Test your understanding with 10 random multiple-choice questions from the question bank.
This video covers the muscles of the leg, including their origins, insertions, and functions.
These muscles function as extensors of the leg. Their tendons pass under the extensor retinaculum.
Innervation: Deep Fibular Nerve
These muscles originate on the lateral surface of the fibula and run behind the lateral malleolus under the superior and inferior fibular retinaculum.
Innervation: Superficial Fibular Nerve
These muscles run behind the medial malleolus under the flexor retinaculum.
Innervation: Tibial Nerve
Introduction
0:03
What’s up. Meditay here and in this video, we’ll be covering the muscles of the Leg. Alright. So,
0:08
the muscles of the lower limb are divided into 4 parts according to their anatomical location.
0:13
The first group are muscles of the Hip Joint. Then we have the muscles of the Thigh, muscles
0:18
of the Leg and then the muscles of the Foot. So again, the muscles of the Leg are what
Division of the Leg Muscles
0:22
we’re gonna focus on in this video. And they’re divided into three main groups based on their
0:27
anatomical location. They’re divided into the Anterior group, which consist of 3 muscles.
0:32
We have the Lateral group of 2 muscles, and the Posterior group of 6 muscles layered as deep and
0:38
superficial. So let’s work our way through all of the muscles, starting with the anterior group.
Anterior Group
0:43
Awesome. Ok. So the muscles of the anterior group are what we call the extensors of the leg muscles,
0:49
because well they all cause extension of the foot. The tendons of these muscles pass underneath the
0:55
extensor retinaculum. The extensor retinaculum are bands of ligaments on the region of the ancle,
1:02
which organizes the tendons into groups. We’ll talk more about this briefly when
1:06
we cover the fascia of the lower limb. Another thig they have in common is that
1:11
they all are innervated by the deep fibular nerve. Awesome. Now let’s covert eh muscles.
1:16
The first one is the Extensor Hallucis Longus. This one. This muscle originates from the medial
Extensor Hallucis Longus
1:23
surface of the Fibula, as you see here. And it inserts at the Distal Phalanx of the Big toe.
1:28
And when it contracts, it causes extension of the big to, extension of the foot and
1:33
also supination and adduction of the foot. Then we have the Extensor Digitorum Longus,
Extensor Digitorum Longus
1:39
which is this long muscle here. It originates from the Lateral
1:43
Condyle of the Tibia, it originates from the Fibula and the interosseous membrane,
1:47
which is the membrane between the Tibia and Fibula. This muscle then inserts at the middle
1:52
and distal phalanx of the 2nd to 5th toe, as well as the 5th metatarsal bone. And when it contracts,
1:58
it causes extension of the 2nd to 5th toe, as well as extension of the foot. Then we
Tibialis Anterior
2:04
have the Tibialis Anterior, which is this one. It originates from the Lateral condyle of the
2:08
Tibia and the Lateral Surface of the Tibia And the Interosseous membrane.
2:13
Then it’s going to insert at the Base of the 1st metatarsal bone as well as the medial
2:18
cuneiform of the foot. And when it contracts,
2:21
it’s going to cause extension of the foot, as well as supination and adduction of the foot
2:26
So that was the anterior group of the leg. Cool. Let’s now do the Lateral group.
Lateral Group
2:32
The Lateral group consist of two fibular muscles that originate on
2:36
the lateral surface of the Fibula. Tendons of both muscles run behind
2:40
the lateral malleolus under the superior and inferior fibular retinaculum. Again,
2:46
it’s formed by the fascia of the leg. And they’re both innervated by the superficial fibular nerve.
2:52
Aight. So the first one is Fibularis Brevis, which is this one.
Fibularis Brevis
2:56
It originates from the lateral surface of Fibula and insert at the base of the 5th metatarsal bone.
3:02
It’s function is flection of the foot, as well as pronation and abduction of the foot.
3:07
So that’s this one. Next, we have the Fibularis Longus. And the fibularis longus
Fibularis Longus
3:12
covers the whole lateral aspect of the leg. It originates from the fibula as well,
3:18
both the head and the body of fibula. And it inserts at the base of the 1st metatarsal bone
3:23
and the medial cuneiform on the plantar surface, as you see here. So once it passes behind the
3:29
lateral malleolus, it goes on the plantar surface and attaches to these two bones.
3:34
And then its function is flexion of the foot, as well as pronation and abduction of the foot.
3:40
So that was the lateral group. Now let’s go ahead and turn the leg around and cover
Posterior Group – Deep
3:45
the posterior group of the leg. The Posterior group muscles are divided into a Deep layer,
3:51
and a Superficial Layer These layers are separated by a deep fascia, or a deep lamina.
3:57
As always, we’ll start with the deep layer first. The deep layer consists of 4 muscles,
4:03
and tendons of these muscles run behind the medial malleolus under the flexor retinaculum.
4:08
And all of these muscles are innervated by the Tibial Nerve. Aight. The first one is
Popliteus
4:13
the Popliteus Muscle, as you see here. It originates from the lateral condyle
4:17
of the femur, and it inserts at the posterior surface of the Tibia, above the soleal line as
4:23
you see here. It causes flexion and internal rotation of the leg. So that’s this one.
Tibialis Posterior
4:31
Then there’s the Tibialis Posterior. This one. The tibialis Posterior originates
4:36
from the posterior surface of the Tibia and Fibula, as well as the interosseous membrane.
4:41
And it inserts at the navicular and medial cuneiform on the plantar surface
4:46
as you see here. Most flexor muscles end up on the plantar surface of the foot.
4:51
This muscle is going to flex the foot. And it’s going to be supinating and adducting the foot.
4:58
So that’s the Tibialis Posterior. Then there’s the Flexor Digitorum Longus. Which is this one.
Flexor Digitorum Longus
5:04
This muscle originates form the posterior surface of the Tibia, and the interosseous
5:09
membrane. And then it’s going to insert at the Distal Phalanges of the 2nd to 5th toes.
5:14
As you see here, on the plantar surface. It’s just going to flex the foot
5:18
and flex the toes. That’s this one.
Flexor Hallucis Longus
5:22
Then there’s the flexor hallucis Longus. The flexor hallucis longus originates from the Fibula
5:27
and the interosseous membrane. And it’s going to insert at the distal phalanx of the big toe
5:32
as you see here. It’s function is flexion of the foot. Supination and adduction of the foot. And
5:38
flexion of the big toe. So that was the deep layer. Cool, let’s do the superficial layer.
Posterior Superficial Layer
5:44
The superficial layer mainly, consists of the Triceps Surae muscle. And the Triceps Surae
Triceps Surae
5:50
is a Tri-ceps, so three parts to this muscle. There’s the soleus, which is the deepest part.
5:57
It originates from the head of fibula; it originates from the Soleal line and
6:02
the posterior surface of the tibia. And it originates from the tendinous arch of the soleus
6:07
which is a fibrous arch formed by fascia. The other two parts of the triceps surae are located
6:14
superficially to the soleus, as you see here. They are called the Medial head of gastrocnemius,
6:20
which originate at the medial epicondyle of femur. And the Lateral head of gastrocnemius, which
6:25
originate at the lateral epicondyle of the femur. It then insert at the Achilles Tendon,
6:31
or the calcaneal tendon, which further inserts at the calcaneal tuberosity.
6:36
The main function of this muscle is flexion of the foot. The gastrocnemius muscles
6:41
Flexes of the Leg since they originate at the femur. They also help stabilize the knee joint
Plantaris
6:47
Then we have a muscle called musculus Plantaris. Which is this one. You barely see it here. But
6:52
if we fade the triceps surae, you’ll b able to see it better. It originates from
6:57
the Lateral condyle of the femur. It then passes underneath the gastrocnemius muscles
7:02
and then insert at the Achilles tendons, to then insert at the calcaneal tuberosity on calcaneus.
7:09
It’s function is flexion of the foot and flexion of the leg.
7:12
So that was the superficial layer of the Posterior group. And that was all the muscles of the leg.
7:18
In the next video, we’ll be covering the muscles of the foot.
©Copyright 2025 for Taimtalksmed. Powered by Abdalrahman Atwah.
