The anterior compartment muscles (tibialis
anterior, extensor hallucis longus and extensor digitorum longus) hold the forefoot
up during foot descent and contract eccentrically immediately after the heel
strikes the ground. They are opposed by the much larger gastrocnemius and soleus
muscles, which pull the forefoot down. The tremendous force of eccentric contractions
can damage the anterior compartment muscles
Pain occurs in the anterior
compartment muscles, at first only immediately after the heel strikes the ground
during running. If running is continued, the pain will occur throughout each
step, eventually being felt constantly. By the time advice is sought, there
is usually severe point tenderness over the anterior compartment muscles.
Treatment includes stopping running, trying an alternate exercise, stretching
the calf muscles, and doing exercises to strengthen the anterior compartment
muscles after they start to heal.
The main function
of the posteromedial compartment muscles is to supinate the foot and raise
and evert the heel just before "toeing off". Increased traction
on the muscles is caused by excessive pronation and by running on banked tracks
or crowned roads (exacerbated by wearing shoes that do not effectively restrict
pronation). Excessive pronation causes the arch to drop lower than normal,
increasing the force necessary to lift the arch durig supination.
Pain usually starts in the postremedial compartment muscles; 2 to 20 cm above
the medial malleolus. It becomes more severe when the athlete rises up on
his toes or everts the foot. If he continues running, the pain then moves
forward to involve the medial aspect of the tibia, and can then move up the
medial side of the tibia, to reach within 5 to 10 cm of the knee.
Pain location and severity depend on injury progression. First, there is a
tendinitis of the muscles of the deep posterior compartment. If the athlete
continues to run, the pain may progress into the muscle bodies themselves;
then traction on the tibialis posterior tendon can lift the muscle from its
bony origin, causing subperiosteal hamorrhage and periostitis. With continued
traction, part of the tibia can be torn away.
2006 Sima Soltani D.P.M., All Rights Reserved - Foot Doctor
Irvine & Laguna Hills