A bone that is within a joint capsule or tendon. The sesamoids
in the foot are usually located under the big toe joint (first metatarsophalangeal joint/MTPJ). There are usually just two sesamoids, but occasionally one of the sesamoids may be in two pieces (bipartite) or even three pieces (tripartite). Sesamoids can also occur under the 2nd through 5th metatarsophalangeal joints and are located in other areas of the body as well.