Sesamoid bones, Functions and mechanism of action.

The sesamoid bone is a small rounded bone embedded within a tendon that usually passes over a joint (Sesamoid bones are the bones not connected to any other bone).The largest sesamoid bobe is the patella.

Latin........."ossa sesamoidea"

Sesamoid bones functions probably are to modify pressure, to diminish friction, and occasionally to alter the direction of a muscle pull.Sesamoid bones also prevent the tendon from flattening into the joint as tension increases and therefore also maintain a more consistent moment arm through a variety of possible tendon loads.
Sesamoid bones can be found in the knee, hand and foot...

Sesamoid bones at the distal end of the first metatarsal bone of the foot.

Sesamoids act like pulleys. They provide a smooth surface over which the tendons slide, so they increase the ability of the tendons to transmit muscle forces. The sesamoids in the forefoot also assist with weightbearing and help elevate the bones of the big toe.