The lower limb is divided into three regions. These are the thigh, located between the hip and knee joints; the leg, located between the knee and ankle joints; and distal to the ankle, the foot. There are 30 bones in each lower limb. These are the femur, patella, tibia, fibula, seven tarsal bones, five metatarsal bones, and 14 phalanges.
The femur is the single bone of the thigh. Its rounded head articulates with the acetabulum of the hip bone to form the hip joint. The head has the fovea capitis for attachment of the ligament of the head of the femur. The narrow neck joins inferiorly with the greater and lesser trochanters. Passing between these bony expansions are the intertrochanteric line on the anterior femur and the larger intertrochanteric crest on the posterior femur. On the posterior shaft of the femur is the gluteal tuberosity proximally and the linea aspera in the mid-shaft region. The expanded distal end consists of three articulating surfaces: the medial and lateral condyles, and the patellar surface. The outside margins of the condyles are the medial and lateral epicondyles. The adductor tubercle is on the superior aspect of the medial epicondyle.
The patella is a sesamoid bone located within a muscle tendon. It articulates with the patellar surface on the anterior side of the distal femur, thereby protecting the muscle tendon from rubbing against the femur.
The leg contains the large tibia on the medial side and the slender fibula on the lateral side. The tibia bears the weight of the body, whereas the fibula does not bear weight. The interosseous border of each bone is the attachment site for the interosseous membrane of the leg, the connective tissue sheet that unites the tibia and fibula.
The proximal tibia consists of the expanded medial and lateral condyles, which articulate with the medial and lateral condyles of the femur to form the knee joint. Between the tibial condyles is the intercondylar eminence. On the anterior side of the proximal tibia is the tibial tuberosity, which is continuous inferiorly with the anterior border of the tibia. On the posterior side, the proximal tibia has the curved soleal line. The bony expansion on the medial side of the distal tibia is the medial malleolus. The groove on the lateral side of the distal tibia is the fibular notch.
The head of the fibula forms the proximal end and articulates with the underside of the lateral condyle of the tibia. The distal fibula articulates with the fibular notch of the tibia. The expanded distal end of the fibula is the lateral malleolus.
The posterior foot is formed by the seven tarsal bones. The talus articulates superiorly with the distal tibia, the medial malleolus of the tibia, and the lateral malleolus of the fibula to form the ankle joint. The talus articulates inferiorly with the calcaneus bone. The sustentaculum tali of the calcaneus helps to support the talus. Anterior to the talus is the navicular bone, and anterior to this are the medial, intermediate, and lateral cuneiform bones. The cuboid bone is anterior to the calcaneus.
The five metatarsal bones form the anterior foot. The base of these bones articulate with the cuboid or cuneiform bones. The metatarsal heads, at their distal ends, articulate with the proximal phalanges of the toes. The big toe (toe number 1) has proximal and distal phalanx bones. The remaining toes have proximal, middle, and distal phalanges.
adductor tubercle
small, bony bump located on the superior aspect of the medial epicondyle of the femur
ankle joint
joint that separates the leg and foot portions of the lower limb; formed by the articulations between the talus bone of the foot inferiorly, and the distal end of the tibia, medial malleolus of the tibia, and lateral malleolus of the fibula superiorly
anterior border of the tibia
narrow, anterior margin of the tibia that extends inferiorly from the tibial tuberosity
base of the metatarsal bone
expanded, proximal end of each metatarsal bone
calcaneus
heel bone; posterior, inferior tarsal bone that forms the heel of the foot
cuboid
tarsal bone that articulates posteriorly with the calcaneus bone, medially with the lateral cuneiform bone, and anteriorly with the fourth and fifth metatarsal bones
distal tibiofibular joint
articulation between the distal fibula and the fibular notch of the tibia
femur
thigh bone; the single bone of the thigh
fibula
thin, non-weight-bearing bone found on the lateral side of the leg
fibular notch
wide groove on the lateral side of the distal tibia for articulation with the fibula at the distal tibiofibular joint
foot
portion of the lower limb located distal to the ankle joint
fovea capitis
minor indentation on the head of the femur that serves as the site of attachment for the ligament to the head of the femur
gluteal tuberosity
roughened area on the posterior side of the proximal femur, extending inferiorly from the base of the greater trochanter
greater trochanter
large, bony expansion of the femur that projects superiorly from the base of the femoral neck
hallux
big toe; digit 1 of the foot
head of the femur
rounded, proximal end of the femur that articulates with the acetabulum of the hip bone to form the hip joint
head of the fibula
small, knob-like, proximal end of the fibula; articulates with the inferior aspect of the lateral condyle of the tibia
head of the metatarsal bone
expanded, distal end of each metatarsal bone
hip joint
joint located at the proximal end of the lower limb; formed by the articulation between the acetabulum of the hip bone and the head of the femur
intercondylar eminence
irregular elevation on the superior end of the tibia, between the articulating surfaces of the medial and lateral condyles
intercondylar fossa
deep depression on the posterior side of the distal femur that separates the medial and lateral condyles
intermediate cuneiform
middle of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the medial cuneiform bone, laterally with the lateral cuneiform bone, and anteriorly with the second metatarsal bone
interosseous border of the fibula
small ridge running down the medial side of the fibular shaft; for attachment of the interosseous membrane between the fibula and tibia
interosseous border of the tibia
small ridge running down the lateral side of the tibial shaft; for attachment of the interosseous membrane between the tibia and fibula
interosseous membrane of the leg
sheet of dense connective tissue that unites the shafts of the tibia and fibula bones
intertrochanteric crest
short, prominent ridge running between the greater and lesser trochanters on the posterior side of the proximal femur
intertrochanteric line
small ridge running between the greater and lesser trochanters on the anterior side of the proximal femur
knee joint
joint that separates the thigh and leg portions of the lower limb; formed by the articulations between the medial and lateral condyles of the femur, and the medial and lateral condyles of the tibia
lateral condyle of the femur
smooth, articulating surface that forms the distal and posterior sides of the lateral expansion of the distal femur
lateral condyle of the tibia
lateral, expanded region of the proximal tibia that includes the smooth surface that articulates with the lateral condyle of the femur as part of the knee joint
lateral cuneiform
most lateral of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the intermediate cuneiform bone, laterally with the cuboid bone, and anteriorly with the third metatarsal bone
lateral epicondyle of the femur
roughened area of the femur located on the lateral side of the lateral condyle
lateral malleolus
expanded distal end of the fibula
leg
portion of the lower limb located between the knee and ankle joints
lesser trochanter
small, bony projection on the medial side of the proximal femur, at the base of the femoral neck
ligament of the head of the femur
ligament that spans the acetabulum of the hip bone and the fovea capitis of the femoral head
linea aspera
longitudinally running bony ridge located in the middle third of the posterior femur
medial condyle of the femur
smooth, articulating surface that forms the distal and posterior sides of the medial expansion of the distal femur
medial condyle of the tibia
medial, expanded region of the proximal tibia that includes the smooth surface that articulates with the medial condyle of the femur as part of the knee joint
medial cuneiform
most medial of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, laterally with the intermediate cuneiform bone, and anteriorly with the first and second metatarsal bones
medial epicondyle of the femur
roughened area of the distal femur located on the medial side of the medial condyle
medial malleolus
bony expansion located on the medial side of the distal tibia
metatarsal bone
one of the five elongated bones that forms the anterior half of the foot; numbered 1–5, starting on the medial side of the foot
metatarsophalangeal joint
articulation between a metatarsal bone of the foot and the proximal phalanx bone of a toe
navicular
tarsal bone that articulates posteriorly with the talus bone, laterally with the cuboid bone, and anteriorly with the medial, intermediate, and lateral cuneiform bones
neck of the femur
narrowed region located inferior to the head of the femur
patella
kneecap; the largest sesamoid bone of the body; articulates with the distal femur
patellar surface
smooth groove located on the anterior side of the distal femur, between the medial and lateral condyles; site of articulation for the patella
phalanx bone of the foot
(plural = phalanges) one of the 14 bones that form the toes; these include the proximal and distal phalanges of the big toe, and the proximal, middle, and distal phalanx bones of toes two through five
proximal tibiofibular joint
articulation between the head of the fibula and the inferior aspect of the lateral condyle of the tibia
shaft of the femur
cylindrically shaped region that forms the central portion of the femur
shaft of the fibula
elongated, slender portion located between the expanded ends of the fibula
shaft of the tibia
triangular-shaped, central portion of the tibia
soleal line
small, diagonally running ridge located on the posterior side of the proximal tibia
sustentaculum tali
bony ledge extending from the medial side of the calcaneus bone
talus
tarsal bone that articulates superiorly with the tibia and fibula at the ankle joint; also articulates inferiorly with the calcaneus bone and anteriorly with the navicular bone
tarsal bone
one of the seven bones that make up the posterior foot; includes the calcaneus, talus, navicular, cuboid, medial cuneiform, intermediate cuneiform, and lateral cuneiform bones
thigh
portion of the lower limb located between the hip and knee joints
tibia
shin bone; the large, weight-bearing bone located on the medial side of the leg
tibial tuberosity
elevated area on the anterior surface of the proximal tibia
Watch this video to view how a fracture of the mid-femur is surgically repaired. How are the two portions of the broken femur stabilized during surgical repair of a fractured femur?
A hole is drilled into the greater trochanter, the bone marrow (medullary) space inside the femur is enlarged, and finally an intramedullary rod is inserted into the femur. This rod is then anchored to the bone with screws.
Visit this site to perform a virtual knee replacement surgery. The prosthetic knee components must be properly aligned to function properly. How is this alignment ensured?
Metal cutting jigs are attached to the bones to ensure that the bones are cut properly prior to the attachment of prosthetic components.
Use this tutorial to review the bones of the foot. Which tarsal bones are in the proximal, intermediate, and distal groups?
The proximal group of tarsal bones includes the calcaneus and talus bones, the navicular bone is intermediate, and the distal group consists of the cuboid bone plus the medial, intermediate, and lateral cuneiform bones.
View this link to learn about a bunion, a localized swelling on the medial side of the foot, next to the first metatarsophalangeal joint, at the base of the big toe. What is a bunion and what type of shoe is most likely to cause this to develop?
A bunion results from the deviation of the big toe toward the second toe, which causes the distal end of the first metatarsal bone to stick out. A bunion may also be caused by prolonged pressure on the foot from pointed shoes with a narrow toe box that compresses the big toe and pushes it toward the second toe.
1. Which bony landmark of the femur serves as a site for muscle attachments?
A) fovea capitis
B) lesser trochanter
C) head
D) medial condyle
B
2. What structure contributes to the knee joint?
A) lateral malleolus of the fibula
B) tibial tuberosity
C) medial condyle of the tibia
D) lateral epicondyle of the femur
C
3. Which tarsal bone articulates with the tibia and fibula?
A) calcaneus
B) cuboid
C) navicular
D) talus
D
4. What is the total number of bones found in the foot and toes?
A) 7
B) 14
C) 26
D) 30
C
5. The tibia ________.
A) has an expanded distal end called the lateral malleolus
B) is not a weight-bearing bone
C) is firmly anchored to the fibula by an interosseous membrane
D) can be palpated (felt) under the skin only at its proximal and distal ends
C
1. Define the regions of the lower limb, name the bones found in each region, and describe the bony landmarks that articulate together to form the hip, knee, and ankle joints.
The lower limb is divided into three regions. The thigh is the region located between the hip and knee joints. It contains the femur and the patella. The hip joint is formed by the articulation between the acetabulum of the hip bone and the head of the femur. The leg is the region between the knee and ankle joints, and contains the tibia (medially) and the fibula (laterally). The knee joint is formed by the articulations between the medial and lateral condyles of the femur, and the medial and lateral condyles of the tibia. Also associated with the knee is the patella, which articulates with the patellar surface of the distal femur. The foot is found distal to the ankle and contains 26 bones. The ankle joint is formed by the articulations between the talus bone of the foot and the distal end of the tibia, the medial malleolus of the tibia, and the lateral malleolus of the fibula. The posterior foot contains the seven tarsal bones, which are the talus, calcaneus, navicular, cuboid, and the medial, intermediate, and lateral cuneiform bones. The anterior foot consists of the five metatarsal bones, which are numbered 1–5 starting on the medial side of the foot. The toes contain 14 phalanx bones, with the big toe (toe number 1) having a proximal and a distal phalanx, and the other toes having proximal, middle, and distal phalanges.
2. The talus bone of the foot receives the weight of the body from the tibia. The talus bone then distributes this weight toward the ground in two directions: one-half of the body weight is passed in a posterior direction and one-half of the weight is passed in an anterior direction. Describe the arrangement of the tarsal and metatarsal bones that are involved in both the posterior and anterior distribution of body weight.
The talus bone articulates superiorly with the tibia and fibula at the ankle joint, with body weight passed from the tibia to the talus. Body weight from the talus is transmitted to the ground by both ends of the medial and lateral longitudinal foot arches. Weight is passed posteriorly through both arches to the calcaneus bone, which forms the heel of the foot and is in contact with the ground. On the medial side of the foot, body weight is passed anteriorly from the talus bone to the navicular bone, and then to the medial, intermediate, and lateral cuneiform bones. The cuneiform bones pass the weight anteriorly to the first, second, and third metatarsal bones, whose heads (distal ends) are in contact with the ground. On the lateral side, body weight is passed anteriorly from the talus through the calcaneus, cuboid, and fourth and fifth metatarsal bones. The talus bone thus transmits body weight posteriorly to the calcaneus and anteriorly through the navicular, cuneiform, and cuboid bones, and metatarsals one through five.