Anterior compartment syndrome in common terms refer to the pain suffered by runners, especially, distance runners (which is why it is often designated as part of 'the distance runners’ epidemic') in the front of the lower leg. To further categorize it, this syndrome belongs to one of the four categories of shin splints, the other three being, medial tibial stress syndrome, stress factures, and tibial periostitis.
This syndrome is further divided into two categories.
acute stage which is considered a medical emergency and requires immediate medical attention. This problem will occur with little to no exertion.
chronic stage generally occurs during exertion but will quickly subside once the activity has ended. It is also known as exertional compartment syndrome.
The muscles forming in the lower legs are enclosed in a 'compartment' known as fascia. This covering has a consistency typical of saran wrap. During exercises, these muscles exhibit a tendency to enlarge as do muscles being exercised, along with increased blood flow which also causes muscle to swell. The function of the compartment is to resist this swelling and while performing this function, the pressure builds up within the the compartment. This in turn tends to restrict the flow of blood to the muscles and this results in a constriction that presents itself in the form of pain. The pain is localized on the front of the lower leg, on the outer side of the shin bone. The muscle involved here is the tibialis anterior muscle whose function is to help lift the foot upward.
Anterior compartment syndrome may be caused when there is an excessive tightness on the calf muscles which then forces the anterior leg muscles to work harder to compensate. The resultant stress to the tibialis anterior muscle increases the probabilities of causing anterior compartment syndrome which can take place in two phases during the running regime.
Immediately after the 'toe off', the foot flexes upward via the tibialis anterior muscle and the other 'extensor muscles' to clear the ground during the process of lifting the knee. This is responsible for the first phase of injury. The second phase is either during or immediately after the foot contacts the ground known as heel strike. At this stage, the anterior muscles work to slow down and stop the downward motion of the foot as it comes down to the ground. This is when the second phase of the injury tends to occur.
Other causes of anterior compartment syndrome include:
Stress fractures of the lower leg may mimic compartment syndrome, and normally show themselves up as small cracks (medically known as micro fractures). This condition is essentially due to repetitive low grade impacts of running, or in those who participate in aerobic sports. Medically two theories exist, overload and fatigue theories are cited as the causes for the stress fractures leading to pain in the lower leg.
When there is a pain which is localized to a small portion of the bone, it is normally due to the occurrence of a stress fracture. Nonetheless, an X-Ray, bone scan, or mri is necessary to confirm this diagnosis.
Compartment syndrome is usually diagnosed by measuring the pressure within the compartment, both at rest and during exercise.
It is also worth pointing out that in addition to occurring on the anterior portion of the lower leg, compartment syndrome may also occur on the back of the leg as well as the outside of the leg. Both of these conditions occur less frequently.
Treatment for chronic compartment syndrome include:
Treatment for acute compartment syndrome is a totally different scenario. The signs and symptoms of acute compartment syndrome are known as the 5 P's.
As stated previously, this is considered a medical emergency and immediate medical care is required. In the majority of these cases the fascia covering the compartment has to be incised in order to relieve the pressure. Failure to do so may result in tissue death to the foot due to lack of blood flow and nerve sensation.
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