Description

This video covers the deep muscles of the back, organized into different layers and muscle systems.

Deep Muscles of the Back

3rd Layer

• Suboccipital Muscles
• System of Short Muscles

2nd Layer

• Transversospinal System

1st Layer (Superficial)

• Spinospinal System
• Spinotransverse System

1. Suboccipital Muscles

System of deep muscles of the neck.

• Rectus Capitis Posterior Minor (Musculus Rectus Capitis Posterior Minor)
  • Origin: Posterior Tubercle of Atlas (C1)
  • Insertion: Occipital Bone below Inferior Nuchal Line
• Rectus Capitis Posterior Major (Musculus Rectus Capitis Posterior Major)
  • Origin: Spinous Process of Axis (C2)
  • Insertion: Occipital Bone – Inferior Nuchal Line
• Obliquus Capitis Superior (Musculus Obliquus Capitis Superior)
  • Origin: Transverse Process of Atlas (C1)
  • Insertion: Occipital Bone – Inferior Nuchal Line
• Obliquus Capitis Inferior (Musculus Obliquus Capitis Inferior)
  • Origin: Spinous Process of Axis (C2)
  • Insertion: Transverse Process of Atlas (C1)

2. System of Short Muscles

Short muscles connecting adjacent vertebrae.

• Interspinales (Musculi Interspinales)
  • Developed mainly in the cervical and lumbar regions.
  • Origin: Spinous Process of vertebra below
  • Insertion: Spinous Process of vertebra above
• Intertransversarii (Musculi Intertransversales)
  • Mostly developed in the cervical region.
  • Located between transverse processes.
  • Origin: Transverse Process of vertebra below
  • Insertion: Transverse Process of vertebra above

3. Transversospinal System

Runs from the transverse process of a lower vertebra to the spinous process of an upper vertebra.

• Rotatores (Musculi Rotatores)
  • Located in the thoracic vertebrae.
  • Long Rotatores (Musculi Rotatores Longi)
    • Origin: Transverse Process of vertebra below
    • Insertion: Spinous Process of 2 vertebrae above
  • Short Rotatores (Musculi Rotatores Breves)
    • Origin: Transverse Process of vertebra below
    • Insertion: Spinous Process of 1 vertebra above
• Multifidi (Musculi Multifidi)
  • Fills space lateral to spinous processes.
  • Most distinctive in the lumbar region.
  • Short Multifidi (Musculi Multifidi Breves)
    • Origin: Transverse Process of vertebra below
    • Insertion: Spinous Process of 2 vertebrae above
  • Long Multifidi (Musculi Multifidi Longi)
    • Origin: Transverse Process of vertebra below
    • Insertion: Spinous Process of 3 vertebrae above
• Semispinalis (Musculi Semispinales)
  • Divided into thoracis, cervicis, and capitis.
  • Semispinalis Thoracis (Musculi Semispinalis Thoracis)
    • Origin: Transverse Process of T6-T11
    • Insertion: Spinous Process of C6-T4
  • Semispinalis Cervicis (Musculi Semispinalis Cervicis)
    • Origin: Transverse Process of T1-T6
    • Insertion: Spinous Process of C2-C5
  • Semispinalis Capitis (Musculi Semispinalis Capitis)
    • Origin: Transverse Process of C4-T6
    • Insertion: Occipital Bone – Between Inferior and Superior Nuchal Line

4. Spinospinal System

• Spinalis (Musculus Spinalis)
  • Spinalis Cervicis (Musculus Spinalis Cervicis)
    • Origin: Spinous Process of C6-T2
    • Insertion: Spinous Process of C2-C4
  • Spinalis Thoracis (Musculus Spinalis Thoracis)
    • Origin: Spinous Process of T10-L3
    • Insertion: Spinous Process of T1-T8

5. Spinotransverse System

• • Longissimus (Musculus Longissimus)

• Splenius (Musculus Splenius)
• Iliocostalis (Musculus Iliocostalis)

Transcript

Introduction
0:03
Hey What’s up. Meditay here and in this video, we’ll be covering the Deep muscles
0:07
of the back. Alright. Generally, the muscles of the back consist of superficial muscles
Division of the Back Muscles
0:12
and deep muscles. The superficial muscles consist of the The trapezius and Latissimus,
0:17
which are the 1st layer. The 2nd layer are the Rhomboid Major Minor and Levator
0:22
Scapula, and the 3rd layer of muscles consists of the Serratus Posterior superior and inferior.
0:29
And when you remove these three layers, you’ll finally get to the Deep muscles of the back.
Division of the Deep Back Muscles
0:34
Now the deep muscles of the back are categorized based on their shape and structure and location.
0:40
Generally, they consist of the Suboccipital Muscles, there’s the system of short muscles,
0:46
the Transversospinal system, Spinospinal system and then there’s the spinotransverse system.
0:53
The Suboccipital muscles consists of 4 muscles. These are the Rectus Capitis Posterior major and
1:00
Minor. And there’s the Obliquus Capitis Superior and Inferior. The system of short muscles consists
1:06
of the Interspinales and the Intertransversarii muscles. The muscles you see in front of you now,
1:12
are considered the 3rd Layer of the deep back muscles, meaning they’re
1:16
the deepest layer closest to the bone. Then we have the Transversospinal System,
1:21
which consists of the semispinalis, Multifidi and Rotatores.
1:26
The rotatores muscles consist of short and long muscle fibers. The short muscle fibers
1:31
of rotatores are considered a part of the 3rd layer since they’re as close to the
1:36
bones as the 3rd layer are. The long fibers of rotatores are considered a part of the 2nd layer,
1:42
as the multifidi and semispinalis are. Next we have the Spinospinal System,
1:48
which consist of Spinalis, and the Spinotransverse System, which consist of Splenius, Longissimus and
1:54
Iliocostalis. All of these are considered as the 1st layer of the deep muscles of the back, or the
2:00
most superficial ones. So these muscles are just below the superficial muscles of the back. Aight.
2:07
Even though the deep back muscles are divided into system of muscles,
2:11
they all share some common features. And that is that one; almost all the deep back muscles
2:17
originate and insert at the vertebra. And two; All share the same function, which is extension of the
2:24
vertebral column. So they provide stability of the vertebral column, and they help maintain our
2:30
posture and the natural curve of the spine. Let’s now cover all of these muscles,
2:34
starting with the 3rd layer, which are closest to the bones.
2:37
And we’ll start with these muscles you see here. Lets zoom in on them.
Suboccipital Muscles
2:41
The muscles you see here, are called; Suboccipital muscles, since.. well, they like sub occipitally,
2:48
and they’re therefore also considered as a system of deep muscles of the neck.
2:53
Ok. First, we have a muscle called the Rectus Capitis Posterior Minor,
2:58
which originate at the Posterior tubercle of Atlas, and Insert at the Occipital bone
3:03
below the inferior nuchal line. Then we have the Rectus Capitis Posterior Major,
3:09
which originate from the spinous process of Axis, and insert at the inferior nuchal
3:14
line of the occipital bone. So these are the Rectus Capitis Posterior muscles.
3:20
Then we have the Oblique muscles of the head. The Obliqus capitis Superior, which oritinate
3:25
at the transverse process of Atlas, and insert at the inferior nuchal line of the occipital bone.
3:30
And the Obliquus Capitis Inferior, which originate at the spinous process of Axis,
3:36
and insert at the Transverse Process of Atlas. So that was the suboccipital muscles.
System of Short Muscles
3:43
Next, we have the muscles shown here between the vertebrae. They’re called the System of Short
3:47
muscles. And the system of short muscles are a system connecting adjacent vertebra together.
3:54
And they consist of the Interspinales, which are here.
3:57
The interspinales are mostly developed in the Cervical and Lumbar region, but they’re also
4:02
present in the thoracic region with less muscle fibers. The interspinales are located between
4:07
the spinous processes. They originate from the spinous process of the vertebra below, and insert
4:14
at the spinous process of the vertebra above. The other muscle is called Intertransversarii,
4:19
which are here. They’re mostly developed in the cervical region, and they lie between
4:24
the transverse processes of the vertebra. They originate from the transverse process
4:29
of the vertebra below, and Insert at the transverse process of the vertebra above.
4:34
So that was the 3rd layer of the deep back muscles. Awesome. Now let’s do the 2nd layer.
Transversospinal System
4:39
Remember they’re the Transversospinal system. The transversospinal system are
4:44
a system of muscle fibers that go from the transverse process of the lower vertebra
4:49
to the spinous process of the upper vertebra. It kinda make sense when looking at the name.
4:55
The first ones are the Rotatores muscles. The rotatores muscles are deep muscles located in
5:01
the thoracic region, and they consist of long and short fibers. The long rotatores, which are here,
5:08
originate from the transverse process of the vertebra below, and insert at the spinous process
5:13
of 2 vertebra above. So it skips one vertebra. The short Rotatores muscle however,
5:19
these ones. Are generally considered as a part of the 3rd layer of deep back muscles,
5:24
together with the suboccipital and the interspinales and intertransversarii as
5:28
we looked at earlier. They originate at the transverse process of the vertebra below and
5:33
insert at the spinous process of 1 vertebra above. So that’s these ones. Then we have some slightly
5:41
larger muscles, called multifidi. The multifidi muscles fill the space lateral to the spinous
5:48
process. And they’re more distinctive at the lumbar region. The multifidi also consist of
5:54
short and long fibers. The short multifidi muscles, go like this. They originate at
6:00
the transverse process of the vertebra below and insert at the spinous process of 2 vertebra above.
6:07
The Long multifidi muscles originate at the transverse process of the vertebra below
6:12
and insert at the spinous process of 3 vertebra above. So that’s generally
6:17
how the multifidi muscles are arranged. Next we have the Semispinalis, which are here.
6:23
They consist of three parts. Let’s go through them.
6:26
First, we have the Semispinalis Thoracis, which are here highlighted in green. They originate
6:31
at the transverse Process of T6 through T12, and insert at the spinous process of C6 to T4
6:40
Then there’s the Semispinalis Cervicis, which is here in yellow.
6:44
This one originates from the transverse process of T1-T6, and insert at the Spinous Process of C2-C5.
6:53
And the last part is the Semispinalis Capitis, which is here in purple.
6:57
This one originates from the Transverse Process of C4 to T6,
7:02
and insert at the Occipital Bone, between the inferior and superior nuchal line.
7:07
So that was all the muscles of the Transversospinal system.
7:11
The 2nd layer of the deep back muscles. Now let’s finally do the 1st layer, which
7:16
is the most superficial layer just underneath the superficial muscles of the back, The first
Spinospinal System
7:21
ones are here. They’re called the Spinospinal System. Because they go from the spinous process
7:26
of the lower vertebra to the spinous process of the upper vertebra. So surprisingly enough,
7:32
these muscles are called Spinalis Muscles. And they’re made up of 2 muscles.
7:36
One is in the cervical region, called Spinalis Cervicis.
7:40
They originate from the spinous process of C6 to T2 and insert at the spinous process of C2 to C4.
7:48
The other one is at the Thoracic region, called Spinalis Thoracis.
7:52
It originates from the spinous process of T10 to L3 and insert at the spinous process of T1-T8.
8:01
So that’s this one. Then there’s another large muscle that’s considered the 1st layer of the
8:08
Deep back muscles. And they’re the Spinotransverse System, which are a system of fibers that go from
Spinotransverse System
8:14
the spinous process of the lower vertebra to the transverse process of the upper vertebra. And
8:19
they’re called the Longissimus Muscles. There are 3 parts. First there’s the Longissimus Thoracis,
8:25
which originate from the dorsal surface of sacrum, as you see here.
8:29
The Iliac Crest and the spinous process of T11 to L5. And they insert at the transverse process of
8:36
T1 to T12, as well as the costal angle of the 2nd to 12th rib. Or some sources might say from the
8:44
3rd to the 12th rib. These origin and insertion points really differ from source to source.
8:49
Then there’s the Longissimus Cervicis. This one. It originates from the transverse
8:54
process of T1-T6, and insert at the transverse process of C2-C5
9:01
Then there’s the Longissimus Capitis, which is here in yellow.
9:04
It originates from the transverse process of C4 to T4, and insert at the mastoid process.
9:13
Then there’re some large muscles up here, called Splenius Muscles, which are divided
9:18
into two set of muscle fibers. There’s the Splenius Capitis,
9:22
which originate at the spinous process of C3-T3 and insert at the mastoid process.
9:29
Then there’s the Splenius Cervicis, which originate at the spinous process of T3 to T6
9:35
and insert at the Transverse process of C1-C2. So that’s these ones.
9:41
The last one is the Iliocostal muscle, as you see here. And there are three parts
9:46
to this muscle based on the location as well. There’s the Iliocostalis Lumborum,
9:51
which originate at the thoracolumbar fascia, the Iliac crest and the Dorsal Sacrum. And
9:57
then it inserts at the 6 lower ribs. Then there’s the Iliocostalis Thoracis,
10:02
which originate at the 6 lower ribs and insert at the 6 upper ribs.
10:08
Then there’s the Iliocostalis Cervicis, which originate the 6
10:12
upper ribs, and insert at the Transverse Process of C4 to C6.
10:17
Awesome. So that was all the deep muscles of the back.
Summarize
10:21
We’ve covered the Spinospinal system and the Spinotransverse system, which are considered a
10:26
part of the 1st layer, the most superficial one. We’ve gone through the Transversospinal system,
10:31
which are considered a part of the 2nd layer, except the short muscle fibers of
10:35
rotatores muscles, they’re considered a part of the 3rd layer. And we’ve gone through the
10:40
suboccipital muscles and the system of short muscles, which are considered the 3rd and the
10:45
deepest muscles we have in the back. And that my friends are the deep muscles of the back.