Gastrocnemius muscle insertion via the Achilles tendon. The plantaris muscle and a portion of its tendon run between the two muscles, which is involved in "locking" the knee from the standing position. Since the anterior compartment of the leg is lateral to the tibia, the bulge of muscle medial to the tibia on the anterior side is actually the posterior compartment. The soleus is superficial to the mid-shaft of the tibia. 10% to 30% of individuals have a sesamoid bone called the "fabella" in the lateral (outer) head of gastrocnemius muscle. Along with the soleus muscle, the gastrocnemius forms half of the
Coffin bone Coffin bone The coffin bone, also known as the pedal bone (U.S.), is the bottommost bone in the equine leg and is encased by the hoof capsule. Also known as the distal phalanx, third phalanx, or "P3". The coffin bone meets the short pastern bone or second phalanx at the coffin joint. The coffin bone is connected to the inner wall of the horse hoof by a structure called the laminar layer. The insensitive laminae coming in from the hoof wall connects to the sensitive laminae layer, containing the blood supply and nerves, which is attached to the coffin bone.