Femur

The femur plays a critical role in the body's locomotion and stability. As the main weight-bearing bone of the thigh, it supports the entire weight of the upper body during activities like standing, walking, and climbing. When the muscles contract through the pelvis and knee joint, the femur acts as a lever, enabling efficient movement. The bone also facilitates the attachment of major muscles, including the quadriceps in the front of the thigh and the hamstrings at the back, which are essential for bending and extending the knee. Notably, the femur contributes to the hip joint, forming a ball-and-socket joint with the pelvis, allowing for a significant range of motion, including rotation. Moreover, it houses the bone marrow, which is essential for producing blood cells, thereby playing a vital role in the circulatory system.

The femur is situated in the upper leg, extending from the hip joint to the knee joint. It originates at the acetabulum of the pelvis, where it fits into the socket to form the hip joint, extending downward to the knee joint, where it connects with the tibia and patella. This positioning allows the femur to not only support the weight of the body but also to make contact with both the pelvis and the knee, acting as a central structure in the leg anatomy. Its proximal end is characterized by the rounded femoral head that articulates with the pelvic girdle, while the distal end flares into two condyles that articulate with the knee joint.

• The femur can support up to 30 times the weight of a person's body.
• The femur is involved in both walking and running due to its crucial role at the hip and knee joints.
• In certain cultures, the femur has been used for various traditional practices, such as making tools and musical instruments.