Sesamoid bones are small, rounded bones embedded in tendons, typically in the feet, hands, and knees. The word "sesamoid" is pronounced /ˈsɛsəmɔɪd/ and spelled with a double "s" and "m" just like the word "sesame." The "oid" at the end of the word means "resembling" or "like," highlighting the small size and rounded shape of these bones. Although often overlooked, sesamoid bones play an important role in the biomechanics of our limbs and can cause pain if they become injured or inflamed.
Sesamoid bones are a type of small, round bones that are embedded within tendons or joint capsules. These bones are unique because they exist solely in certain locations where tendons or ligaments pass over or around a joint. They are generally small in size, ranging from a few millimeters to a few centimeters in diameter, and are typically flat or oval in shape. The name "sesamoid" is derived from the resemblance of these bones to the shape and size of a sesame seed.
The primary function of sesamoid bones is to improve the efficiency of certain movements by altering the angle of insertion of a tendon or providing a smooth surface for tendon gliding. They act as protective structures, helping to reduce wear and tear on delicate tendons by increasing their leverage and decreasing friction during joint movement. Sesamoid bones can be found in various parts of the body such as the hands, feet, and knees.
Common examples of sesamoid bones include the patellae (kneecaps), located within the quadriceps tendon of the knee joint, and the small sesamoid bones located under the joint of the big toe. While sesamoid bones are present in most individuals, their size and number can vary from person to person. They are integral components of the musculoskeletal system, contributing to the smooth functioning and protection of joints and tendons.
The word "sesamoid" originates from the Latin phrase "sesamum" which means "sesame seed". "Sesamoid bones" are small, seed-shaped bones that resemble sesame seeds. They got their name due to their resemblance to sesame seeds and their embedded position within tendons, similar to how sesame seeds are embedded in the pods.