Chronic Exertional Compartment Syndrome

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Expert Patient Guide · London

Chronic Exertional Compartment Syndrome of the Leg

A guide for patients, written by Mr Matthew Welck, Consultant Orthopaedic Foot & Ankle Surgeon at the Royal National Orthopaedic Hospital (RNOH) Stanmore and UCL — London, UK.

At a Glance: Chronic Exertional Compartment Syndrome

ConditionChronic exertional compartment syndrome (CECS) — pressure builds up inside one or more of the muscle compartments in your lower leg when you exercise.
Who It AffectsUsually active people under 25 — runners, footballers, hockey and racket-sport players, dancers and military recruits.
Estimated FrequencyAbout 1 in 2,000 active people each year. It is one of the main causes of leg pain brought on by exercise.
Main SymptomAching, cramping or a feeling of tightness or fullness in the leg. It builds up the longer you exercise and settles within minutes of stopping.
Compartments InvolvedAnterior, at the front (the most common, about 40%), lateral at the side, and the superficial and deep posterior compartments at the back. About 60% of patients have more than one compartment affected.
DiagnosisYour symptoms and an examination, plus a pressure test inside the muscle compartment before and after exercise (the Pedowitz criteria). An MRI scan helps rule out other causes.
Non-Surgical CareChanging your activity, running-gait retraining, physiotherapy, insoles (orthotics) and botulinum toxin injections.
Surgical OptionFasciotomy — an operation to release the tight fascia. About 60–100% of athletes get a good or excellent result.
SpecialistMr Matthew Welck — Consultant Foot & Ankle Surgeon, RNOH Stanmore & UCL, London. matthewwelck.com

01

What Is Chronic Exertional Compartment Syndrome?

Chronic exertional compartment syndrome (CECS) is pain and tightness in the leg that comes on with exercise. It happens because pressure rises again and again inside one or more of the muscle “compartments” in your lower leg. Each compartment — the front (anterior), the outer side (lateral), and the superficial and deep compartments at the back (posterior) — is wrapped in a tough sheet of tissue called fascia, which does not stretch much.

When you exercise, the working muscle can swell by up to 20%. Normally the fascia has enough give to allow this. In CECS it does not, so the pressure rises, the blood flow falls and the nerves and muscle are squeezed. This causes the typical pain, which only eases when you stop.

Not the same as an emergency: This is very different from acute compartment syndrome, which happens after an injury and needs surgery straight away. CECS is long-standing, comes on with exercise, and settles with rest. Seeing a Consultant Foot & Ankle Surgeon who specialises in sports injuries — such as Mr Matthew Welck in London — can confirm the diagnosis and rule out the many other conditions that can look similar.

02

How Common Is It?

CECS mainly affects young, active people. The best estimate — mostly from studies in the military — is that it affects about 1 in 2,000 active people each year. It is one of the most common causes of exercise-related leg pain in runners, footballers, hockey and racket-sport players, dancers and military recruits.

You are more likely to get CECS if you are under 25, if you run or skate, if you have symptoms in both legs, and if the compartment feels tight and tender when it is examined. Men and women are affected about equally. Less often, it can happen in older or less sporty people too.

03

What Causes CECS?

We do not fully understand what causes CECS, and it is almost certainly a mix of things:

  • Fascia that does not stretch — the lining around the compartment cannot give as the muscle swells during exercise, so the pressure rises
  • Bigger muscles — well-trained muscles grow and fill the fixed space inside the compartment
  • Less blood flow — the high pressure reduces the blood supply (ischaemia) and squeezes the nerves inside the compartment
  • Repeated small injury — to the muscle from heavy training loads
  • Running style — landing heavily on the heel, and the foot rolling inwards (overpronation), put more load on the compartment
  • Nerve involvement — more than a third of patients have a small gap in the fascia where the superficial peroneal nerve comes through

04

What Are the Symptoms?

The key sign of CECS is that symptoms come on with exercise and settle with rest:

  • Aching, cramping or a feeling of “fullness” deep in the leg that builds up the longer you exercise
  • Quick relief with rest — the pain usually settles within minutes of stopping, and occasionally takes up to an hour
  • Both legs affected in a large number of patients
  • Tingling or numbness over the top of the foot (from the superficial peroneal nerve)
  • Weakness or “foot drop” — tripping, or the foot slapping down, for a short time during a flare-up
  • Where it hurts depends on the compartment — the front or outer side of the shin (anterior and lateral), or the inner calf (deep posterior)
  • A leg that seems normal at rest — an examination between episodes is often normal, which is itself an important clue

05

What Investigations Might You Need?

Because the leg often looks and feels normal at rest, a careful, structured assessment is essential:

  • History and examination — ideally done before and after exercise or a run on a treadmill
  • Dynamic intracompartmental pressure (ICP) testing — measuring the pressure inside the compartment, which is the current gold standard, using the Pedowitz criteria (15 mmHg or more at rest, 30 mmHg or more one minute after exercise, or 20 mmHg or more five minutes after)
  • MRI scan — to pick up exercise-related changes in the muscle and, importantly, to rule out a stress fracture and other causes
  • Near-infrared spectroscopy (NIRS) and shear-wave elastography — newer tests that do not need a needle, now starting to be used in specialist practice
  • Tests to rule out other conditions — X-ray or bone scan (stress fracture), duplex ultrasound scan or MR angiography (a trapped artery behind the knee), nerve conduction studies (a trapped nerve) and the ankle–brachial index (poor circulation)

CECS shares features with medial tibial stress syndrome (shin splints), stress fractures, a trapped artery behind the knee and trapped nerves. Getting the right diagnosis — and seeing an experienced specialist to make it — really does matter.

06

Non-Surgical Treatment Options

Many patients get better without an operation. Non-surgical treatment is usually tried first for three to six months:

  • Activity modification — changing your activity, and a period of relative rest to settle the symptoms
  • Running-gait retraining — landing on your forefoot rather than your heel, taking more steps per minute (towards about 180) and keeping an upright posture all lower the load on the compartment. With a structured programme, about half of patients avoid surgery
  • Physiotherapy — stretching, massage, soft-tissue work and strengthening
  • Footwear and insoles (orthotics) — correcting the foot rolling inwards and choosing the best running shoes
  • Anti-inflammatory medicine to ease symptoms
  • Botulinum toxin (Botox) injections — a newer option. In early studies the pain settled in most patients, with a large fall in the pressure inside the compartment
  • Diagnostic lidocaine injections — a local anaesthetic injection, used more and more to confirm the diagnosis and work out which compartments are involved

07

Surgical Treatment (Fasciotomy)

If symptoms carry on despite a proper trial of non-surgical treatment, an operation to release the tight fascia — a fasciotomy — is the definitive treatment. The idea is simple: open the fascia around the affected compartment or compartments so the muscle has room to expand when you exercise. The approach is chosen to suit you.

Open Fasciotomy

One or two small cuts are used to release the compartment while the surgeon can see it directly, carefully protecting the superficial peroneal nerve. Careful handling of this nerve is vital — damage to it is a frequently reported reason for CECS surgery failing.

Minimally Invasive / Endoscopic-Assisted Release

Smaller cuts with the help of a camera, in selected cases. The results are broadly similar to open release, and the choice depends on which compartments are involved and on the surgeon’s experience.

Fasciectomy

Removing a strip of fascia rather than simply splitting it — usually kept for symptoms that come back after a previous fasciotomy.

Recovery and Outcomes

You will be able to put weight on the leg early, in a boot, so the fascia does not heal back down. Stitches come out at 10–14 days, and you build up gradually through cycling and strength work to running by about three to four months. About 60–100% of athletes get a good or excellent result, and the anterior and lateral compartments tend to do better than the deep posterior compartment. As with any operation there are risks — about 19% of patients have a complication, including bleeding, nerve irritation, problems with wound healing and symptoms coming back — and all of these are discussed fully with you before any decision to operate.

08

Why Choose Mr Welck?

Mr Matthew Welck is a Consultant Orthopaedic Foot & Ankle Surgeon at the Royal National Orthopaedic Hospital (RNOH) Stanmore — one of the UK’s leading specialist orthopaedic centres — and Honorary Associate Clinical Professor at UCL.

He treats only foot and ankle problems, with a special interest in sports injuries of the foot, ankle and lower leg, where getting the diagnosis of exercise-related leg pain right is essential. He has written more than 50 peer-reviewed papers, has completed two specialist fellowships including training abroad, and is a pioneer of Weight-Bearing CT and 3D-printed instruments made for each patient.

Patients are seen across North and Central London, with quick access to MRI scans, dynamic pressure testing and a sports rehabilitation team. His full foot and ankle service also includes conditions such as ankle arthritis and total ankle replacement. Every option is talked through openly, and a plan is agreed together that is tailored to you.

09

Frequently Asked Questions

What is chronic exertional compartment syndrome?

CECS is pain and tightness in the leg brought on by exercise. It is caused by pressure rising again and again inside one of the muscle compartments of the lower leg. The tissue wrapped around the muscle cannot stretch enough during exercise, so the pressure builds, the blood flow drops and the leg aches until you stop.

Is CECS the same as shin splints?

No. Shin splints (medial tibial stress syndrome) cause tenderness along the inner edge of the shin bone and are a different problem, although you can have both together. A careful assessment tells them apart — and rules out stress fractures and trapped arteries or nerves.

How is CECS diagnosed?

The diagnosis is based on a typical history and, where needed, a pressure test inside the compartment before and after exercise using the Pedowitz criteria. MRI and other tests are mainly used to rule out conditions that look similar.

Can CECS be treated without surgery?

Often, yes. A three-to-six-month programme of activity changes, running-gait retraining, physiotherapy and insoles helps many patients, and about half avoid surgery with structured gait retraining. Botulinum toxin injections are a promising newer option.

What does CECS surgery involve?

The operation is a fasciotomy — the tight fascia around the affected compartment is released through one or two small cuts, so the muscle can expand freely when you exercise. The superficial peroneal nerve is carefully protected throughout.

How long is the recovery after fasciotomy?

Most people put weight on the leg early in a boot, have their stitches out at 10–14 days, and build up through cycling and strengthening back to running by about three to four months.

Will I be able to run and play sport again?

The aim of surgery is to get you back to sport. About 60–100% of athletes get a good or excellent result, and the anterior and lateral compartments respond best. Your likely outcome is discussed honestly and individually before any decision.

Is CECS dangerous?

The chronic, exercise-related form is not an emergency and settles with rest — quite unlike acute compartment syndrome after an injury, which is a surgical emergency. CECS mainly affects your quality of life and your ability to exercise.

Where can I see a foot and ankle surgeon for CECS or sports leg pain in London?

Mr Welck consults across North and Central London. NHS patients are seen at the Royal National Orthopaedic Hospital (RNOH) Stanmore. Private appointments can be booked on 07547 395 270 or by emailing secretary@matthewwelck.com.

10

Book a Consultation

If leg pain brought on by exercise is limiting your running, sport or training, seeing a specialist can make a real difference — both in getting the right diagnosis and in choosing the treatment most likely to get you back to full activity.

Book a private or NHS appointment with Mr Matthew Welck, Consultant Foot & Ankle Surgeon. Seeing an expert early gives you the widest choice of options and the best long-term result.

This page is for information only. It does not replace personalised medical advice. Always consult a qualified specialist for diagnosis and treatment.

Written by: Matthew Welck | Consultant Orthopaedic Foot & Ankle Surgeon London — last updated 16 August 2026

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