Description

In this video I break down the anatomy of all the major joints in the foot and ankle, covering ligaments, arches, and common conditions like flat foot and high arches, all explained visually.

Ankle Joint (Talocrural Joint – Articulatio talocruralis)

Medial malleolar facet (Facies malleolaris medialis): talus–tibia articulation
Lateral malleolar facet (Facies malleolaris lateralis): talus–fibula articulation
Superior facet (Facies superior): talus–tibia weight-bearing surface
Joint capsule (Capsula articularis): fibrous enclosure maintaining synovial cavity
Deltoid ligament (Ligamentum collaterale mediale): includes anterior tibio‑talar, tibionavicular, tibiocalcaneal, posterior tibio‑talar ligaments; resists eversion
Lateral collateral ligament (Ligamentum collaterale laterale): includes anterior/posterior talofibular and calcaneofibular ligaments; resists inversion

Subtalar Joint (Articulatio subtalaris)

Lateral talocalcaneal ligament (Lig. talocalcaneum laterale)
Posterior talocalcaneal ligament (Lig. talocalcaneum posterius)
Interosseous talocalcaneal ligament (Lig. talocalcaneum interosseum)
Medial talocalcaneal ligament (Lig. talocalcaneum mediale)

Talonavicular Complex (Articulatio talocalcaneonavicularis)

Talonavicular ligament (Lig. talonaviculare)
Spring ligament (Lig. calcaneonaviculare plantare)

Calcaneocuboid Joint (Articulatio calcaneocuboidea)

Bifurcate ligament (Lig. bifurcatum)
Dorsal calcaneocuboid ligament (Lig. calcaneocuboideum dorsale)
Plantar calcaneocuboid ligament (Lig. calcaneocuboideum plantare)
Long plantar ligament (Lig. plantare longum)

Transverse Tarsal Joint (Articulatio tarsi transversa)

Functional line across talonavicular and calcaneocuboid joints allowing forefoot rotation

Cuneonavicular Joint (Articulatio cuneonavicularis)

Dorsal cuneonavicular ligaments (Lig. cuneonaviculare dorsalia): stabilizes dorsal midfoot
Plantar cuneonavicular ligaments (Lig. cuneonaviculare plantaria): reinforces plantar connection

Cuneocuboid Joint (Articulatio cuneocuboidea)

Dorsal cuneocuboid ligament (Lig. cuneocuboideum dorsale)
Plantar cuneocuboid ligament (Lig. cuneocuboideum plantare)
Interosseous cuneocuboid ligament (Lig. cuneocuboideum interosseum)

Intercuneiform Joints (Articulationes intercuneiformes)

Dorsal/Plantar/interosseous intercuneiform ligaments: maintain integrity among adjacent cuneiform bones

Tarsometatarsal Joints (Articulationes tarsometatarsales)

Dorsal tarsometatarsal ligaments: reinforce joint dorsally
Plantar tarsometatarsal ligaments: strengthen plantar side
Cuneometatarsal interosseous ligaments: provide deep midfoot stability

Intermetatarsal Joints (Articulationes intermetatarsales)

Dorsal/Plantar/interosseous metatarsal ligaments: anchor between metatarsal bases
Lisfranc joint complex: includes tarsometatarsal and intermetatarsal joints; key to midfoot stability

Metatarsophalangeal Joints (Articulationes metatarsophalangeae)

Collateral metatarsophalangeal ligaments (Lig. collateralia): lateral support at joint
Plantar ligaments (Lig. plantares): reinforce plantar capsule
Deep transverse metatarsal ligament: binds metatarsal heads

Interphalangeal Joints (Articulationes interphalangeae)

Collateral (Lig. collateralia) and plantar ligaments (Lig. plantares): stabilize toe joints

Arches of the Foot

Medial longitudinal arch: supported by spring ligament, long and short plantar ligaments, tibialis posterior, flexor hallucis longus
Lateral longitudinal arch: flatter and weight-bearing
Transverse arch: spans midfoot; maintained by tibialis anterior, fibularis longus

Common Conditions & Clinical Notes

Pes planus (Flatfoot): collapsed medial arch causes strain, postural issues, gait changes
Pes cavus (High arch): reduced shock absorption, forefoot/heel pressure, instability
Lisfranc injury: damage to ligaments between tarsals/metatarsals; critical midfoot instability

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

Programs used: Complete Anatomy, Biorender, PowerPoint

Transcript

0:00:00.080,0:00:04.320
In the last video, we looked at all the bones
in the foot. But bones on their own would

0:00:04.320,0:00:09.280
just fall apart. So how does your foot stay
connected, and absorb impact when you walk?

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It all comes down to this, the joints.
In this video, we’re going to go through

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all the major joints of the foot. So we’ll
cover the ankle joint, the subtalar joint, the

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talocalcaneonavicular joint, the calcaneocuboid
joint, the cuneonavicular joint, the cuneocuboid

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joint, and the intercuneiform joints. Then
we’ll move on to the tarsometatarsal joints,

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intermetatarsal joints, metatarsophalangeal
joints, and finally the interphalangeal joints.

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It sounds like a lot—but trust me, it’ll
all make sense by the end of the video.

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We’re also going to talk about the arches
of the foot, why they’re built like that,

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and a few common issues – like flat foot.
What’s up everyone, my name is Taim. I’m

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a medical doctor, and I make animated medical
lectures to make different topics in medicine

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visually easier to understand. If you’d like a PDF
version or a quiz of this presentation, you can

0:00:55.520,0:00:59.040
find it on my website, along with organized
video lectures to help with your studies.

0:00:59.040,0:01:02.720
Alright, let’s get started.
In the previous video on the Tibia and the Fibula,

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we covered the interosseous membrane and the
distal tibiofibular joint. We have followed

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the joints down to this point. The next joint
after that is the talocrural joint, or simply,

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the ankle joint. Makes sense?
Let’s start here.

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This is an articulation between three bones.
As you can see here, what we’re looking at is

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the talus down here, the distal end of the tibia,
and the lateral malleolus of the fibula. Together,

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these form the ankle joint through a
specific set of articulating surfaces.

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First, we have the medial malleolar
facet on the talus. This part articulates

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with the articular facet of the medial
malleolus of the tibia, so right here.

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This is the lateral malleolar facet on the talus.
And it connects with the articular facet of the

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lateral malleolus of the fibula, so like this.
And then in the middle we got the superior facet,

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which meets the inferior articular surface of the
tibia, we can’t really see it from this view, but

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it’s on the inferior side of Tibia, so like this.
Now, we already covered all of these bony surfaces

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in the video about the bones of the foot, so
I’m going to assume you’re familiar with the

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talus and the rest of the bones. If you’re not,
I highly recommend going back and watching the

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video on the bones of the foot first, it’ll
make this video a whole lot easier to follow.

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Alright, now let’s reassemble them.
Surrounding the whole joint is this,

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its capsule. It’s a capsule that’s attached
to the borders of the articular surfaces, and

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it helps to enclose and protect the joint space.
But the capsule alone isn’t enough for stability,

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so the joint is reinforced
by a set of strong ligaments.

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Let’s go through them,
starting with the medial side.

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On this side we’ve got four ligaments. Anterior
tibiotalar ligament, tibionavicular ligament,

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going down to the navicular bone. We’ve got
the tibiocalcaneal ligament, anchoring to the

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calcaneus. And the posterior tibiotalar ligament,
running from the back of the tibia to the talus.

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These four together form what’s commonly referred
to as the medial collateral ligament of the ankle,

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or simply the deltoid ligament. It’s a very
strong, triangular-shaped ligament that

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prevents excessive eversion, so it stops
the ankle from rolling too far inward.

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Now let’s look at the lateral side.
Here, we’ve got three ligaments. The

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anterior talofibular ligament in front, the
posterior talofibular ligament at the back,

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and in between them, running downward,
the calcaneofibular ligament.

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These three together make up the lateral
collateral ligament of the ankle. Compared

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to the deltoid ligament, these are thinner
and more prone to injury, especially the

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anterior talofibular ligament, which is the one
most commonly torn in a typical ankle sprain.

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So that’s the structure of the ankle joint.
Functionally, it primarily allows for

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dorsiflexion, which is pulling the foot upwards,
and it does plantarflexion, which is pointing the

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foot down. In addition to this, it does also allow
for a small amount of inversion and eversion,

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but most of those movements actually come from the
joints just below it, which we’ll talk about next.

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The next joint is called the
subtalar joint, so as the name says,

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it’s the joint just below the talus.
It’s an articulation between the

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posterior talar articular surface and
the posterior calcaneal articular facet.

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They’re enclosed by a capsule which wraps around
just these posterior surfaces, and it helps

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seal the joint and hold synovial fluid inside.
But of course, just like we saw in the ankle,

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it’s the ligaments that give
the joint its real stability.

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And these are the lateral talocalcaneal
ligament, running across the lateral side.

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Posterior talocalcaneal ligament, which goes
across the back. And deep between the two bones,

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anchoring them together, is the talocalcaneal
interosseous ligament. This one sits in the

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tarsal sinus, right between the talus and
calcaneus, it’s a super strong stabilizer.

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In addition to those, on the medial side,
there’s the medial talocalcaneal ligament.

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So that was the subtalar joint.
Now let’s move on to the next one,

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which lies between the talus, calcaneus,
and navicular. This joint right here.

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It’s called the talocalcaneonavicular joint,
and it’s actually functionally connected to the

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subtalar joint we just covered, they work together
to allow inversion and eversion of the foot.

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This one’s a bit more complex because of the way
all three bones interact at the front of the foot.

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It’s held in place by two major ligaments.
First is the talonavicular ligament,

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stretching from the head of the talus
to the navicular. And below that,

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we’ve got the plantar calcaneonavicular ligament,
also known as the spring ligament. This one

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supports the head of the talus from below and
plays a huge role in maintaining the medial

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longitudinal arch of the foot, which we’ll
talk about more a little later in this video.

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So, that’s these two joints.
Here’s the calcaneus, and here’s cuboid. The

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joint between them is the calcaneocuboid joint.
And this joint is stabilized by three ligaments.

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The bifurcate ligament, which actually
splits into two branches and attaches to

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both the navicular and the cuboid. Then we’ve
got the dorsal calcaneocuboid ligament on top,

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and on the underside of the foot, we have this
huge ligament called long plantar ligament.

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Now, there’s actually a joint line that passes
through both the talocalcaneonavicular joint and

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the calcaneocuboid joint. This is what
we call the transverse tarsal joint.

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It’s not a separate anatomical joint, but
it is functionally and clinically important,

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because this joint line allows the forefoot to
rotate in relation to the hindfoot, it contributes

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to pronation and supination of the foot. And
that’s why it’s also used during amputations and

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surgeries, because it creates a clean separation
between the front and back parts of the foot.

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Alright, next,
Here we see the navicular. And here’s

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the cuneiforms, the medial, intermediate, and
lateral. Between them is the cuneonavicular joint.

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This joint is also held together by
a set of ligaments. On the top side,

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we have the dorsal cuneonavicular
ligaments, and underneath, we’ve got

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the plantar cuneonavicular ligaments, anchoring
the navicular to each of the cuneiform bones.

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Let’s keep going.
Here’s the cuboid, here’s the lateral cuneiform.

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Between them is the cuneocuboid joint.
This one is held in place by the dorsal

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cuneocuboid ligament on the dorsal side. And if we
look from the plantar view, we can see two more:

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the plantar cuneocuboid ligament, and
deep between the bones, the cuneocuboid

0:07:20.720,0:07:26.960
interosseous ligament. These help lock the joint
and add structural support to the lateral arch.

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Now, here we’ve got the three cuneiform
bones. The medial, intermediate, and lateral.

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Between them are the intercuneiform joints. Makes
sense? Just joints between adjacent cuneiforms.

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They are stabilized by three sets of ligaments.
On top, we’ve got the dorsal

0:07:42.160,0:07:45.440
intercuneiform ligaments.
On the plantar side, there are

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the plantar intercuneiform ligaments.
And in between the bones, we have the

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intercuneiform interosseous ligaments.
So, we’ve now covered all the joints

0:07:55.040,0:07:57.920
up until this point.
Makes sense so far?

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The joints after this is a joint between
the cuneiform bones and the cuboid,

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to the metatarsals. This set of joints
are called the tarsometatarsal joints.

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Each metatarsal connects with a specific
tarsal bone through one of these joints.

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And they’re held together dorsally by
the dorsal tarsometatarsal ligaments.

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From the plantar view, we’ve got the plantar
tarsometatarsal ligaments, and deeper inside,

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we have the cuneometatarsal interosseous
ligaments – which anchor the bases of the

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metatarsals to the cuneiform bones
and provide deep structural support.

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The next joints actually lie between the adjacent
bases of the 1st to 5th metatarsal bones.

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These are called the intermetatarsal joints.
They’re held together dorsally by the dorsal

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metatarsal ligaments, and in between the bones
we have the metatarsal interosseous ligaments.

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If we just flip to the plantar view, we can
also see the plantar metatarsal ligaments.

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Now just a quick note, this whole region,
from the tarsometatarsal joints to these

0:08:57.280,0:09:02.720
intermetatarsal joints, forms what’s called the
Lisfranc joint complex. It’s clinically important

0:09:02.720,0:09:08.640
because injuries here – called Lisfranc injuries,
can disrupt the stability of the entire midfoot.

0:09:08.640,0:09:12.800
Next up, here are the metatarsals,
and here are the proximal phalanges.

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The joints between them are called
the metatarsophalangeal joints.

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These joints are held in place by the collateral
metatarsophalangeal ligaments, and also the deep

0:09:22.480,0:09:27.760
transverse metatarsal ligament, which runs across
and links all the metatarsal heads together.

0:09:27.760,0:09:33.040
We can also see the articular capsule surrounding
each joint. From the plantar side, we can see the

0:09:33.040,0:09:38.640
plantar metatarsophalangeal ligaments, which
reinforce the underside of these joints.

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Now do you remember that each toe has a proximal
phalanx, a middle phalanx, and a distal phalanx,

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except the big toe, which only has two?
Between the proximal and middle phalanges,

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we have the proximal interphalangeal joints,
and between the middle and distal phalanges,

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we have the distal interphalangeal joints.
For the big toe, since there’s no middle phalanx,

0:09:59.920,0:10:03.360
it’s just one joint—called
the interphalangeal joint.

0:10:03.360,0:10:08.960
All of these are supported by two main
ligaments: the plantar interphalangeal ligaments,

0:10:08.960,0:10:14.960
and the collateral interphalangeal ligaments.
So that was everything on the joints of the foot.

0:10:14.960,0:10:18.560
Now, let’s talk about something
interesting—the arches of the foot.

0:10:18.560,0:10:24.640
We have three main arches. The medial longitudinal
arch, the lateral longitudinal arch, and the

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transverse arch which runs across the foot.
And here on the medial and lateral view,

0:10:29.440,0:10:34.320
we can see how these longitudinal arches are
naturally held. The lateral side is flat,

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which takes the majority of weight, and the
medial side is slightly bent. This arch is

0:10:39.760,0:10:45.040
actually supported by several structures. First,
there’s the plantar aponeurosis, a thick fibrous

0:10:45.040,0:10:50.080
sheet that spans from the heel to the toes,
helping maintain the shape of the arch. Then

0:10:50.080,0:10:54.560
there are the plantar ligaments—especially the
long plantar ligament, the short plantar ligament,

0:10:54.560,0:10:59.760
and the plantar calcaneonavicular ligament,
which you might also know as the spring ligament.

0:10:59.760,0:11:05.600
And we got muscles that reinforce this arch, like
the tibialis posterior, tibialis anterior, flexor

0:11:05.600,0:11:10.960
hallucis longus, and both flexor digitorum longus
and brevis. Not all muscles are highlighted here,

0:11:10.960,0:11:15.520
but the reason why I’m showing you this is
because these muscles they tense up during

0:11:15.520,0:11:21.520
activity and help preserve the arch’s curvature.
Now, let’s take this view of the foot, and cut it

0:11:21.520,0:11:27.280
right about here, then look at it from the front.
Here we can clearly see the transverse arch. It

0:11:27.280,0:11:31.760
spans across the midfoot, and it’s supported
by several muscles, especially the tibialis

0:11:31.760,0:11:37.520
anterior and the fibularis longus. You can see
how tibialis anterior pulls from the medial side

0:11:37.520,0:11:43.120
and fibularis longus loops underneath and pulls
from the lateral side, creating a sling-like

0:11:43.120,0:11:48.960
support that lifts the arch from both ends.
These arches give the foot its shock-absorbing

0:11:48.960,0:11:52.640
quality and help distribute weight
during walking and standing.

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But sometimes things go wrong.
If the medial arch is too high,

0:11:56.720,0:12:01.760
it’s called pes cavus. This leads to poor shock
absorption, increased pressure on the heel

0:12:01.760,0:12:07.280
and forefoot, and often pain or instability.
On the other extreme, if the arch collapses,

0:12:07.280,0:12:12.800
we get pes planus, or flatfoot. This shifts
weight medially, often straining the plantar

0:12:12.800,0:12:17.600
ligaments and muscles. It can lead to
pain, poor posture, and altered gait.

0:12:17.600,0:12:20.720
To manage flatfoot, patients
often get orthotic insoles,

0:12:20.720,0:12:26.320
which are special inserts that help realign
the arch and support better foot mechanics.

0:12:26.320,0:12:30.480
Each of these arch defects alters the
weight distribution across the sole,

0:12:30.480,0:12:34.160
and you can actually see this in
a foot imprint. With a high arch,

0:12:34.160,0:12:39.920
the imprint shows only the heel and toes. With
flat footers, the whole sole makes contact.

0:12:39.920,0:12:42.800
These changes don’t just affect
the foot. They can throw off the

0:12:42.800,0:12:48.080
biomechanics of the entire lower limb, from
the ankle to the knee and even the hips.

0:12:48.080,0:12:52.320
So that was everything I had for the joints
and arches of the foot. And with that,

0:12:52.320,0:12:55.920
we’ve now officially covered all the
bones and joints of the lower limb,

0:12:55.920,0:13:00.960
wrapping up the entire skeletal anatomy series.
I’ve made a playlist for all of the skeletal

0:13:00.960,0:13:05.200
system videos in series here on YouTube, otherwise
if you want a handmade PDF version of this

0:13:05.200,0:13:08.880
lecture, take a quiz to test your knowledge,
or access an organized list of all my videos,

0:13:08.880,0:13:11.920
you can find everything on my website.
Thanks for watching! See you in the next one.