Part One of this series on shin pain looked at bony pain, in Part Two of this blog we look at Chronic Exertional Compartment Syndrome (CECS)


There are several muscle “compartments” in the lower leg, each includes muscles, blood vessels and nerves enclosed within soft tissue called fascia. During running the pressure gradually increases in the compartment until you start to experience pain. Symptoms often start at a predictable time during a run then gradually increase, reducing somewhat when you finish. It usually feels tight, tense and sore and can cover most of the shin area depending on what compartment is affected. If the pressure in the compartment is significantly raised it may affect the nerve, causing pins and needles, numbness or muscle weakness.

Adapted from Fraipont and Adamson 2003


Symptoms will depend on what compartment is affected. The anterior compartment is most commonly affected, accounting for around 45% of cases, the deep posterior compartment is second most common at around 40%. Lateral compartment makes up 10% with the superficial posterior compartment around 5%.

The anterior compartment contains 4 muscles (Tibialis Anterior, Extensor Hallucis Longus, Extensor Digitorum Longus and Peroneus Tertius) the tibial artery and the deep peroneal nerve. Symptoms are usually felt within the belly of the Tibialis Anterior muscle. There may be weakness in dorsiflexion (lifting the foot) or toe extension. If the nerve is affected there can be pins and needles or numbness in the top of the foot and the first web space. In severe cases all power to dorsiflexion may be lost and a temporary or persistent “foot drop” can develop.

The lateral compartment contains 2 muscles (Peroneus Longus and Brevis) and the superficial peroneal nerve. Symptoms tend to be felt more along the outside of the shin in the muscles affected. If the nerve is affected there can be pins and needles or numbness in the front and outside of the shin and weakness in ankle eversion (turning the ankle out). I had this during my marathon training. I had a dull ache and pins and needles over the outside of the shin and eversion was weak. My symptoms were there for around 3 weeks then completely resolved with 3 treatments of acupuncture and a change of running shoes.

The deep posterior compartment contains 3 muscles (Flexor Hallucis Longus, Flexor Digitorum Longus and Tibialis Posterior) and the posterior tibial nerve. Symptoms are usually felt around the inside of the shin or back of the lower leg. If the nerves is affected there may be pins and needles or numbness in the sole of the foot and weakness of toe flexion and ankle inversion (turning the foot into).

The superficial posterior compartment contains 2 large muscles (Gastrocnemius and Soleus) and the sural nerve. If the nerve is affected there may be pins and needle or numbness on the top of the foot, on the outside and weakness in plantarflexion (pointing the foot down).

Diagnosis and Investigation

The gold standard for diagnosing compartment syndrome is intracomparmental pressure measurement. This is an invasive procedure and tends to be done after exercise to monitor pressure changes. MRI and Near Infrared Spectroscopy have also been used.

Something to consider with CECS is that if you are symptom free at rest then your doctor or Physio may find very little when examining you. There may be some signs, such as fascial hernias which are quite common in people with CECS but unless you exercise as part of the assessment they may find little else. This can lead to misdiagnosis and it is a condition that is commonly missed.

Causes of compartment syndrome

We know that muscles tend to swell during strenuous exercise and that the compartments in the leg are enclosed within fairly inflexible fascia. So why is it that some people develop a compartment syndrome and some don't?

I think much of it comes down to overloading one particular muscle group while we run. The muscle responds by strengthening and hypertrophy – an increase in muscle size – think Arnie! If the muscle is already enlarged before you start running, the added expansion during a run is too much for the limited space in the compartment. The result is that blood flow into the compartment becomes restricted, the tissues within the compartment become ischaemic (the reduction in blood supply leads to a shortage of oxygen and glucose which is essential for tissue to function). Tissue ischaemic causes pain. When you stop running the pressure in the compartment decreases and normal blood supply can return and symptoms settle.

So why is one muscle group being overloaded? And can you change it?

It's worth remembering at this stage that compartment syndrome comes in varying levels of severity. Also for many, their symptoms may well just be muscle tightness in response to being overloaded and not a fully developed case of compartment syndrome. Up until fairly recently it was thought that compartment syndrome responded poorly to non-surgical treatment and needed surgery but there is growing evidence that it can be treated without going under the knife. One study took 10 runners who were awaiting a fasciotomy surgery and changed their running style to forefoot running. All 10 avoided surgery and returned to running with reduced symptoms. Another smaller study by the same authors similar affects. Forefoot running isn't the only potential solution, a small study showed excellent results for anterior compartment syndrome just with change of footwear. Now, it's worth baring in mind that these are only very small studies and only on patients with anterior compartment syndrome. There are also a number of limitations with study design but at least they suggest that this condition can be changed non-operatively.

Address the causes

In part one of this blog we looked at how certain factors can place greater stress on parts of the bone leading to stress reaction and eventually, if continued, stress fracture. The principles here are similar. Like bony stress I do think it's also a “continuum”, that is it's a gradual increase in stress on tissues and not a sudden switch (like you either have compartment syndrome or don't). Earlier signs may be just tightening and discomfort in the muscle, something many runners experience and probably describe as “shin splints”.

Potential causes are;

  • Training error
  • Poor biomechanics
  • Inappropriate or old footwear
  • Poor running form
  • Excessive running on solid surfaces
  • Poor movement control
  • Muscle weakness
  • Reduced foot and ankle movement
  • Tissue tightness

Symptom management

With compartment syndrome it may be pain free at rest, despite that it can be worth trying these measures to see if they reduce pain when you actually run.

  • Ice – 10 to 15 minutes over the affected area
  • Self massage
  • Compression – many people find wearing compression socks very effective in reducing symptoms when they run
  • Taping – tape can be used to help support the muscles to reduce overloading. It also tends to compress the area. RW have a nice technique here for anterior shin pain.
  • Stretch the affected area
  • Foam roller – be gentle and start in the pain free surrounding areas first
  • Acupuncture – not something you can do on yourself obviously but I found it very effective.

Returning to running

One of the frustrating issues with compartment syndrome is that often symptoms return when running even after a prolonged period of rest. The challenge is to find a way to return to running without symptoms. With my lateral compartment syndrome I noticed some clear patterns. If I started a run too quickly I'd get symptoms, if I gradually built up speed it was far less. If I warmed up well symptoms improved. If symptoms developed when running I could usually reduce them immediately by switching from the road onto grass and slowing just a little. Speed work on concrete was the most aggravating and caused tightness and pins and needles in my leg. I ran Brighton Half Marathon when my symptoms were near their worst. The tightness kicked in around mile 3 and my ankle felt weak. I changed my position on the road regulary so I was running on slightly different cambers. By mile 5 I was symptom free again.

My point here is modify and overcome. See what you can change that allows you to run without your symptoms. It may be speed, distance, running surface, stride length, running shoes, pre-run warm up or training type (hills/ endurance/ interval work etc). In this way you can continue to run and by addressing the causes (as detailed above) your body will adapt to stop overloading one muscle group and then you can gradually return to full training. Bright Half Marathon was February 19th, I ran Brighton Marathon on April 15th completely symptom free.

Like all my posts on here this comes with a message; if in any doubt get checked out. It's always a good idea to have injuries assessed especially if they involve pins and needles, numbness or muscle weakness.



  1. Thanks for this optimistic response to CECS. So many articles dead-end at either facial release surgery or “stop running.” It’s great to hear about your experience continuing running CECS-free.

    • Thanks for the feedback!
      I’m pleased to say I don’t get any issues now when I run. I know other sites that are fairly adamant that surgery is the only answer. I think it’s certainly worth trying physio and modifying your activities. It does depend on severity though.
      Do you have CECS at the moment?

      • Sorry for the delayed reply! I don’t have symptoms now but I did when I ramped up my training this past winter for an HM in March. Enough so that every time I tried to run for a 2-week period, I had excruciating pain, to the point that even stopping and standing was painful. I took several weeks completely off running, and have gradually returned to training. Looking forward to an HM in October injury-free….

  2. Hi,
    Thank you so much for taking the time to write this article. As the previous comment suggests, it is refreshing and encouraging that you aren’t dead set o surgery as the only answer.
    I’ve suspected anterior compartment syndrome for the last three weeks. I went to the physio yesterday and she tends to agree so has prescribed calf stretches, foot exercises and self massage. If you have any other tips, I’d be really interested to hear them.
    Also, could you clarify something for me? If compartment syndrome develops gradually as a continuum, is there a point at which it begins ie. as a result of overtraining or injury? Or rather is it a latent problem that would develop at some point during exercise of that compartment anyway? What I think im trying to ask is whether recovery can get the body back to normal?

    • Hi Tim,
      I think compartment syndrome probably develops gradually as a result of overtraining or biomechanics that place greater stress on a muscle group. Part of the process is hypertrophy of the muscle – extra growth. This can become a problem in a muscle compartment with limited capacity for growth.
      As the muscle is placed under less stress, it may start to atrophy – reduce in size – and if the underlying cause is addressed in theory the body can recover. It depends on severity though and whether the cause can be changed. The fact that there is at least some research indicating a change in running style can help is very encouraging!
      Good luck in your recovery

      • Exactly the question I also had: I can understand muscles getting too big for its compartment. But, if you don’t excercise (run) for say 8 months, why isn’t the muscle decreasing back to its “normal”, before injury, size? At least for me it doesn’t seem to do that…. Tom, you say it “may reduce in size”. Maybe you can elaborate some more on this? Why is it “may” and not “will”?

  3. Thanks for writing this up and your previous blogs, they are very informative. I do like how you mentioned that forefoot running can be used to treat CECS in the anterior compartment. This is understandable due to the forces being transferred to the posterior compartment when transitioning to this foot strike while running.

    My question for you is then, I feel that by the same reasoning, if you have a patient who presents with posterior compartment syndrome it would seem logical to educate them on changing to a heel strike pattern (knowing that you are going to then have the force spike) to decrease the forces in the posterior compartment. Thoughts?

    Thanks for your time,
    Russell McCluskey, SPT

  4. Hello again,
    Today I ran more than a mile for the first time in 5 week. Taking on board your comments about modifying and overcoming the symptoms I focused on running in a forefoot style, having read a few articles and watched various videos about the technique. The first run into town was just over 3 miles. While I could feel the symptoms of conpartment syndrome waiting to pounce, the pain only reached a 3 or 4 out of 10 level, which was fine. I stretched on arrival and then walked around the shops, leading the symptoms to entirely disappear. Buoyed by this success, I thought I would attempt a gentle run home, using the same style and pace just a goong a bit further (6 miles). Again, symptoms appeared but only reached a 3 out of 10 level and in fact were barely present by the end of the run. However, the forefoot style did cause my groin and front of my thighs to ache more than I was used to, but nothing untoward. All in all, I ran just over 9 miles in two stages and feel pretty good, although tomorrow will tell me more.
    My question is, do you think it possible to run a marathon on 5th May? If so, how should I approach training? Before I ceased training due to the onset of compartment syndrome, I had comfortably run a couple of 20 mile
    LSRs, and since then I have maintained my cardio fitness pretty well through cycling. I have read you article on Returning From Injury, but I feel that Conpartment Syndrome requires a slightly different approach and would be enormously grateful of any help. Thanks in advance.

  5. This is the most encouraging information I’ve found! Thank you.
    My CECS came on following a hard 6 miles Nov. 2, ’13. I rested the leg, took ibuprofen, and iced it several times a day for a week with no relief. Went to a sports medicine Dr. and was prescribed PT, which has included stretches, some massage. Initially I could not walk 100 yards, now I can walk 3+ miles, but pain is still at an uncomfortable level. Most of what I’ve read concerning treatment is RICE. My question has to do with the Rest. If walking brings on the pain/pressure, should I discontinue walking for a period of time? The pain level does seem to be decreasing ever so slightly on the daily walks. My concern is that daily walks are further aggravating the problem.

  6. With tibialis post is cushioned heal striking modification the way to go. treating it like the Achille s and calf and to offload it. Compared to tib ant where ffs is obviously the theoretically preferred style?

  7. Thankyou so much! I went to so many doctors with so many injuries and have spent countless hours crying over the 24/7 pain, I took 13 long weeks off of running and no matter how hard it was not doing what I love I did it because I needed the recovery! I recently started running by running a mile at 10 min mile pace and I’m in south pain right now, I will do the treatments and hopefully this pain will away for good! Thanks again

Comments are closed.