What is the paratenon?
Your Achilles tendon, the thick band running from your calf muscles down to your heel bone, sits inside a thin layer of connective tissue called the paratenon. Picture a loose sleeve around the tendon. It lets the tendon glide as your ankle moves and it carries some of the blood supply that keeps the tendon healthy. When that sleeve swells and inflames you have paratenonitis, which older textbooks call peritendinitis.
This is not the same thing as Achilles tendinopathy, where the change happens inside the tendon itself: thickening, disorganised collagen, degeneration. Paratenonitis is inflammation of the tissue wrapped around the tendon, and the tendon underneath may be completely normal. The two can run together though, and paratenonitis left alone long enough will start to pull the tendon into it.
How does it happen in rugby?
The paratenon gets into trouble when friction between it and the tendon goes past what the tissue can put up with. A few things do that reliably in rugby:
- Pre-season is the classic one, because you go from an off season of almost no running to a full week of it with nothing in between
- Surfaces change under you, from soft grass to hard artificial turf or from flat ground onto hills, and the calf and Achilles take more load for the same session
- Worn boots, or boots with poor heel support and studs that change how your ankle sits, push more friction through the paratenon
- Hill sprints and repeated accelerations work the calf and Achilles hardest, so a block of them is a common trigger
- You train more often without leaving room to recover, doubling up sessions or running on back-to-back days, and the tissue never gets the gap it needs to adapt
1-2 weeks
Typical onset
after a sudden training change
2-4 weeks
Conservative resolution
with early treatment
3-6 months
Chronic cases if untreated
adhesions complicate recovery
What does it feel and look like?
It shows up differently from mid-portion Achilles tendinopathy, and the two are worth telling apart before you decide what you are dealing with:
| Feature | Paratenonitis | Mid-portion tendinopathy |
|---|---|---|
| Swelling location | Spread around the tendon, so the whole area looks puffy rather than showing one lump | Focal and inside the tendon, a thickening or nodule you can find 2 to 6 cm above the heel |
| Crepitus | Often there, a crackling or creaking you feel under your fingers and sometimes hear as the ankle moves | Usually absent, because the tendon itself does not crackle |
| Pain pattern | Worst as you start, eases once you are warm, then comes back after you stop, and mornings are stiff | Hurts during and after loading, particularly when the tendon gets compressed by jumping or hill running |
| Tenderness on examination | The sore spot travels with the tendon as you point and flex your foot, because the paratenon moves with it | One fixed sore spot that stays put whatever the ankle is doing, because the problem sits inside the tendon at that point |
| Warmth and redness | Can be there, since this one is genuinely inflammatory and an acute case sometimes looks and feels hot | Usually not, since tendinopathy is a degenerative process rather than an inflammatory one |
Why does it matter for rugby players?
Paratenonitis sits at a fork in the road. Handled early it is a minor overuse problem that settles in a couple of weeks on load management alone, but left to grind on it turns into adhesions, grumbling inflammation and eventually damage to the tendon underneath, which is the version that costs a player months. What decides which way it goes is mostly how fast you notice and how fast you take the load off.
If you keep gliding an inflamed paratenon over the tendon under load, the body answers by laying down adhesions, bands of fibrous scar that stick the sleeve to the tendon. Those bands stop the tendon moving freely, interfere with its blood supply and concentrate stress at a few points along it, and that is how a tendon that started out healthy ends up with tendinopathy. Catch the paratenonitis early and none of that gets going.
How to settle it down
Treatment here is mostly load management and a few habits, and it is a much shorter job started in the first week than in the fourth:
- Back the running off to a level that does not provoke symptoms. That is not the same as stopping, so keep cycling, swimming or light gym work going while the paratenon calms down.
- Ice after activity, 15 to 20 minutes, two or three times a day while it is acute. It brings the swelling down and takes the edge off the pain.
- Gentle stretching keeps the tendon and its sleeve gliding on each other, so hold 30 seconds on the gastrocnemius with your knee straight and 30 on the soleus with your knee bent, three or four times a day.
- Hills, sprinting and hard accelerations come out until the symptoms have gone, and flat jogging or pool running goes in so you keep your fitness.
- Have a look at your boots for heel support and cushioning, and a temporary heel lift of 5 to 10 mm will take some tension off the Achilles while it heals.
- Short-term anti-inflammatories, five to seven days of them, are one of the few times NSAIDs are clearly the right call for an Achilles, because here inflammation genuinely is the problem rather than the side note it is in tendinopathy. Check with your pharmacist or doctor before you start on them.
Return to running
Settle it down
Days 1–7
Take the running down to nothing, or to a jog that does not hurt at all, and ice it after everything you do. Stretch the calf twice a day, gastrocnemius and soleus both. Cycling, swimming or upper body work in the gym keeps your fitness while the ankle is quiet. You leave this phase when the crepitus and the tenderness have gone, not when the calendar says so.
Start jogging again
Days 8–14
Jog on flat ground at a pace where you could still hold a conversation, 10 to 15 minutes at first, adding 5 minutes every second day, and stretch the calf before and after each run. Keep hills and sprinting out of it for now. Check for crepitus before you set off, and if it has come back, drop to Phase 1 again.
Build the running back up
Weeks 3–4
Bring the jogging back up to what you were doing before, then add tempo runs and moderate intervals, and put gentle hill work back in at jogging pace rather than as sprints. Rugby running comes back here too, changing direction, accelerating and pulling up, at 70 to 80% effort. Keep checking for crepitus after each session.
Back in full
Week 4+
Everything goes back in, sprinting, hill work and contact. You know the paratenon has healed when a full session and a full match day pass without crepitus, and you wake up the next morning with no tenderness and no stiffness. Keep the calf stretching and a proper warm-up going after that, because they are the cheapest prevention you have.
When conservative management fails
Where paratenonitis has been ignored for weeks or months before anyone treated it, the adhesions can settle in and stop answering to rest and stretching. That is the point at which a surgeon may offer a release, opening the paratenon and freeing the scar tissue between the sleeve and the tendon so the two glide again. Coming back from that runs somewhere in the region of eight to twelve weeks. It is a long way round for something that answers to two to four weeks of sensible loading, which is the argument for taking the early signs seriously.
Keeping it from coming back
- Build running volume in steps rather than jumps, and the 10% rule is the usual guide: no more than a 10% increase in weekly distance from one week to the next
- When you move from grass to artificial turf or back the other way, cut your running volume by 20 to 30% for the first week on the new surface
- Calf flexibility is worth staying on top of, so stretch the gastrocnemius and the soleus regularly, especially after training
- Boots and trainers lose their cushioning long before they look worn out, so replace running shoes every 500 to 800 km and your boots every season
- Nothing loads the Achilles as abruptly as going from an off season of rest straight into pre-season, so start a structured return-to-running programme two or three weeks before formal pre-season and the tissue gets a ramp instead of a step
- Morning stiffness around the Achilles that hangs about for more than 10 minutes, or soreness down both sides of the tendon after a run, are the early signs, and sorting them then is what stops crepitus turning up at all