I have a lot of people ask me to describe the Sesamoid Bone in more detail.  So I figured I would put together a quick article on the bone itself, how it is formed and why it is so different from all of the other bones that make up our skeletal mass.  Sesamoid bones are found in numerous places within the body, however, the sesamoid bones found in the foot seem to catch most of the attention. 


Anatomy tells us that the sesamoid bone is a bone that is embedded within a tendon.  Very interesting.  Most bones are connected to other bones, they are not free standing, nor are they simply hidden within a tendon.  Sesamoids are really interesting in this way.  The sesamoid bone is found in areas where a tendon passes over a joint of some kind.  Joints that have sesamoid bones are the hand, knee and foot. sesamoid bone


Of course, you’re probably wondering what possible purpose a free standing bone held within a tendon could have?  Well, the purpose of the sesamoid bone is to protect the tendon and to bolster its effect from a mechanical standpoint.  The sesamoid bone’s job is to position the tendon just slightly farther from the center of the joint.  The purpose of doing this is to increase the moment arm of the joint tendon.  The sesamoid bone also serves as a prevention method against the flattening of the tendon into the joint as tension ratchets up.  This prevention serves a dual purpose, and also creates a consistent moment arm throughout the many varieties of tendon loads that are experienced in a normal range of motion. 


If you are curious exactly where the sesamoid bones can be located,  one can be found in the knee, within the quadriceps tendon of the patella.  Another can be found in the hand.  The sesamoid bones of the hand are typically located in the distal parts of the first metacarpal.  There are however also sesamoid bones found in the second metacarpal, although, this is seen less frequently.  As previously mentioned, the most famous of the sesamoid bones are found in the foot.  This bone is located near the first metatarsal bone (the big toe).  Generally there are two sesamoid bones found here, however, in a few cases, only one bone has been found.


The reason the sesamoid bone in the foot has received so much notoriety, is that it is linked with the disease sesamoiditis.  Sesamoiditis is a condition where by the tendon surrounding the sesamoid bone becomes inflamed and irritated.  Due to the relative closeness of the sesamoid bone to the ball of the foot and the big toe, any activity that overuses either of these parts of the foot can cause sesamoiditis.  The ailment typically causes a general sense of discomfort and pain in afflicted individuals. If you are experiencing this sensation, try out the Silipos Softzone Pure Gel Gel Metatarsal Pad


Have you had an experience with sesamoiditis?  Share it below!