Muhammad Ali, original name Cassius Marcellus Clay, Jr. (born January 17, 1942, Louisville, Kentucky, U.S.), American professional boxer and social activist. Ali was the first fighter to win the world heavyweight championship on three separate occasions; he successfully defended this title 19 times.
The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia and patella forming the knee joint. By most measures the femur is the strongest bone in the body. The femur is also the longest bone in the body.