The Lower Limb

superior and the inferior pubic ramus. Each of the three parts of the pelvic bone converge to

form the acetabulum—a cup that forms the joint between the pelvis and the femur.

There are two regions that are enclosed by the bony pelvis. The superior part is called the

greater pelvic cavity or “false pelvis,” which houses the small and large intestines. Inferiorly is

the “true pelvis,” which is also referred to as the lesser pelvis. It contains the bladder and other

pelvic organs. The pelvic brim (also called the pelvic inlet) is the upper margin of the lesser

pelvis and the lower margin of the greater pelvis. The pelvic brim is known as the pelvic inlet,

while the inferior part of the lesser pelvic cavity is called the pelvic outlet.

THE LOWER LIMB

There are three regions in the lower limb: the thigh, the leg, and the foot. There are 30 bones in

the lower limb, including the femur, patella, tibia, fibula, tarsal bones, metatarsal bones, and

phalanges. Figure 47 shows the bones of the lower limb:

The femur is the only bone in the thigh. The head of the femur is the rounded proximal end that

articulates with the acetabulum to form the hip joint. The greater trochanter is on the outside

of the femur at the proximal end, while the lesser trochanter is the bony prominence on the

medial projection of the proximal femur. These are muscle attachments that move the thigh

and leg.

Distally, the femur has a lateral condyle and lateral epicondyle, as well as a medial condyle and

medial epicondyle, that help form the articular connection to the tibia and fibula at the knee

joint. The condyles form the actual joint, while the epicondyles form muscle attachments.

Between the condyles is the intercondylar fossa, which is a deep depression that the patella sits

in.

The patella or kneecap is the largest sesamoid bone in the body, being incorporated into the

tendon on the anterior part of the knee. The patella articulates with the patellar surface of the

femur, preventing rubbing of the tendon against the distal femur. It also lifts the tendon away

from the knee joint, which increases the leverage of the quadriceps femoris muscle across the

knee joint. The patella does not articulate with the tibia.

The tibia or shin bone is the medial bone of the leg—much larger than the fibula, which is its

paired bone in the lower leg. The tibia is the main weight-bearing bone of the lower leg and

can be palpated down the entire aspect of the medial leg. The proximal end has a medial and

lateral condyle that are smooth and flat, articulating with the femur to form the knee joint. The

tibial tuberosity is where the inferior patellar ligament attaches. There is a long interosseous

membrane that acts as a connection between the tibia and the fibula. At the distal end is the

medial malleolus or the medial ankle prominence.

The fibula is the small outer or lateral bone in the lower leg. It does not bear weight but acts to

attach muscles around the lower leg so it cannot be palpated, except at the proximal and distal

ends. It articulates with the lateral tibial condyle to form the proximal tibiofibular joint. The

distal end is palpated as the lateral malleolus or the outer ankle prominence.

There are seven tarsal bones that form the proximal half of the foot. The talus is the most

superior bone in the ankle and forms the ankle joint with the tibia and fibula. Inferiorly, it

connects with the calcaneus, which is the heel bone and the largest bone in the foot. The

calcaneus forms the weightbearing part of the foot. The cuboid bone, the navicular bone, and