The unique characteristic of sesamoid bones is they do not have a direct connection to other bones. The largest sesamoid bone is the kneecap. There are also two small free-floating sesamoid bones located in the ball of the foot. They are about the size of a pea and help with toe movement, ambulation, and support. Pain and inflammation around these bones cause a condition called sesamoiditis that can make standing and walking painful. Orthotic inserts are an excellent treatment for this condition.