendon is ready
- Friday: rest
- Saturday: easy run, slightly longer than Tuesday
- Sunday: calf strength session or rest
Running and strength sessions are spread out so the tendon has recovery time between harder days. For insertional tendinopathy, the plan looks similar, but the strength exercises are done on flat ground and hills are left out until the heel settles.
Other treatments
Alongside exercise, some treatments can help ease symptoms in the short term, including
soft tissue work for the calf,
taping, and shockwave therapy, which has some evidence for both types of Achilles tendinopathy and is available through some clinics. Corticosteroid injections are generally avoided near the Achilles because of concerns about tendon weakening. These treatments can help, but the long-term changes come from strengthening the tendon.
When to see a physio or doctor
It's worth getting your Achilles assessed if pain has been around for more than a couple of weeks, if it's getting worse despite cutting back, or if it's stopping you from running. See a doctor urgently if you felt a sudden pop or a sensation like being kicked in the back of the ankle, followed by weakness pushing off. That can indicate an Achilles rupture, which needs prompt medical care.
How I help runners with Achilles pain
When I see a runner with Achilles pain, I start by working out which type of tendinopathy it is and what changed in your training before it started. I'll test your calf strength and endurance, look at how your tendon handles hopping and running, and talk through your running goals and upcoming events.
From there, we build a plan that combines a staged
strength program, a running plan with clear rules for progressing and pulling back, and adjustments to footwear and training. Because I'm a mobile physio, I can see you at home or meet you at the track or local park to look at your running. You can read more about how I manage tendon problems on my
tendinopathy physiotherapy page, and more about tendon loading in my post on
exercise for tendinopathy.
The bottom line
Mid-portion and insertional Achilles tendinopathy are both common in runners, and both respond to progressive loading. The key difference is that insertional tendinopathy doesn't like compression, so heel drops off a step, calf stretches and hills often need to be avoided early on. Getting the right diagnosis, building calf strength consistently and managing your running load are the keys to getting back to running comfortably. If Achilles pain is holding back your running, I'd be happy to help you work out a plan.
This article is general information only and isn't a substitute for an individual assessment. If you have pain or an injury, speak with your physiotherapist or GP about your situation.
