What type of bones are typically found at complex joints?

Complex joints, such as the knee or shoulder joints, are characterized by their multifaceted structure which allows for a greater range of motion and multiple functions. Irregular bones are particularly suited to these complex joints due to their unique shapes and structures that enable them to fit snugly with other bones, providing stability and support while allowing for flexibility.

Irregular bones, such as the vertebrae and certain bones in the skull, can have various projections and recesses that allow for complex articulations. This complexity is important in joints that endure significant stress and require a high degree of mobility, making irregular bones central to their function.

Other types of bones, such as flat bones, small bones, and sesamoid bones, do not typically possess the same intricate shapes needed to efficiently form these complex joint structures. Flat bones, for example, serve different functions such as providing protection and are not primarily involved in joint formation. Small bones tend to refer to bones like those found in the hands and feet, which have a different arrangement and function within simpler joints. Sesamoid bones, like the patella, are specialized bones that develop within tendons but are not primarily categorized as making complex joints.