The common name for the bone known as the femur is the thigh bone. It is the longest bone in the human body and connects the hip joint to the knee joint. The femur plays a crucial role in supporting the weight of the body during activities like walking and running. Its strong structure is essential for maintaining stability and balance. The femur also serves as an attachment point for various muscles, ligaments, and tendons, facilitating movement and exertion. Fractures to the femur can be serious and often require medical intervention.