Description

In this video I break down the bones of the foot (tarsals, metatarsals, and phalanges), using clear visuals to help you understand their anatomy and articulation.

Tarsal Bones

Talus (Talus): forms the ankle joint; features include trochlea, medial and lateral malleolar facets, and superior facet

Trochlea of talus (Trochlea tali): saddle-shaped top surface that articulates with tibia and fibula
Lateral process (Processus lateralis tali): attachment for lateral talocalcaneal ligament
Posterior calcaneal articular facet (Facies articularis calcanea posterior): articulates with calcaneus
Posterior process (Processus posterior tali): contains lateral and medial tubercles
Groove for flexor hallucis longus (Sulcus tendinis musculi flexoris hallucis longi): transmits flexor hallucis longus tendon
Sulcus tali (Sulcus tali): groove between articulating facets; forms sinus tarsi with calcaneal sulcus
Middle calcaneal articular facet (Facies articularis calcanea media): articulates with calcaneus
Anterior calcaneal articular facet (Facies articularis calcanea anterior): anterior articulation with calcaneus
Navicular articular surface (Facies articularis navicularis): forms talonavicular joint

Calcaneus (Calcaneus): heel bone; largest tarsal bone

Calcaneal tuberosity (Tuber calcanei): insertion for Achilles tendon and plantar aponeurosis
Medial and lateral processes (Processus medialis et lateralis tuberis calcanei): muscle origins including abductor digiti minimi, abductor hallucis
Sustentaculum tali (Sustentaculum tali): supports talus head; attachment for ligaments
Groove for flexor hallucis longus (Sulcus tendinis musculi flexoris hallucis longi): passes under sustentaculum
Calcaneal tubercle (Tuberculum calcanei): supports long plantar ligament
Fibular trochlea (Trochlea fibularis): guides fibularis tendons
Anterior, middle, and posterior talar articular surfaces (Facies articulares talares): articulate with talus
Cuboid articular surface (Facies articularis cuboidea): anterior surface for cuboid
Calcaneal sulcus (Sulcus calcanei): forms sinus tarsi with sulcus tali

Navicular (Os naviculare): located between talus and cuneiforms

Tuberosity of navicular (Tuberositas ossis navicularis): insertion for tibialis posterior

Cuboid (Os cuboideum): lateral bone between calcaneus and metatarsals

Tuberosity of cuboid (Tuberositas ossis cuboidei): attachment for ligaments
Groove for fibularis longus (Sulcus musculi fibularis longi): guides fibularis longus tendon
Calcaneal process (Processus calcaneus ossis cuboidei): supports cuboid-calcaneus articulation

Medial cuneiform (Os cuneiforme mediale): articulates with 1st metatarsal
Intermediate cuneiform (Os cuneiforme intermedium): articulates with 2nd metatarsal
Lateral cuneiform (Os cuneiforme laterale): articulates with 3rd metatarsal

Metatarsals

Metatarsals I–V (Ossa metatarsalia I–V): numbered medial to lateral; each has base, shaft, and head
Tuberosity of 1st metatarsal (Tuberositas ossis metatarsalis primi): insertion for fibularis longus
Tuberosity of 5th metatarsal (Tuberositas ossis metatarsalis quinti): insertion for fibularis brevis

Phalanges

Proximal phalanges (Phalanges proximales): 5 in total; base, shaft, and head
Middle phalanges (Phalanges mediae): 4 total; absent in big toe
Distal phalanges (Phalanges distales): 5 total; each ends with a tuberosity
Tuberosity of distal phalanx (Tuberositas phalangis distalis): attachment site for soft tissue

Mnemonic

“Tiger Cubs Need MILC”: Talus, Calcaneus, Navicular, Medial, Intermediate, Lateral cuneiforms, Cuboid

Sources:

Kozlowski, T. (2017). Memorix Anatomy, 2nd ed.

• Standring, S. (2020). Gray’s Anatomy, 42nd ed.
• Tubbs RS, Shoja MM, Loukas M. (2016). Bergman’s Encyclopedia of Human Anatomic Variation
• White TD, Folkens PA. (2005). The Human Bone Manual

Programs used: Complete Anatomy, Biorender, PowerPoint

Transcript

0:00:00.160,0:00:05.920
This is your foot. Well… the bones of it.
There are 26 bones in the foot, 7 tarsal

0:00:05.920,0:00:10.800
bones, 5 metatarsals, and 14 phalanges.
So what we’re going to do in this video

0:00:10.800,0:00:16.000
is to go through all the bones that make up the
tarsus, the metatarsal bones, and the phalanges.

0:00:16.000,0:00:19.120
What’s up everyone, my name is Taim. I’m a
medical doctor, and I make animated medical

0:00:19.120,0:00:22.960
lectures to make different topics in medicine
visually easier to understand. If you’d like a

0:00:22.960,0:00:26.880
PDF version or a quiz of this presentation, you
can find it on my website, along with organized

0:00:26.880,0:00:30.080
video lectures to help with your studies.
Alright, let’s get started.

0:00:30.080,0:00:34.000
The tarsal bones, those are the ones at
the back of the foot, basically forming

0:00:34.000,0:00:39.680
the ankle and the rearfoot. There are 7 of them
in total, and we’ll go through each one by one.

0:00:39.680,0:00:42.640
Let’s start with this bone
here, this is the talus.

0:00:42.640,0:00:47.600
Now, the most recognizable part of the talus
is this saddle-shaped structure on top called

0:00:47.600,0:00:52.960
the trochlea of the talus. This is the part
that sits right under the tibia and fibula.

0:00:52.960,0:00:57.120
If we look at this from the anterior view,
you’ll notice the trochlea is actually

0:00:57.120,0:01:03.040
divided into three distinct articular surfaces.
This one here is the medial malleolar facet, which

0:01:03.040,0:01:07.920
connects with the medial malleolus of the tibia.
On the other side we can see the lateral

0:01:07.920,0:01:12.960
malleolar facet for the fibula.
And superiorly is the superior facet,

0:01:12.960,0:01:17.600
that’s the part that directly articulates
with the inferior surface of the tibia.

0:01:17.600,0:01:23.600
These three surfaces together – superior, lateral,
and medial, are what make up the trochlear surface

0:01:23.600,0:01:28.960
of the talus. And what they do is, they form
the ankle joint, or the talocrural joint,

0:01:28.960,0:01:33.200
as you see here. We will go over this joint
visually in the next video, but for now,

0:01:33.200,0:01:38.400
let’s keep moving through the bony structures.
And to do that, we need to remove the tibia and

0:01:38.400,0:01:43.920
fibula, and then rotate the foot this way, we
now see a lateral view of the foot, so let’s

0:01:43.920,0:01:49.680
focus on the other structures of the talus now.
Since the talus is so large and shaped the way it

0:01:49.680,0:01:54.880
is, we can generally be divided into three
parts – the body, the neck, and the head.

0:01:54.880,0:01:58.960
On the body of Talus, you’ll find the
trochlea on top which we just talked about.

0:01:58.960,0:02:03.600
But there are some other important things here.
On the lateral side, there’s this small bony

0:02:03.600,0:02:09.120
projection called the lateral process. This is
where the lateral talocalcaneal ligament attaches,

0:02:09.120,0:02:13.200
helping to stabilize the connection between
the talus and the calcaneus underneath.

0:02:13.200,0:02:19.520
Another thing, you see this area here in purple?
This is called the posterior calcaneal articular

0:02:19.520,0:02:24.400
facet. This surface connects directly with
the calcaneus below, and it’s one of three

0:02:24.400,0:02:29.760
surfaces involved in the subtalar joint.
Over on the other side, we have the

0:02:29.760,0:02:34.160
posterior process. So let’s rotate the
bone so we can get a better view of it.

0:02:34.160,0:02:40.000
The posterior process splits into two tubercles:
a lateral tubercle, which is where the posterior

0:02:40.000,0:02:44.800
talofibular ligament attaches, and a medial
tubercle, which serves as the attachment

0:02:44.800,0:02:50.960
site for the medial talocalcaneal ligament.
And right in between them is this groove here—the

0:02:50.960,0:02:56.160
groove for the tendon of flexor hallucis
longus. It runs between the two tubercles,

0:02:56.160,0:03:00.160
and as you can see here, it transmits
the flexor hallucis longus tendon,

0:03:00.160,0:03:04.880
which continues forward toward the big toe.
Okay, so now what I want to do is go ahead

0:03:04.880,0:03:10.000
and isolate this bone, tilt it so
we see underneath, and then zoom in.

0:03:10.000,0:03:13.120
What structures can we find
on the neck of the talus?

0:03:13.120,0:03:18.000
This groove here is called the sulcus tali,
a deep groove between the posterior facet

0:03:18.000,0:03:22.080
and the anterior part of the bone. It’s
also important because it accommodates

0:03:22.080,0:03:28.000
the interosseous talocalcaneal ligament.
Next to it we can see the middle calcaneal

0:03:28.000,0:03:32.480
articular facet, this is the second of the
three articulating surfaces that connect the

0:03:32.480,0:03:36.000
talus with the calcaneus.
Now let’s move anteriorly

0:03:36.000,0:03:40.480
to the head of the talus.
The most obvious surface here is this large

0:03:40.480,0:03:45.920
navicular articular surface, which connects with
the navicular bone, it’s part of the talonavicular

0:03:45.920,0:03:51.680
joint, a very mobile joint in the midfoot.
Right beside that, we can also see the anterior

0:03:51.680,0:03:57.120
calcaneal articular surface, this is the third and
final surface that connects with the calcaneus.

0:03:57.120,0:04:02.160
So that was all I had for the talus.
Now let’s move on to this large bone

0:04:02.160,0:04:06.960
underneath it, this is the calcaneus.
The calcaneus articulates with the talus

0:04:06.960,0:04:11.920
above it, and with the cuboid bone in front.
The first noticeable structure we can see on

0:04:11.920,0:04:17.360
this bone is this large, roughened area back
here—this is the calcaneal tuberosity. It’s

0:04:17.360,0:04:22.000
super important. As you can see here,
it forms the actual heel of your foot.

0:04:22.000,0:04:26.560
It also serves as the attachment point for
the plantar aponeurosis, which is a thick band

0:04:26.560,0:04:31.280
of connective tissue that runs from the heel
all the way to the heads of the metatarsals,

0:04:31.280,0:04:36.320
helping to support the arch of the foot.
Also attached here is the calcaneal tendon,

0:04:36.320,0:04:41.840
or Achilles tendon, which is essentially the
shared tendon of the triceps surae muscle group,

0:04:41.840,0:04:45.600
made up of the gastrocnemius and
soleus, as you see here. Also the

0:04:45.600,0:04:51.200
plantaris muscle should often insert here as well.
Now, if we go back to this view again and look at

0:04:51.200,0:04:56.960
the calcaneus from this side, we’ll notice that
the tuberosity has two projections—these are the

0:04:56.960,0:05:01.280
medial processes and lateral processes.
The lateral process provides origin

0:05:01.280,0:05:05.360
for abductor digiti minimi,.
The medial process serves as the

0:05:05.360,0:05:12.160
origin for flexor digitorum brevis and abductor
hallucis, and it also supports flexor retinaculum

0:05:12.160,0:05:17.680
Another structure we can see is the sustentaculum
tali, as you see here. This one’s interesting,

0:05:17.680,0:05:23.600
it projects medially like a little shelf, and what
it does is support the head of the talus which is

0:05:23.600,0:05:29.280
right above it. And it also gives attachment to
some important ligaments, like the tibiocalcaneal

0:05:29.280,0:05:34.720
ligament, the plantar calcaneonavicular ligament,
which you might know as the spring ligament, and

0:05:34.720,0:05:41.040
the medial talocalcaneal ligament. And if you look
just beneath it, you’ll notice this groove here.

0:05:41.040,0:05:45.680
That’s the groove for the tendon of flexor
hallucis longus, which passes right under the

0:05:45.680,0:05:50.960
sustentaculum and continues toward the big toe.
Another thing we can see is the calcaneal

0:05:50.960,0:05:56.480
tubercle, which sits more inferiorly. It provides
attachment to the long plantar ligament and helps

0:05:56.480,0:06:01.120
support the lateral arch of the foot.
If we now rotate the calcaneus and look

0:06:01.120,0:06:05.760
from this lateral view, we can also see this
small bump here, this is the fibular trochlea.

0:06:05.760,0:06:10.560
It acts kind of like a pulley, guiding the
tendons of fibularis longus and brevis as they

0:06:10.560,0:06:16.320
course around the lateral side of the foot.
Okay. Now what I want to do is isolate the

0:06:16.320,0:06:22.880
calcaneus, rotate it this direction, and we’ll
get this superior medial view. So let’s zoom in.

0:06:22.880,0:06:28.640
From this angle, we can see a few joint surfaces
clearly. Here’s the anterior talar articular

0:06:28.640,0:06:33.280
surface, which connects with the head of the
talus. Just behind that is the middle talar

0:06:33.280,0:06:39.280
articular surface, and then further back is the
posterior talar articular surface, the largest

0:06:39.280,0:06:45.840
one, forming most of the subtalar joint. Over
here, this flattened area is the articular surface

0:06:45.840,0:06:51.600
for the cuboid. And this groove running between
the talar facets, that’s the calcaneal sulcus.

0:06:51.600,0:06:57.600
Together with the sulcus tali, it forms the sinus
tarsi, which we’ll cover when we get into joints.

0:06:57.600,0:07:02.400
So that was all I had for the calcaneus.
Let’s now go to the navicular bone.

0:07:02.400,0:07:08.160
The navicular bone is interesting, it lies just
anterior to the talus, behind the three cuneiform

0:07:08.160,0:07:13.920
bones: the medial, intermediate, and lateral. And
just lateral to it, we find the cuboid. What we

0:07:13.920,0:07:19.920
can see clearly on this bone is this bump right
here—this is the tuberosity of the navicular bone.

0:07:19.920,0:07:24.400
It serves as the insertion point for
the tibialis posterior tendon. And it

0:07:24.400,0:07:29.200
also provides attachment to the tibionavicular
ligament, which is part of the deltoid ligament

0:07:29.200,0:07:35.200
complex, and the plantar calcaneonavicular
ligament, also known as the spring ligament.

0:07:35.200,0:07:38.800
So that was the navicular.
Let’s now move on to the cuboid.

0:07:38.800,0:07:43.680
The cuboid lies in front of the calcaneus,
laterally next to the navicular and the lateral

0:07:43.680,0:07:50.160
cuneiform. And anteriorly, it articulates with the
fourth and fifth metatarsals. If we now rotate the

0:07:50.160,0:07:55.280
foot to look from underneath, this is the plantar
view, and here we can see two structures. First

0:07:55.280,0:08:01.200
is this, this is the tuberosity of the cuboid,
and the other one is the calcaneal process. The

0:08:01.200,0:08:06.800
tuberosity here serves as the attachment site for
the plantar calcaneocuboid ligament. And running

0:08:06.800,0:08:12.560
through it, we have this curved groove, the groove
for the tendon of fibularis longus. The tendon

0:08:12.560,0:08:18.080
loops through this groove and crosses the sole
obliquely toward the base of the first metatarsal.

0:08:18.720,0:08:24.400
Alright. That’s the cuboid. Now let’s
move on to the three cuneiform bones.

0:08:24.400,0:08:29.840
There’s the medial cuneiform, the intermediate
cuneiform, and the lateral cuneiform. So why are

0:08:29.840,0:08:34.560
they named like this? It’s simply based on their
position. The medial cuneiform lies on the inner

0:08:34.560,0:08:39.200
side of the foot, the intermediate sits right in
the middle. And the lateral cuneiform is on the

0:08:39.200,0:08:44.880
lateral side. These three bones lie between the
navicular posteriorly and the bases of the first,

0:08:44.880,0:08:50.000
second, and third metatarsals anteriorly.
They’re wedge-shaped bones that contribute

0:08:50.000,0:08:54.560
to the transverse arch of the foot.
So, that was all the tarsal bones. And

0:08:54.560,0:09:00.480
to remember them, here’s a helpful mnemonic:
“Tiger Cubs Need MILC.” Talus, Calcaneus,

0:09:00.480,0:09:06.400
Navicular, Medial cuneiform, Intermediate
cuneiform, Lateral cuneiform, and Cuboid.

0:09:06.400,0:09:10.320
Alright. Awesome.
Now let’s move further down the foot. What

0:09:10.320,0:09:16.000
we see next are the metatarsals and the phalanges.
The metatarsals form the midfoot, you can think

0:09:16.000,0:09:21.200
of them as the foot’s version of the palm in
your hand. And the phalanges make up the toes.

0:09:21.200,0:09:25.440
As you can see here, we’ve got five
metatarsal bones, and just like in

0:09:25.440,0:09:30.560
the hand, they’re numbered 1 through 5.
Number 1 is on the side of the big toe,

0:09:30.560,0:09:36.640
and number 5 is on the side of the little toe.
Each metatarsal has a base, a head, and a shaft.

0:09:36.640,0:09:41.360
The base is the proximal part that articulates
with the tarsal bones. The shaft is the long

0:09:41.360,0:09:46.720
middle portion. And the head is the rounded distal
end that connects with the proximal phalanges.

0:09:46.720,0:09:50.400
What’s special about the base though is
that, if you look at the inferior surface

0:09:50.400,0:09:56.240
of the metatarsals, you’ll notice two distinct
features. One is this—this is the tuberosity

0:09:56.240,0:10:01.600
of the first metatarsal, and this serves as the
attachment for the fibularis longus tendon. And

0:10:01.600,0:10:05.680
on the other side, we’ve got the tuberosity
of the fifth metatarsal, and this is where

0:10:05.680,0:10:10.880
the fibularis brevis muscle inserts.
So that was the metatarsals. Now let’s

0:10:10.880,0:10:13.760
focus on the phalanges.
There are three rows of

0:10:13.760,0:10:17.920
phalanges. We’ve got the proximal phalanx,
the middle phalanx, and the distal phalanx.

0:10:17.920,0:10:25.120
So let’s count them. For the proximal phalanx,
we’ve got 1, 2, 3, 4, and 5, one on each toe.

0:10:25.120,0:10:30.880
The middle phalanx only starts from the
second toe, so we’ve got four: 1, 2, 3, and 4.

0:10:30.880,0:10:36.240
And then for the distal phalanx, again
we’ve got five, 1, 2, 3, 4, and 5.

0:10:36.240,0:10:41.600
So the big toe only has a proximal and a distal
phalanx—no middle phalanx. Just like the thumb.

0:10:41.600,0:10:44.400
And here, you can see them on the
foot—it just helps to visualize

0:10:44.400,0:10:49.120
their positions and how they’re arranged.
Each proximal phalanx also has a base, a shaft,

0:10:49.120,0:10:54.400
and a head—same structure as the metatarsals.
The middle phalanges follow that same pattern.

0:10:54.400,0:10:58.640
But if you look at the distal phalanges, it’s
slightly different. We’ve still got the base

0:10:58.640,0:11:04.400
and shaft, but instead of a typical head, we
have this expanded area at the end, this is the

0:11:04.400,0:11:09.840
tuberosity of the distal phalanx, which functions
like the head and gives attachment to soft tissue.

0:11:09.840,0:11:14.160
And with that—we’ve covered the tarsal
bones, the metatarsals, and the phalanges.

0:11:14.160,0:11:18.160
Those are all the bones of the foot.
In the next video, we’re going to look at

0:11:18.160,0:11:22.480
all the joints of the foot—how they connect,
and how they move. Click the next video to

0:11:22.480,0:11:25.920
continue learning, and I’ll see you there.
If you want a handmade PDF version of this

0:11:25.920,0:11:29.840
lecture, take a quiz to test your knowledge,
or access an organized list of all my videos,

0:11:29.840,0:11:32.800
you can find everything on my website.
Thanks for watching! See you in the next one.