Who tends to develop compartment syndrome?

The acute form mainly affects young, active people, especially athletes and military personnel, with tibial fracture a common cause. The chronic exertional form is more often seen in long-distance runners, military personnel, and athletes who repeatedly use the calf muscles. Studies report that among competitive athletes the incidence of exercise-related pain can reach 27-33%.

Why does compartment syndrome happen?

In the acute form, pressure within the compartment rises above capillary perfusion pressure, causing ischemia of muscle and nerve. The chronic exertional form is related to muscle swelling from repeated exercise and increased interstitial pressure within the fascial compartment, and may be associated with fascial stiffness, abnormal blood perfusion, and local metabolic factors.

What factors increase the risk?

The acute form is commonly associated with lower-leg fractures (tibial fracture most common), direct impact or blunt-force injury, prolonged compression, and bleeding. The chronic exertional form is related to repetitive exercise, overdeveloped muscle, overly tight fascia, and gait or biomechanical abnormalities.

How do the symptoms of acute and chronic compartment syndrome differ?

The acute form produces persistent, severe pain out of proportion to the injury, worsened by passive stretching of the muscle group and not relieved by elevating the limb. Pain in the chronic exertional form is exercise-related, usually appearing 10-30 minutes after starting activity, often bilateral, and easing gradually 15-30 minutes after stopping.

What might a physical examination find?

In the acute form, the limb may be swollen and tense, passive stretching of the anterior calf muscles causes severe pain, ankle dorsiflexion strength may be reduced, and pulses are usually normal. In the chronic exertional form, examination at rest is often unremarkable, and assessment immediately after exercise may be needed before swelling, tenderness, and reduced strength appear.

Unexplained Lower-Leg Pain? Understanding Acute vs. Chronic Compartment Syndrome

Compartment syndrome is an abnormal rise in pressure within the muscle compartments of the lower leg that restricts blood flow and causes tissue ischemia. It can be divided into an acute form and a chronic form (also known as chronic exertional compartment syndrome, CECS).

Acute compartment syndrome is a medical emergency, often caused by trauma (such as a fracture or contusion) or bleeding, and needs urgent treatment to prevent tissue necrosis.
Chronic exertional compartment syndrome (CECS) is usually caused by repetitive exercise, with symptoms that appear during activity and ease after rest.

Epidemiology

Acute compartment syndrome
Mainly affects young, active people, especially athletes and military personnel.
In orthopedic trauma, tibial fracture is one of the common causes of ACS, and the highest incidence usually falls in young to middle-aged adults (roughly 20-40 years).
Chronic exertional compartment syndrome (CECS)
Most often occurs in long-distance runners, military personnel, and athletes who repeatedly use the calf muscles (such as in soccer, basketball, and skiing).
It can affect both men and women, and studies show little difference between them.
It can occur in the forearm, thigh, and foot, but most cases are in the lower leg; CECS may also occur in other leg compartments (for example, the lateral compartment and the deep posterior compartment), not only the anterior compartment.
Upper limb: rowing, tennis, motorcyclists, and others; lower limb: runners, dancers, gymnasts, and military personnel.
The leg is also the most common site of compartment syndrome in children; vascular causes are the most common etiology (28%), followed by trauma (26%), postoperative (21%), overexertion (15%), and infection (10%). Because the bone is still growing, the fascial enclosure is relatively tight, and pain is expressed less clearly, so a higher index of clinical suspicion is needed.

Etiology

Acute compartment syndrome (ACS)
Pressure within the leg compartment rises above capillary perfusion pressure, causing ischemia of muscle and nerve.
If not treated promptly, it can lead to muscle necrosis, nerve injury, and even permanent disability.
Chronic exertional compartment syndrome (CECS)
Mainly related to muscle swelling from repeated exercise and increased interstitial pressure within the closed fascial compartment, which can produce ischemic pain that may be associated with sensory abnormalities and muscle dysfunction.
Among competitive athletes, the incidence of exercise-related pain is as high as 27-33%.
Pressure can return to normal with rest, but continued exercise triggers symptoms again.
It may be associated with fascial stiffness, abnormal blood perfusion, and local metabolic factors.
Because of the vague nature of the symptoms, CECS is easily misdiagnosed. Delayed diagnosis can increase the severity of the condition.

Risk factors

Acute compartment syndrome (ACS)
Lower-leg fracture (tibial fracture most common)
Direct impact or blunt-force injury (such as a car accident, fall, or sports injury)
Prolonged compression (such as in comatose patients or when the leg is pinned under a heavy object)
Hematoma or bleeding after anticoagulant use
Burns causing swelling and raised intracompartmental pressure
Chronic exertional compartment syndrome (CECS)
Repetitive exercise (such as running, soccer, basketball, military training)
Overdeveloped muscle (which may raise intracompartmental pressure)
Overly tight or insufficiently supple fascia
Gait abnormalities or biomechanical abnormalities

History

Acute compartment syndrome (ACS)
- Main symptom: severe, persistent pain out of proportion to the injury.
- Severe pain on passive stretching of the anterior muscle group.
- Pain usually worsens within a few hours of injury and is not relieved even at rest or with elevation of the limb.
- It may be accompanied by sensory abnormalities (such as numbness or tingling), typically affecting the area supplied by the superficial peroneal nerve (dorsum of the foot).
Chronic exertional compartment syndrome (CECS)
Pain is exercise-related, usually appearing within 10-30 minutes of starting activity.
Pain is usually bilateral.
Symptoms include a sense of pressure, swelling, weakness, or numbness in the anterior calf.
After stopping exercise, symptoms usually ease gradually within 15-30 minutes.
Continuing to exercise may cause foot weakness that affects gait (such as foot drop).

Physical examination

Acute compartment syndrome (ACS)
The limb is swollen, tense, and markedly tender.
Passive stretching of the anterior calf muscles (such as pressing the toes downward) causes severe pain (an important sign).
Strength may be reduced, especially ankle dorsiflexion (because the tibialis anterior is affected).
Sensory abnormalities or numbness, most often on the dorsum of the foot (the superficial peroneal nerve territory).
Pulses are usually normal (because restricted arterial flow appears only in later stages).
Chronic exertional compartment syndrome (CECS)
Examination is usually unremarkable, but after exercise the following may be seen:
- Swelling and tightness in the anterior calf
- Local tenderness (especially over the tibialis anterior)
- Reduced ankle dorsiflexion strength
- Sensory abnormalities in the foot (such as numbness or tingling)
Symptoms improve after rest, so assessment immediately after exercise may be needed.

Differential diagnosis

Acute compartment syndrome (ACS) should be distinguished from the following:
Tibial fracture: although a fracture may be accompanied by compartment syndrome, a simple fracture should not cause persistent, worsening pain.
Deep vein thrombosis (DVT): causes swelling and pain, but not pain on passive stretch or muscle tenderness.
Arterial occlusion (acute limb ischemia): causes pallor and absent pulses, but usually without the tense feel of compartment syndrome.
Nerve compression or neuritis: usually without muscle swelling or tenderness.
Chronic exertional compartment syndrome (CECS) should be distinguished from the following:
Tibialis posterior overuse or periostitis (shin splints): usually diffuse pain, with less relationship to exercise duration.
Stress fracture: marked local bone tenderness, with bone damage visible on X-ray or MRI.
Arterial intermittent claudication of the leg: usually affects older patients and recovers more slowly after rest.
Peripheral neuropathy (such as superficial peroneal nerve entrapment): may cause numbness, but muscle pressure testing is normal.
Patients with a history of metabolic syndrome face atherosclerosis and neurodegenerative change, and are at higher risk of developing vascular or neurological conditions. Purely neurogenic disease may stem from autoimmune disease, alcohol misuse, hypothyroidism, liver or kidney disease, viral infection, or heavy-metal poisoning such as mercury or lead.
Vitamin D deficiency, hypophosphatemia, hypocalcemia, or osteoporosis are treatable medical risk factors that warrant screening. In athletes at risk of RED-S (relative energy deficiency in sport), bone stress injury (BSI) should be considered and managed with a comprehensive approach that includes exercise, metabolic health, and strategies to strengthen bone health. Chronic exertional compartment syndrome (CECS) can present with symptoms resembling the early phase of the BSI spectrum, including periostitis and medial tibial stress.

Diagnostic tools

Measuring intracompartmental pressure is the gold standard for diagnosing compartment syndrome; measurement is usually performed with a needle manometer.
Acute compartment syndrome (ACS)
Intracompartmental pressure measurement (gold standard)
- Normal pressure under 10 mmHg
- A compartment pressure over 30 mmHg, or a difference between compartment pressure and diastolic pressure of less than 30 mmHg (delta P under 30 mmHg), supports the diagnosis.
Electromyography (EMG) or arterial ultrasound (to rule out neuropathy or vascular occlusion)
Chronic exertional compartment syndrome (CECS)
Pre- and post-exercise compartment pressure testing
- Pre-exercise pressure over 15 mmHg, or
- Over 30 mmHg 1 minute after exercise, or
- Over 20-25 mmHg 5 minutes after exercise supports the diagnosis.
- If symptoms are typical and pressure is borderline, clinicians sometimes rely on clinical judgment.
MRI or bone scan (to rule out stress fracture or other structural abnormalities)
Ultrasound to measure fascial thickness at different pressures (a few studies)

Initial treatment

Acute compartment syndrome (ACS) is a medical emergency and needs immediate treatment.
Emergency fasciotomy is the only effective treatment.
Avoid elevating the limb (which may worsen ischemia).
Avoid painkillers (NSAIDs) or excessive icing, which may interfere with monitoring blood flow.
Chronic exertional compartment syndrome (CECS)
Modify the way you exercise (such as shortening exercise time, changing footwear, or adjusting gait).
Manual therapy and myofascial release.
A 6- to 12-week course of conservative treatment is generally recommended, with an assessment of the results after 3 to 6 months. If conservative approaches are unsuccessful, referral to an orthopedic or sports medicine specialist should be made.
Surgery (fasciotomy) is for those with severe symptoms that do not improve.

Medications

Acute compartment syndrome (ACS)
Strong painkillers are not recommended, as they may mask worsening of the condition.
After surgery, an appropriate amount of painkiller may be used according to the level of pain (such as short-term acetaminophen).
Chronic exertional compartment syndrome (CECS)
NSAIDs (such as ibuprofen, naproxen) may be used short term, but most patients see no clear improvement.
No specific medication effectively treats CECS, so the focus remains on exercise modification and other measures.

Additional treatment

Acute compartment syndrome (ACS)
Conservative treatment has limited effect; the recommended treatment is fasciotomy.
Avoid the “Compression” and “Elevation” of the RICE principle, as these may worsen ischemia.
Rehabilitation focus after surgery: wound care, gradual return to activity, exercise training.
Chronic exertional compartment syndrome (CECS)
Manual therapy and exercise modification
- Change the exercise pattern, such as reducing running distance and lowering exercise intensity.
- Train core muscles and hip stability to reduce the load on the calf.
Footwear and gait adjustment
- Switch to suitable athletic shoes that provide good foot support.
- Correct gait abnormalities, such as excessive forefoot striking or a supinated foot.
Other non-surgical methods
Acupuncture, ultrasound-guided treatment, shockwave therapy, and botulinum toxin injection have a few related studies, but results vary.

Surgery

Acute compartment syndrome (ACS)
If fasciotomy is performed within 6 hours for acute compartment syndrome, full functional recovery is expected. After 6 hours of ischemia, necrosis occurs, and 6 hours is considered the accepted upper limit for tissue survival.
Surgical method: incise the anterior fascia of the lower leg to release pressure and prevent necrosis of muscle and nerve.
If treatment is delayed, it may lead to permanent muscle necrosis and contracture deformity.
After surgery, monitor for wound infection, nerve function, and recovery of limb circulation and function.
Chronic exertional compartment syndrome (CECS)
Fasciotomy is the main surgical option.
Indications: conservative treatment has failed, and symptoms severely affect athletic performance.
The success rate is about 70-90%, but there may be a risk of poor wound healing, infection, or nerve injury.
After surgery, return to exercise gradually to reduce the risk of recurrence.

Prognosis

Acute compartment syndrome (ACS)
- With timely surgery, normal function can usually be restored.
- With delayed treatment, muscle necrosis and permanent nerve injury may occur, and amputation may even be needed.
Chronic exertional compartment syndrome (CECS)
Most patients improve with conservative treatment; if symptoms persist, gait and biomechanical factors should be reassessed.
The surgical success rate is high (70-90%), but some patients may still have a risk of recurrence. Recurrent symptoms occur in about 20-30% of patients after surgery, usually due to localized muscle contraction secondary to fibrosis.

References

June 2014 The Open Orthopaedics Journal 8(1):185-93
Cureus. 2024 Jun 24;16(6):e63034.
Lancet. 2015 Sep 26;386(10000):1299-1310.
https://www.orthobullets.com/trauma/1001/leg-compartment-syndrome
https://www.mayoclinic.org/diseases-conditions/chronic-exertional-compartment-syndrome/symptoms-causes/syc-20350830
https://blogs.bmj.com/bjsm/2025/04/28/the-msk-playbook-chronic-exertional-compartment-syndrome-and-differentials-of-exercise-induced-leg-pain/