236
UNIT TWO
body weight. The lateral malleolus articulates with the ankle
and protrudes on the lateral side.
Foot
The foot is made up of the ankle, the instep, and the toes.
The ankle or
tarsus
(tahr
sus) is composed of seven
tarsal
bones.
One of these bones, the
talus
(ta
lus), can move
freely where it joins the tibia and F
bula, forming the ankle.
The other tarsal bones are firmly bound, supporting the
talus.
Figures 7.53
and
7.54
name the bones of the tarsus.
The largest of the tarsals, the
calcaneus
(kal-ka
ne-us),
or heel bone, is below the talus where it projects backward to
form the base of the heel. The calcaneus helps support body
weight and provides an attachment, the
calcaneal tuberosity,
for muscles that move the foot.
The instep or
metatarsus
(met
ah-tahr
sus) consists of
F ve elongated
metatarsal bones,
which articulate with the tar-
sus. They are numbered 1 to 5, beginning on the medial side
Fibula
The
f
bula
is a long, slender bone located on the lateral side
of the tibia. Its ends are slightly enlarged into a proximal
head
and a distal
lateral malleolus
(F g. 7.52)
.
The head artic-
ulates with the tibia just below the lateral condyle; however,
it does not enter into the knee joint and does not bear any
The skeleton is particularly vulnerable to injury during the turbu-
lent teen years, when bones grow rapidly. Athletic teens sometimes
develop Osgood-Schlatter disease, which is a painful swelling of
a bony projection of the tibia below the knee. Overusing the thigh
muscles to straighten the lower limb irritates the area, causing the
swelling. Usually a few months of rest and no athletic activity allows
the bone to heal on its own. Rarely, a cast must be used to immobilize
the knee.
Lateral
condyle
Medial
condyle
Intercondylar
fossa
Medial
epicondyle
Patellar
surface
Lateral
epicondyle
Greater
trochanter
Gluteal
tuberosity
Lesser
trochanter
Neck
Head
Fovea capitis
(a)
(b)
Linea
aspera
FIGURE 7.51
Right femur. (
a
) Anterior surface. (
b
) Posterior surface.
FIGURE 7.52
Bones of the right leg, anterior view.
Medial
malleolus
Tibia
Tibial
tuberosity
Anterior
crest
Medial
condyle
Intercondylar
eminence
Lateral
malleolus
Lateral
condyle
Head of
fibula
Fibula
previous page 266 David Shier Hole's Human Anatomy and Physiology 2010 read online next page 268 David Shier Hole's Human Anatomy and Physiology 2010 read online Home Toggle text on/off