The Anatomy of the Human Leg Bones

The human leg contains several bones that provide various functions. This limb is commonly used to refer to the entire leg even though it technically is only part of the leg between the knee and ankle, according to TheFreeDictionary.com. Both the upper and lower parts of the human leg work together to support the body and help with movement.

Thigh

• The upper part of the human leg is composed of a long bone called the femur. The femur--or thigh bone--connects to the pelvis to form the hip joint and meets the lower leg's shin bone at the knee joint, according to HealthLine.com. The femur has a concavity or groove that allows the knee joint to rise up during straightening of the knee, called extension, and to move downward during bending of the knee, called flexion.

Hip

• The hip is a ball-and-socket joint that allows the head of the femur--the ball--to fit snugly into the acetabulum--the socket--of the pelvis. Because of this fit, the hip joint is very stable and helps to disperse the forces the human body exerts when involved in weight-bearing activities. In fact, the hip muscles can bring the leg up toward the body, away from the body, to the side of the body and toward the body's midline.

Knee

• The knee joint of the human leg involves the femur, shin bone and patella--also known as the kneecap. The patella is located inside the tendon of a muscle called the rectus femoris muscle, which connects the femur to the shin bone. The underside area of the patella has many ridges that receive protection from cartilage. The patella's responsibility is to give the muscles on the front of the thigh increased efficiency and to protect the front of the femur.

Lower Leg

• The bones of the lower part of the human leg include the tibia and the fibula. The tibia is the shin bone, while the fibula is the calf bone. The tibia actually carries all of the body's weight and is the leg's main bone, according to Free-Online-Health.com. The fibula, which runs parallel to the tibia, acts as more of a stabilizer and forms the bony projection on the outside of the ankle, called the lateral malleolus. The tibia, which is covered by a very thin tissue, is located more toward the midline of the body while the fibula is located toward the outside of the lower leg, according to the Gale Group Inc. These bones work together to form the ankle joint.

Ankle

• The tibia sits atop the ankle bone, called the talus, which fits into the heel bone, called the calcaneus. The calcaneus, the largest bone in the foot, absorbs a large amount of the force exerted when the lower leg moves. The tibia, fibula and talus are secured by a protective structure known as the synovial capsule, which encloses the joint in a lubricating fluid. The foot's bones mirror those of the human hand.