In this lecture, we’re going to look at the
surface anatomy and osteology of the lower limb,
which will set you up to the remaining
lectures in this part of the course
which covers lower limb anatomy. So we’re going to,
first of all, start with the surface anatomy
and look at the various regions of the lower
limb, the gluteal, thigh, leg, and foot.
And then we’re going to look at the bones that
make up the lower limb.
We’ll look at the hip bone, the ischium, pubis, and ilium
and then we’ll look at the femur, the tibia,
fibula, the tarsal bones, the metatarsals, and phalanges.
We’ll look at a numerous bony landmarks on each of these individual bones
and then we’ll consider some movements
that are possible with the lower limb.
So you should be familiar with the general body
plan that we have and previously, we looked at
the bones and the muscles that form the upper
limb or the superior appendicular skeleton.
And now, we’re really associated with the lower
limb which we can see here. We’ve got the
lower limb forming by the thigh and the leg
which we’ll talk about. But what we can see
on the screen here are some surface features
of the lower limb, the inferior appendicular
skeleton. So we have the anterior surface
here and we have the posterior surface here.
So we can see the inferior appendicular skeleton
forms the lower limb, and it is specialized
for locomotion, for movement.
It’s also specialized to maintain balance, maintaining
posture, and supporting the body’s weight.
Unlike the upper limb, it contains a number
of specialized joints. It is attached to the
axial skeleton via the pelvic girdle. And we can see
on the screen on this anterior and posterior
view, we can see we have the gluteal region.
This is really only observed on the posterior
aspect here. We can imagine where the sacrum
would be and we have the gluteal fold separating
the inferior aspect of the gluteal region
from the posterior aspect of the thigh.
And here, we have a small little protrusion which is
the greater trochanter. You can see that on
the posterior surface here laterally, and also
laterally, here on this anterior surface.
And this is where we have the anterior region
of the thigh. We can see sartorius muscle
will be passing down in this direction, and
we can see it’s originating from the anterior
superior iliac spine. We can see the inguinal
ligament is passing down towards the
pubic tubercle. We can see we’ve got the impression
of the knee and the patella anteriorly in
this lower limb, and we can see where we have
the head of the fibula and the tibial tuberosity.
We can also see the fibula head protruding
laterally on this posterior view.
We can see the bulk of muscle on the posterior leg formed
by gastrocnemius and we can also appreciate
a very sharp anterior border of the tibia.
And then we pass down into the foot.
We go past both the medial and the lateral malleolus
which can be palpated. And then we move on
to the dorsum of the foot, and underneath,
we have the sole. So some regions and some
key surface landmarks. Now, the axial skeleton,
remember, is what supports the body, the core
of the body. And attached to the axial skeleton,
we have the appendicular skeleton, the superior
appendicular skeleton being for the upper
limb, and the inferior appendicular skeleton
being for the lower limb. We can see on the
skeleton here the inferior appendicular skeleton.
We have the femur, which articulates with
the hip bone via the head of the femur.
And we can see this is deviated medially towards
the midline. So we have this obliquely running
long bone, the femur. We can see it articulates
the knee joints with the tibia, which is
orientated vertically. And we have this running down
towards the ankle joint. Running anterior
to the femur, we have the patella which we can
see here and running lateral to the tibia,
we have the fibula. The fibula isn’t necessarily
involved in weight bearing, but the fibula
alongside the interosseous membrane joining
the two bones offers a large surface area
for muscle attachments. We then have a whole
series of tarsal bones. These are analogous to the carpal
bones in the wrist. And then we have metatarsals
just like we had metacarpals. Then finally,
the digits of the foot are formed by the phalanges.
So let’s move on to looking at some of the
important features of these bones. We’ll
start off with the hip bone. And the hip bone
is actually formed by three bones that are
fused together primarily at the acetabulum.
And we can see here we have a medial surface view,
and here, we would have the anterior aspect.
We’ve got the pubic symphysis surface here,
and we’ve got the posterior surface here.
This side is a lateral surface. So we have
the anterior aspect here, and we have the
posterior aspect here. And this is a superior
surface looking down. So anteriorly, it would
be here. Posteriorly, it would be here. And
this will be the medial surface. And we could
make out the ischium, the ilium, and the pubis
for all of these bones. Let’s start by looking
at the ilium. We can see the ilium is this
large wing-shaped bone. It’s the most superior
and largest of the three bones, and it forms
the superior part of the acetabulum.
So if we look here on the lateral surface, this
is all ilium here, and we can see it’s actually
going to form the superior parts of the acetabulum.
So a line going in approximately this direction
here would be the separation of the ilium with
the ischium and the pubis. So this line
here is separating the ilium above. The body
of the ilium, if we have a look here, on the
lateral surface, we can see the body of the
ilium. We can see it here with the superior
surface, the body of the ilium, and that’s
joining to the pubis and the ischium at the
acetabulum like I said. Then we have this
large wing of the ilium, and we can see two
parts of that. We can see the ala here, this
large flat surface. And then at the top of
this wing, we can see we have the iliac crest.
We can see the iliac crest is running over
here. See, on the lateral surface, we can
also see on this medial surface. Within the
iliac crest, we can see on the superior surface,
there are a couple of features. So if we look
for the bony landmarks of the ilium. Then
most anteriorly, we can see it here on this
medial surface, we’ve got the anterior superior
iliac spine. So, the iliac crest is coming
around the top, and it finishes here as the
anterior superior iliac spine. Inferior, we
have an anterior inferior iliac spine. And
these bony landmarks are important because
they offer attachment sites for muscles. More
posteriorly, we’ll find we have the posterior
superior iliac spine, and then below it, we’ll
have the posterior inferior iliac spine.
And we can see this on this medial surface.
We can also see them on the lateral surface.
Here’s the anterior superior iliac spine,
anterior inferior iliac spine. And here we
have our two posterior iliac spines. And we
could make them out on this superior view
as well. If we were to just look at the lateral
surface of the ilium, then this is important
because it gives rise to attachments for gluteus
maximus. In order to be comfortable with the
attachments of gluteus maximus, we need to
be aware of some gluteal lines. So here, we
can see a whole series of gluteal lines; anterior,
inferior, and posterior. Here, we can see
an anterior gluteal line. See that here. Here, we
can see inferior gluteal line running alongside
the body of the ilium. Here, we can see a
posterior gluteal line running alongside the
posterior iliac spines. So it’s the important
gluteal lines which you should be familiar
with as we look at the attachment sites later
on of the gluteal muscles. Now let’s turn
to the ischium. The ischium is most posteriorly
located, and it’s the postero-inferior aspect
of the hip bone, and also the acetabulum.
So here on this lateral surface where we can
see the acetabulum, if the ilium was superior
from this line here, then the ischium is coming
down into this region. So the ischium is everything
below this line we can see here. Again, it’s
uniting with the pubis and the ilium at the
acetabulum. We can see the body of the ischium
on this medial surface. So here, the organs
of the pelvis have been removed and we can
see a nice clear body of the ischium. Remember,
this connects the ilium and the pubis at the
acetabulum. We can see it’s on the acetabulus
surface here. We can also recognize the ramus
of the ischium, and the ramus of the ischium
is important. It connects the inferior pubic
ramus of the pubic bone. So here, if we look
at this lateral view, we can see running down
here from the body of the ischium, we have the
ramus of the ischium, and that runs towards
the inferior pubic ramus. Collectively, that
forms the ischiopubic ramus here. We can see
that on this lateral surface. We can also
see it coming down here on this medial surface,
and we can see it running down here on this
superior surface. It’s also going to form
the obturator foramen which we can see this
large space here. If we look at the ischium
in some bony landmarks, then some important
bony landmarks protruding posteriorly from
the ischium, we have two. We have the ischial
spine and the ischial tuberosity. Seen here
on the medial surface view, but projecting
posteriorly, we have the ischial spine superiorly
and the ischial tuberosity inferiorly. On
this lateral view, we can also see it.
So again here is anteriorly, and projecting posteriorly,
we have the ischial spine and we have the
ischial tuberosity. These bony landmarks are
important as they create the greater and lesser
sciatic notches. We can see here, we have
the greater sciatic notch running from the
posterior inferior iliac spine all the way
around to the ischial spine here, the greater
sciatic notch running around here. We then
have running from the ischial spine this little
concavity here, and that is the lesser sciatic
notch. Later on, we’ll see how these are
converted into foramina. But now let’s turn
to the pubis or the pubic bone. This is the
antero-lateral part of the hip bone, and the
more anterior part of the acetabulum.
So again, we can draw a kind of cross. Here we’ve
got the separation with the ilium above, and
then we come down here, and posteriorly, we
find the ischium. And then anteriorly just
here, we have the pubis. We have the pubic
bone. So just coming in this lower anterior
part of the acetabulum, all of this now becomes
the pubis. The body of the pubis connects
the left and right pubic bones at the pubic
symphysis. So if we look to this superior
surface, we can see the body of the pubis
here. And this is going to run along to the
other body of the pubis on the other pubic
bone. So these unites at the pubic symphysis.
And the pubic symphysis will be here. On this
superior view, you can see the body of the
pubis will go and it will connect to the body
of the pubis on the other side. We can see
this as well here on this medial surface passing
towards the symphyseal surface where the pubic
symphysis will be located. The pubis has two
rami. It has a superior which passes towards
the ischium, and has an inferior which passes
to the ischium as the ischiopubic ramus.
So here, we can see the superior pubic ramus
running in this direction, and here we can
see the inferior pubic ramus running in this
direction. Here, with the help of the ischium,
we can see the formation of the obturator
foramen where we have the superior pubic ramus
here, and we have the inferior pubic ramus here
forming this C part of the obturator foramen.
The ischium will then form this more posterior
aspect. If we look at some bony
landmarks on the pubis then antero-superior
border of the pubic body, so here, we find
the pubic crest. And here we find this pubic
crest located just here. Laterally on the
pubic crest we have the pubic tubercle. The
posterior margin of the superior pubic ramus
is known as the pecten pubis, and that is
running along in this direction. This is a
sharp raised edge that forms the pelvic brim.
So at some important bony landmarks, we have
the pubic crest. Apart the pubic crest, we
have the pubic tubercle. And then we have
the pecten pubis which forms the pelvic brim.
So, there’s a whole series of bony landmarks
on the hip bone. If we now look at the hip
bone itself, then we can see that we have
these greater and lesser sciatic foramina, and
these are converted into greater and lesser
sciatic notches via these two ligaments; the
sacrospinous and the sacrotuberous.
So we can see the sacrospinous is forming this greater
sciatic foramen and the sacrotuberous and
the sacrospinous are forming the lesser sciatic
foramen. We also, as I mentioned, have the
obturator foramen. It’s important to bear
in mind the hip in its anatomical position,
and that is tilted a lot more anteriorly than
people may expect. This means that the anterior
superior iliac spine and the anterior superior
aspect of the pubis are really in the same
coronal plane. It’s tilted a lot more forwards.
This means the internal surface of the pubis
here is facing superiorly, and the pelvic inlet
here is more vertical than it is horizontal.
So the hip bone is actually tilted more forwards.
Now let’s move on to the femur, the femur
which is the thigh bone within the thigh.
We can see here we have an anterior right
femur, and we have a posterior right femur.
Here we have the anterior view of the right
femur. We’ve got the head of the femur here.
It’s large, it’s spherical, and articulates
with the acetabulum at the hip joint. It contains
a depression medially, which is the fovea
here, and this contains the attachment site
for the ligaments of the head of the femur.
The neck joins the head to the shaft. So here
we can see the neck of the femur, and it contains
two trochanters, a greater and a lesser trochanter.
And these are clearly seen on the posterior
view. Running between the two trochanters on these
anterior aspects, we have the intertrochanteric
line. And that’s running between the two
trochanters on this anterior aspect.
If we look at the shaft, then it’s relatively
dull. It’s smooth. It’s rounded on the
anterior surface. Posteriorly, there are some
features we’ll mention. Distally though
on this anterior surface, we can see some
femoral condyles. We can also see passing
towards these condyles, the medial and lateral
epicondyles. And these again give rise to
those condyles which articulate with the tibial
condyles and form the knee joint. We can also
see a smooth region here, and that is the
patellar surface. If we look at the posterior
view now of the femur, we can still see we’ve
got our head, we’ve got our neck, and we
can see we’ve got a greater trochanter now,
and clearly, a lesser trochanter. But here,
we can see we now have an intertrochanteric
crest. We don’t have that line.
Looking at the shaft, we can see running down from
these trochanters, we have the lateral and
the medial lip that forms the linea aspera.
Superiorly, the lateral lip blends with the
roughened gluteal trochanter, and the medial lip
runs to the lesser trochanter as the pectineal line.
And we’ll see some important muscles
attached here like pectineus.
Inferiorly, the lateral and the medial lips, they separate
to form the lateral and medial supracondylar
lines. So distally, we can now clearly see
a large femoral condyle. We can still make
out the lateral epicondyle, and the medial
epicondyle would be on this side. On the medial
epicondyle, we can see an adductor tubercle
which is an important attachment. But the
femoral condyles, medial and lateral, they’re
separated by this intercondylar fossa which
we’ll soon appreciate, contain some cruciate
ligaments and it articulates with the tibial
condyles to form the knee joint. On the medial
condyle, we can see we’ve got the adductor
tubercle here, and that’s located on the
superomedial medial aspect of that medial
condyle. Now let’s have a look at the patella.
We can see the patella, this anterior and
posterior view. This is a right patella.
It’s a large sesamoid bone and it develops
intratendinously after birth. So it develops
as an ossification of the tendon within the
patellar tendon. It’s located anterior to
the distal femur. We’ve got the patellar
surface which we can see on the anterior surface
of the femur. It’s triangular in shape.
Its anterior surface is convex and has a broad
superior base. It has a lateral and medial
border, and these converge to form a pointed
inferior edge known as the apex. Posteriorly,
the articular surface is smooth and it’s
divided by vertical ridge, which allows it
to sit in the posterior in the patellar surface
of the distal femur. Now let’s have a look
at the tibia. Here, we can see we have anterior
and the posterior surfaces of the tibia.
We can see we’ve got a medial malleolus here.
And on the posterior surface, we can still
see the medial malleolus forming the ankle joints.
And we have a fibular surface. This is the
surface that you would see if you were standing
where the fibula was. We’ll talk, first
of all, about the tibial plateau, the proximal
part of the tibia. The tibia is larger than
the fibula and it’s mostly involved with weight
bearing. The articulations occur superiorly
between the femoral condyles on the tibial plateau
which we can see here, and also, inferiorly
with the talus. Here, I mentioned previously
the medial malleolus. When the fibula is in
place, we have two malleoli, medial and lateral,
and they help to form the ankle joint.
Proximally, we can see we have medial and
lateral condyles of the tibia. Here we have
a lateral condyle, and here we have a medial
condyle. We can see this anteriorly, and we
can also see this posteriorly. Here’s the
medial condyle and here’s the lateral condyle.
They are separated by the intercondylar eminence,
this small little elevation of bone that sits
on top of the tibial plateau and overlies
flat surface. Lateral and medial intercondylar
tubercles. So here, we can see some lateral
and medial intercondylar tubercles forming
this intercondylar eminence. As we’ll see,
these are important. The shaft of the tibia
is triangular in cross-section. The anterior
border we find, we have the tibial tuberosity,
and then we have this rather sharp anterior
edge. The lateral, medial, and posterior surfaces
form this triangular shape in cross-section.
Here, we have the medial surface running down
towards the medial malleolus, and here, we
can see the lateral surface forming the sharp
anterior border. If we will have the fibular
view, then we can see we have this lateral
surface here. The anterior edge is here, the anterior
border. And then we can see the posterior
surface where we have the nutrient foramen
for the nutrient artery to pass into the tibia.
We can also see on this posterior surface,
we have the soleal line, and this is important
as it’s the site of origin for the soleus
muscle. We can see running along the shaft,
we have the line for the interosseous border,
and that is where the interosseous membrane
connects the fibula to the tibia. Distally,
we have the narrowing of the tibia before
we have this medial expansion, which is the
medial malleolus, and we have laterally, the
fibular notch. And that allows for articulation
with the fibula. In the fibular view, we
can see we have this depression here. This
fibular notch that has this, the fibula.
Now let’s turn to the fibula. We can see the
fibula has a head and neck, and then it has
a thin shaft, and then dilates inferiorly
or distally to form the lateral malleolus.
Here we can see it’s slender. It’s positioned
posterolaterally to the tibia, and it’s
attached to the tibia via this interosseous
membrane. Proximally, we have an enlarged
head, and then we have a narrow neck. The
head articulates with the articular surface
on the lateral surface of the tibia. Here,
we can see an articular facet which allows
the head of the fibula to articulate with
the tibia. As we go down the shaft, we see
we have lateral and we have medial surfaces. We
have an interosseous border where the membrane,
the interosseous membrane will pass between
the two, and we also have this posterior border
which we can see here. Distally, we have a
lateral expansion, and this is the lateral
malleolus. Here we can see the malleolar fossa,
and here we can see the lateral malleolus here.
And this combined with the medial malleolus
forms the articulation with the talus of the
foot to form the ankle joint. Now let’s move
on to the foot and look at the numerous
bones that make up the foot, both the tarsals,
the metatarsals, and the phalanges.
We’ve got a whole series of pictures that show different
views of the foot. We can see that we have
tarsus, these seven bones that help to form the main body of the foot,
and then we can see we have the metatarsus
that contains these metatarsals, and then
we can see we have the phalanges.
But for the tarsus, we can have the calcaneus, the
talus, navicular, cuboid, and three cuneiforms.
Here, we can locate, if we look more superiorly,
the talus, and this is going to allow articulation
between the tibia and the fibula via the two
malleoli. Then inferior to the talus underneath,
we have the calcaneus. We can see the calcaneus
is then going to articulate with the cuboid,
we can see here. And directly in front of
the talus, we can see we have the navicular.
So we’ve got the talus here. We’ve got the
navicular. And then we move lateral and
we find the cuboid. We then have three cuneiforms
that are positioned anterior to the navicular bone.
We have the medial, the intermediate, and the
lateral. So we have the talus,
we have the calcaneus here, we have the navicular,
the cuboid, and then three cuneiforms - medial,
intermediate, and lateral. If we then look at
the metatarsus, here we have five metatarsals.
These connect to the phalanges, and toe 1
is the shortest metatarsus. So it’s not
as long as the 2, 3, 4, and 5. So the
phalanges had a similar arrangement as we
had in the hand. So toe 1 has two phalanges,
a proximal and a distal. And toe 2 to 5
has a proximal, a middle, and a distal. And this
is repeated from toes 2, 3, 4, and 5.
So let’s have a look at a bit more detail
at these tarsal bones. Let’s start off with
the calcaneus. We can see it’s the largest,
the strongest of the tarsal bone, and articulates
with the talus superiorly and the cuboid bone
anteriorly. We can see it here. We can see
if we have a plantar view here, a lateral
view and a dorsal view. This is the calcaneus.
Medially, if we look at this medial aspect
of the calcaneus, we see it forms what’s
known as the sustentaculum tali. And this
helps to support the talus. It’s like a
shelf and it helps to support the talus superiorly,
the sustentaculum tali. We’ll later on appreciate
some important tendons, blood vessels and
nerves pass underneath the sustentaculum tali
as they cross posteriorly to the medial malleolus
to the enter the sole of the foot.
We also have the calcaneal tuberosity. We can see
that here, this large inferior bulge, the
calcaneal tuberosity, and that’s an important
attachment site for the calcaneal tendon.
So now if we look at the talus, then that
sits superior to the calcaneus, and we have
a head, we have a neck, and we have a body.
So we can see the neck of the talus here in
this lateral view, and if we move on to the
medial view, we see most anteriorly, we have
the head, then we have the neck, and then
we can see we have posteriorly the body.
We can see how it’s passing down and attaching to
the calcaneus in line with the sustentaculum tali.
And here, we can see the talus. The trochlear
surface which we can see here, so
we have the trochlear surface similar to the
trochlear that we have in the upper limb,
allows for articulation with the two malleoli
coming from the tibia and the fibula.
And we’ll appreciate that this is wedge shaped
allowing for strengthening of the ankle joint
during various movements. Now let’s turn
to the navicular. This is a flattened boat
shaped bone. And it is located between the
talus posteriorly, and the three
cuneiforms anteriorly. We can see it here clearly in
this dorsal view. On the lateral view, we
can see it’s lying medial to the cubiod
bone, and on this medial view, we can see
it’s running against the medial surface of
the foot. On the inferior surface of the
navicular, we see a medially orientated tuberosity,
and these were important for muscle attachments.
If we then look at the cuboid bone, we can see the
cuboid is located in between the calcaneus,
and the fourth and fifth metatarsals. Medially,
we would have the lateral cuneiform bone.
So here we can see the cuboid. The cuboid
itself has a tuberosity which we can again
see on the plantar view, and we also see it
has a groove for the fibularis longus tendon.
We’d appreciate that when we look at the
fibula muscles in a later lecture. If we now
move to the cuneiforms, now these forms a row
of bones that is directly anterior to
the navicular. And we have from medial to lateral,
we have a medial, intermediate, and a lateral
cuneiform. We can see the three here in this
dorsal view, and we can see the three here
in this plantar view. All of these three bones
articulate with the navicular posteriorly
and the metatarsals anteriorly. So now let’s
talk about those metatarsals. We have five
metatarsals, and these run forward to connect
to the phalanges of the digits. Toe 1 has
the shortest metatarsal, and we can see that
here. It’s very large, it’s very substantial,
it’s made up of a base, it’s made up of
a shaft, and it’s made up of a head.
So we have this very broad large first metatarsal,
but it’s also the shortest. If we look at
metatarsals 2, 3, 4, and 5, we see they have
a base, a shaft, and a head, but these are
much thinner. We can then see just like the
digits in the hand, digit 1 has two phalanges,
a proximal and a distal. So we can see the
proximal and distal phalanges of the first
digit, the toe. And then digits 2, 3, 4, and
5 have both proximal, have all proximal, middle,
and distal phalanges. Now let’s look at some
of the movements that we have occurring
at the lower limb. Here we can see movements
that were occurring at the hip joints.
We have flexion and we have extension. We can
see the hip joint being flexed in this direction,
and then being extended as it’s returned to the
standing position, and then hyperextended
backwards in this direction. We can see we
have abduction and adduction possible.
We have abduction, the leg is moved away from
the midline, and we have adduction, we can
see it’s brought towards the midline. And
it’s actually possible of going across the
midline and across the other standing leg. Here
we can we have lateral
and medial rotation occurring where the leg
is turned inwards towards the body, lateral
rotation, and it’s also turned outwards away
from the body medial rotation.
We can see at the knee joint, we can continue to
have flexion and extension where we see the
knee is fully extended. Here, we can see it
goes straight on from the thigh, and we can
see it’s flexed when the heel is brought
towards the posterior surface of the thigh.
Again, we can see we have medial and lateral
rotation of the knee where the foot is turned
either inwards or is turned outwards, medial
and lateral rotation. If we look at the ankle
joints, we can see we have dorsiflexion where
your heel is on the floor and your toes are
lifted upwards. And we have plantar flexion
where your heel is lifted upwards and your
forefoot, your toes, are depressed onto the floor.
We can see we have inversion and eversion.
This is again occurring at the ankle joints.
With inversion, the big toe, your number 1
toe is lifted up and your little toe, digit
5, is remaining on the floor. And conversely
with eversion, you have your great toe, number
1, remaining on the floor, whereas, your little
toe, digit number 5, is lifted up inversion
and eversion. If we then look at the toes,
you’ll see because we have the interosseous
muscles which we’ll later on describe,
that the toes is possible to abduct and adduct these
individual digits. Along with this movement,
there’s also a flexion and extension so
you can dorsiflex and you can plantarflex your digits.
So in this lecture, we’ve looked
at the surface anatomy of the lower limb,
the inferior appendicular skeleton, we've looked
at the gluteal, thigh, leg, and foot regions.
And then we’ve looked at the osteology of
the lower limb. We’ve looked at the gluteal
region where we had the ischium, the pubis,
and the ilium of the hip bone. We looked at
the thigh with the femur, the leg and the
tibia, fibula. And then the foot looking at
the tarsals, metatarsals, and phalanges, and
looking at some bony landmarks on these bones.
And then to finish, we briefly looked at the
movement of the lower limb.