To better understand medial tibial stress syndrome, it helps to understand the anatomy of the leg.

The entire leg contains four bones:

• Femur:
• The thighbone
• Patella:
• The kneecap
• Tibia:
• A thick bone in the front of the lower leg
• Fibula:
• A thin bone on the side of the lower leg

The lower leg contains two long bones, called the tibia and fibula. The front of the tibia is called the shin. The muscles of the lower leg control movement of the foot and ankle.

Leg anatomy examples:

• Muscles and bones of the leg
• Regions of the lower leg where tenderness may be a sign of a fracture

The tibialis posterior muscle is a large muscle, located in the front of the lower leg. It raises the ankle and turns the ankle inward.