Description

This video covers the muscles of the thigh, including their origins, insertions, and functions.

Muscles of the Thigh

• Anterior Group [2]
• Medial Group [5]
• Posterior Group [3]

Anterior Group [2]

These muscles cover the entire anterior surface of the thigh.

Common Innervation: Femoral Nerve

Quadriceps Femoris (Musculus Quadriceps Femoris)

• Rectus Femoris
  • Origin: Anterior Inferior Iliac Spine
• Vastus Lateralis
  • Origin: Lateral Lip of Linea Aspera
• Vastus Medialis
  • Origin: Medial Lip of Linea Aspera
• Vastus Intermedius
  • Origin: Anterior Surface of Femur
• Insertion: Tibial Tuberosity through Patellar Ligament
• Function:
  • Extension of the Leg
  • Flexion of Femur

Sartorius (Musculus Sartorius)

• Origin: Anterior Superior Iliac Spine
• Insertion: Tibial Tuberosity (Tuberositas Tibiae)
• Function:
  • Flexion of Thigh and Leg
  • External Rotation of Thigh
  • Internal Rotation of Leg

Medial Group [5]

Pectineus (Musculus Pectineus)

• Origin: Pecten Pubis
• Insertion: Pectineal Line of Femur
• Function:
  • Adduction + Flexion of Thigh
  • External Rotation of Thigh

Adductor Brevis (Musculus Adductor Brevis)

• Origin: Inferior Pubic Ramus (Ramus Inferior Ossis Pubis)
• Insertion: Medial Lip of Linea Aspera (Labium Mediale Linea Aspera)
• Function:
  • Adduction + Flexion of Thigh
  • External Rotation of Thigh

Adductor Longus (Musculus Adductor Longus)

• Origin: Between Pubic Symphysis and Pubic Tubercle
• Insertion: Medial Lip of Linea Aspera (Labium Mediale Linea Aspera)
• Function:
  • Adduction + Flexion of Thigh
  • External Rotation of Thigh

Adductor Magnus (Musculus Adductor Magnus)

• Origin:
  • Inferior Pubic Ramus
  • Ischial Ramus
  • Ischial Tuberosity
• Insertion:
  • Medial Lip of Linea Aspera
  • Medial Epicondyle of Femur
• Function:
  • Adduction + Extension of Thigh
  • Internal Rotation of Thigh

Gracilis (Musculus Gracilis)

• Origin: Inferior Pubic Ramus
• Insertion: Tibial Tuberosity (Tuberositas Tibiae)
• Function:
  • Adduction of Thigh
  • Flexion of Leg
  • Internal Rotation of Leg

Posterior Group [3]

These muscles extend the hip joint and flex the knee joint.

Common Innervation: Sciatic Nerve

Biceps Femoris (Musculus Biceps Femoris)

• Long Head
  • Origin: Ischial Tuberosity (Tuber Ischiadicum)
• Short Head
  • Origin: Lateral Lip of Linea Aspera
• Insertion: Head of Fibula (Caput Fibulae)
• Function:
  • Flexion of the Leg
  • External Rotation of the Leg
  • Extension of the Thigh (Long Head)

Semitendinosus (Musculus Semitendinosus)

• Origin: Ischial Tuberosity (Tuber Ischiadicum)
• Insertion: Tibial Tuberosity (Tuberositas Tibiae)
• Function:
  • Flexion of the Leg
  • Internal Rotation of the Leg
  • Extension of the Thigh

Semimembranosus (Musculus Semimembranosus)

• Origin: Ischial Tuberosity (Tuber Ischiadicum)
• Insertion: Medial Condyle of Tibia (Condylus Medialis Tibiae)
• Function:
  • Flexion of the Leg
  • Internal Rotation of the Leg
  • Extension of the Thigh

Transcript

Introduction
0:03
What’s up. Meditay here and in this video, we’ll be covering the muscles you’ll find in the region
0:08
of the thigh, which as you know are a part of the muscles of the lower limb. Alright. So the
0:13
muscles of the lower limb are divided into 4 parts according to their anatomical location.
0:18
The first group are muscles of the Hip Joint. Then we have the muscles of the Thigh, muscles
0:22
of the Leg and then the muscles of the Foot. So again, muscles of the Thigh are what we’re
Division of the Thigh Muscles
0:27
gonna focus on today. And they’re divided into three main groups based ont heir anatomical
0:32
location. We have the Anterior group, which consist of 2 muscles. We have the Medial
0:37
group of 5 muscles, and the Posterior group of 3 muscles. So let’s work our way through all of the
Anterior Group
0:44
muscles here, starting with the anterior group. Awesome. Ok. So the muscles of the anterior
0:48
group cover the entire anterior surface of the thigh, they’re big big muscles. And they
0:54
all have one thing in common, which is that they’re all innervated by the femoral nerve.
0:59
Ok. SO first we have the Quadriceps Femoris, which is the main muscle group of the anterior region of
Quadriceps Femoris
1:05
the thigh. And the reason why I call this muscle a muscle group, is because it consists of 4 parts
1:11
that originate at different region. First, we have the Rectus Femoris, which is the most superficial
1:16
one here. It originates from the anterior inferior iliac spine. Then laterally, we have the vastus
1:23
lateralis, which originates at the lateral lip of the Linea aspera. There’s a Vastus Medialis,
1:28
which originate at the medial lip of Linea aspera. Then underneath all of those, there’s the vastus
1:35
intermedialis. So, if we remove the rectus femoris, we cans see it clearly here.
1:40
It originates from the anterior surface of the thigh.
1:43
Now. All of these muscles are going to joint distally to insert at a common place,
1:49
which is the tibial tuberosity, through a ligament called the patellar ligament as you see here.
1:54
The function of this muscle is forcefully extending the leg, as well as flexing the
1:59
femur. So that is the Quadriceps Femoris. Next we have the Sartorius Muscle located
Sartorius Muscle
2:05
superficially as you see here. The Sartorius muscle originates
2:09
from the anterior superior iliac spine, and it inserts at the tibial tuberosity.
2:15
This muscle will flex the thigh and leg. As well as externally rotating the thigh
2:20
and internally rotating the leg. So that’s the anterior group.
Medial Group: Pectineus
2:25
Now, let’s do the medial group, and so look at the thigh from a medial view.
2:30
First, we have the Pectineus, which is here. The pectineus muscle originates from the pecten pubis,
2:36
or pecten of pubis, and inserts at the pectineal line of the femur.
2:41
And its function is both adduction and flexion of the thigh, as well as externally rotating
2:47
the thigh. So that’s this one. Then we have the Adductor Brevis.
Adductor Brevis
2:51
And the adductor brevis, as you see here, originates from the inferior pubic ramus,
2:57
and it inserts at the medial lip of linea aspera. And its function is adduction and
3:02
flexion of the thigh, as well as externally rotating the thigh, just like the pectineus.
3:07
Then we have the Adductor Longus. This one. It originates on the pubic bone between the
Adductor Longus
3:12
pubic symphysis and the pubic tubercle, and it inserts at the medial lip of linea aspera.
3:18
And its function is the same as the last two, which is adduction and flexion of the thigh.
3:24
And externally rotating the thigh. So that’s that one. Then we have the Adductor Magnus.
Adductor Magnus
3:30
The adductor magnus is a very large muscle on the medial side fo the thigh, and it originates from
3:36
the inferior pubic ramus, as well as the Ischial Ramus and the Ischial Tuberosity. And then it’s
3:42
going to insert at the medial lip of linea aspera, as well as the medial epicondyle of the femur.
3:48
Its function is adduction and extension of the thigh, and internal rotation of the thigh.
3:54
Aight. Then we have the Gracilis. And the gracilis is a superficial muscle here on
Gracilis
4:00
the medial side. It originates from the inferior pubic ramus, and insert at the tibial tuberosity.
4:07
Its function is to adduct the thigh. Flex the Leg and Internal rotation of the leg.
4:13
So that was all the muscles of the medial group. Take a mental picture. Remember
Posterior Group
4:18
these muscles. And let’s continue with the posterior group of muscles.
4:21
The posterior group at the extensors of the hip joint and the flexors of the knee joint. So they
4:28
pull the whole leg backwards. They all have common innervation which is from the sciatic nerve.
4:36
Aight. The first muscle is the Biceps Femoris, which is this one.
Biceps Femoris
4:40
And just like the biceps brachii, the biceps femoris consists of a Long head,
4:45
which originates from the ischial tuberosity, and a short head, which
4:49
originate from the lateral lip of linea aspera. It then inserts at the head of the Fibula.
4:56
The function of this muscle is flexion of the leg. External rotation of the leg,
5:00
and extension of the thigh. Where only the long head causes extension of the thigh since this is
5:06
the only head that originate from the hip and not the thigh. Then we have the Semitendinosus muscle,
Semitendinosus
5:12
which is this one. It originates from the ischial tuberosity, and insert at the Tibial Tuberosity.
5:18
And its function is the same, it’s flexion of the Leg, internally rotation
5:22
of the leg and extension of the thigh. Aight. The last one is the Semimembranosus.
Semimembranosus
5:29
The semimembranosus is located behind the semitendinosus as you see here. It’s larger as
5:35
well. It originates from the ischial tuberosity and insert at the medial condyle of the tibia.
5:42
Its function is flexion of the leg, internal rotation of the leg and extension of the thigh. So
5:48
that was the muscles of the posterior group. And that was the muscles of the thigh.
5:52
The next video is gonna be about the muscles of the Leg.