Sesamoid Bones

Sesamoid Bones are small bones met with in the substance of tendons in the neighbourhood of certain joints. They derive their name from their resemblance to grains of sesame. In the human subject the patella is the best example; and besides it they are commonly met with on the palmar aspect of the joint which unites the metacarpal bone of the thumb with the first phalanx, and in the corresponding position in the great toe, there being two in each position, and their object to increase the leverage of the short flexor muscles of the thumb and great toe. They are much more numerous in the great majority of mammals than in man.