Anterior compartment syndrome, also known as anterior shin splints occurs when the big muscle on the outside front of the lower leg becomes too big for the sheath that surrounds it. causing pain. Here we explain both acute and chronic anterior compartment syndrome.
Symptoms of anterior compartment syndrome include:
- Pain on the outside of your shin, specifically on the large muscles called the tibialis anterior.
- You will have weakness in the muscle. Therefore trying to pull your foot upwards may be difficult.
- Symptoms may be reproduced by pulling your foot downwards, which stretches the muscle.
- In severe cases ‘foot drop’ may be seen. This is where you cannot properly lift your foot up when walking.
- Compartment syndromes can be acute (sudden onset), or chronic (gradual onset).
What is anterior compartment syndrome?
Anterior compartment syndrome relates to the big tibialis anterior muscle on the outside of the shin.
A compartment syndrome occurs when a muscle swells up within the sheath that surrounds it. This can be from bleeding or swelling within the muscle and is known as acute compartment syndrome. Or it can be chronic and occur over time when the muscle gets bigger as a result of training (hypertrophy).
What causes anterior compartment syndrome?
Acute compartment syndrome is likely to have followed a direct impact to the muscle. As a result, a contusion occurs where the muscle is crushed against the bone and bleeds. If the bleeding is contained within the muscle compartment then pressure increases causing pain.
If the bleeding is allowed to escape the muscle compartment then it drains away more easily. Therefore there is no pressure build-up within the muscle compartment. Bleeding eventually manifests as bruising seen below the surface of the skin. Acute injuries also happen as a result of a chronic compartment syndrome flaring up painfully through overuse.
Chronic compartments syndromes are similar to acute injuries but will have come on over a period of time. When muscles are put under stress they adapt and grow bigger. Overuse can cause muscles to grow too fast for the surrounding sheath to adapt. Therefore, pressure within the sheath increases resulting in pain.
In the short term, rest relieves symptoms because blood pressure within the muscle reduces. However, pain returns when you start to run again. Often at exactly the same point into a run or training session.
Anterior compartment syndrome treatment
Severe acute compartment syndrome – is a medical emergency. You should seek professional medical attention as soon as possible. This is especially true if pain gets progressively worse even you are not exercising. If you leave it then long-term damage to nerves or muscle can occur due to restricted blood flow.
Rest – for both an acute and chronic compartment syndrome rest and applying cold therapy is important. This will reduce the pain and swelling which will take the pressure off the sheath surrounding the muscle.
Ice – apply ice or cold therapy and compression for 20 minutes at a time every hour initially until the pain and swelling go down.
Taping – anterior compartment syndrome taping can provide instant relief from pain by supporting the muscle. It can be worn all the time initially whilst it is painful and later on to support the lower leg when returning to normal training.
See a professional – If your compartment syndrome is chronic then professional advice may be needed to identify the causes and advise on treatment. You may require a prolonged period of rest for a number of weeks. This should allow the muscle to atrophy or reduce in size.
Medication – a doctor may prescribe anti-inflammatory medication e.g. Ibuprofen to help with pain and swelling.
Surgery – in severe acute cases, surgery may be indicated to release the pressure within the compartment. A surgeon will measure the pressure within the muscle sheath itself. Surgery involves making a small cut or two in the muscle sheath. This releases pressure as your muscle can expand.
Orthotic inserts – If your injury is chronic then correcting any biomechanical dysfunction with orthotic inserts should be considered. Foot problems such as overpronation (where your foot rolls in or flattens too much), maybe causing the tibialis anterior muscle to work too hard. As a result, overuse and causes the muscle to grow too large for the sheath surrounding it.
Training methods, running gait, type of shoe should also be considered as the wrong type of running shoe can cause or make the condition worse. See a specialist running shoe retailer for advice on choosing running shoes for your type of feet.