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
Occipitofrontalis muscle Occipitofrontalis muscle The occipitofrontalis muscle (epicranius muscle) is a muscle which covers parts of the skull. It consists of two parts or bellies: The occipital belly, near the occipital bone, and the frontal belly, near the frontal bone. In humans, the occipitofrontalis only serves for facial expressions. Some sources consider the occipital and frontal bellies to be two distinct muscles. However, Terminologia Anatomica currently classifies it as a single muscle, and also includes the temporoparietalis muscle as part of the epicranius. The occipitofrontalis muscle receives blood from several arteries. The frontal belly receives blood from the supraorbital and supratrochlear arteries,