Muscles Flashcards
Origin:
- Medial Crest of sacrum (Via broad tendon)
- Lateral Crests of Sacrum
- Dorsal SI and Sacrotuberous Ligament
- Posterior part of Medial Lip of Iliac Crest
- T11-L5 SP’s
- Supraspinous Ligament
Insertion:
- Inferior border of angles of lower 6 or 7 ribs
FD:
Mostly vertical but somewhat lateral
Action:
- Extension of the vertebral column
- Side bending
- Rotation
R:
- Sacrum stuck in a flexed position will affect Iliocostalis lumborum
- Pulls on Sacrotuberous ligament which then pulls on biceps femoris
Iliocostalis Lumborum
Longissimus Thoracis
Origin:
- Iliocostalis Lumborum
- TP’s T11-L5
- TLF
Insertion: (2 tendons)
- Thoracic TPs T12-T2
- Lower 9 or 10 Ribs (between tubercles and angles)
Action:
- Extension and SB
Semispinalis Capitis
Origin:
- Upper 6 or 7 Thoracic TP’s
- C7 TP
- Cervical Articular Processes C4-6
Insertion:
- Between superior and inferior nuchal lines of occipital bone
R:
Much larger in comparison to semispinalis cervicis If a muscle attaches into the processes it helps with joint position sense 2-3x larger than SCM is CSA (Cross sectional area)
Nerve: Greater occipital artery + nerve
Origin:
- C7-T11 TP
Insertion:
- Rib below respective TP
Action:
- rotation of vertebrae
- lateral flexion of vertebrae
- elevates the ribs (aids in respiration)
- Stabilizes the rib
FD:
Inferior and lateral
Nerve:
Innervation is from lateral branches of the dorsal rami of the corresponding thoracic spinal nerves
D:
- 12 pairs -on internal aspect of thoracic cage
- The lower 4 muscle pairs may have an additional attachment to the second rib below their origin
Levator Costarum
Rectus Abdominus
Origin:
- Symphysis Pubis
- Pubic Crest
Insertion:
- Anterior Surface of Xiphoid Process
- Anterior Surface of Costal Cartilages 5-7
Action:
- flexes pelvis and vertebral column
- compresses abdomen
- supports viscera
Nerve:
ventral rami of T7-11
Role:
The role of the transverse lines between the abs is to prevent compression of the abdominal organs during flexion
divided by 3 horizontal lines of connective tissue which divide RA and tighten it down to increase mechanical advantage
One large strap muscle would lead to increased force production over a greater range of motion
The sectioned RA limits bulking upon shortening, but also leads to a bead effect, facilitating torso flexion and extension as the visceral contents change volume
Levator Costarum
Origin:
- C7-T11 TP
Insertion:
- Rib below respective TP
Action:
- rotation of vertebrae
- lateral flexion of vertebrae
- elevates the ribs (aids in respiration)
- Stabilizes the rib
FD:
Inferior and lateral
Nerve:
Innervation is from lateral branches of the dorsal rami of the corresponding thoracic spinal nerves
D:
- 12 pairs
- on internal aspect of thoracic cage
- The lower 4 muscle pairs may have an additional attachemtn to the second rib below their origin
Quadratus Lumborum
Origin:
- Iliolumbar Ligament (Superior/Posterior aspect)
- Posterior aspect Iliac Crest
- TLF
Insertion:
- Lower border of 12th Rib
- L1-4 TP’s
Action:
- depresses 12th rib in respiration
- aids in extension of the trunk
- unilaterally side bends the trunk
- closely related with psoas
Nerve:
dorsal rami of the spinal segment (T12-L3)
R:
- Merges with the diaphram and thus assits in breathing
- if it goes into spasm affecting the thoracic diaphram something else needs to compensate and help us breathe properly
– which is usually are neck muscle (Scalenenes) which increase in tone to lift up the first and second ribs more. Person could come in with TOS but real cause is QL disfunction.
What has a great PSCA QL or glute med? QL
Trendelenburg is both a glute med and QL test
Transverse Abdominus
Origin:
- Lower 6 CC (Inner Surface)
- Middle layer of Fascia
- Anterior 2/3 of inner lip of Iliac Crest -
Lateral 1/3 of Inguinal Ligament
Insertion:
- Linea Alba
- Pubic crest
- Pectineal line
Action:
force attenuation
Stabilization
Protection of organs
Nerve:
T7-12, L1 iliohypogastric and ilioinguinal ligament
R:
A weakness of the internal obliques permits a bulging of the anterior abdominal wall, which indirectly tends to increase lordosis. It also helps to stabilize the linea alba, permitting better action by the anterolateral trunk muscles
Iliocostalis Lumborum
Origin:
- Medial Crest of sacrum (Via broad tendon)
- Lateral Crests of Sacrum
- Dorsal SI and Sacrotuberous Ligament
- Posterior part of Medial Lip of Iliac Crest
- T11-L5 SP’s
- Supraspinous Ligament
Insertion:
- Inferior border of angles of lower 6 or 7 ribs
FD:
Mostly vertical but somewhat lateral
Action:
- Extension of the vertebral column
- Side bending
- Rotation
R:
- Sacrum stuck in a flexed position will affect Iliocostalis lumborum
- Pulls on Sacrotuberous ligament which then pulls on biceps femoris
Origin:
- Lower 6-10 Thoracic TP’s
Insertion:
- Upper 4-8 Thoracic SP’s
- Lower 2 Cervical SP’s
FD:
Vertical, slightly oblique
Action:
Aids in proprioception and segmental stabilization, A little extension, A little side bending, Some rotation
R:
Part of the transversospinalis group Acts as static postural muscles of the vertebral column affects OA joint
Semispinalis Thoracis
Origin:
- 3-6 Thoracic SP
Insertion:
- Posterior Tubercles of Upper 2 or 3 Cervical TP’s
Action:
side bends and rotates upper thoracic, cervical and OA joints
Relationship: Deeper
Splenius Cervicis
Spinalis Thoracis
Origin:
- T11-L2 SP’s
Insertion:
- Upper 4-8 Transverse SP’s
Longissimus Capitus
Origin:
- Upper 4 or 5 Thoracic TPs
- Lower 3 or 4 Cervical Articular Processes
Insertion:
- Mastoid Process
Action:
- Extension, lateral flexion and rotation of the cervical spine; turning the head to face toward the same side
- Extension of the the neck and head, rotation and a little side bending of neck and head
Spinalis Capitis
Origin:
- Upper 6 or 7 Thoracic TP’s
- C7 TP
- 4th-6th Cervical Articular Processes
Insertion:
- Area between Superior/Inferior Nuchal Lines
Relationship:
- inseparably connected with semispinalis capitis
Splenius Capitis
Origin:
- Lower ½ of Ligamentum Nuchae
- C7 SP - Upper 3 or 4 Thoracic SP
Insertion:
- Mastoid Process
- Occipital Bone inferior to lateral 1/3 of Superior Nuchal Line
FD:
ascend laterally
**Action: **
- extension, lateral flexion and rot’n
Role:
more superficial
Spinalis Cervicis
Origin:
- Lower 1/2 Ligamentum Nuchae
- C7 SP
Insertion:
- SP of Axis (C2)
- Occasionally into SP’s of C3 + C4
Relationships:
Extension of supraspinous ligament
50% of your rotation occurs at C2
Origin/Insertion:
- Between SP’s
- Cervical = 6 pairs
- Thoracic = 2 or 3 pairs
- Lumbar = 4 pairs
Function/Role:
- aids Erector Spinae in extension
-placed in pairs between spinous processes of continuous vertebrae
Interspinales
Obliqus Externus
Origin:
- External Surface Lower 8 Ribs
Insertion:
- Anterior ½ Iliac Crest
- Linea Alba
- Inguinal ligament
Action:
- compresses abdomen
- supports viscera
- forced expiration
- first part of trunk flexion
Nerve:
T7-11
Role:
The upper portion merges with seratus anterior
Lower portion merges with the lats
Intertransversarii
Origin/Insertion:
- Between TP’s
Action:
side bends vertebral column
Role:
- small muscles placed between Tp’s of continuous vertebrae in cervical, thoracic and lumbar regions
- 4.5 – 7.3 times the muscles spindles than multifidus
- Length transducers
– position sensors
Origin:
- Iliocostalis Lumborum
- TP’s T11-L5
- TLF
Insertion: (2 tendons)
- Thoracic TPs T12 - T2
- Lower 9 or 10 Ribs (between tubercles and angles)
Action:
- Extension and SB
Longissimus Thoracis
Transverse Thoracus
Origin:
- Xiphoid Process (Inner Surface)
- Sternum up to Rib 3 (Inner Surface)
Insertion:
- Ribs 2-7 + CC (Inner Surface)
Action:
- aids in expiration and depression of ribs 2-7
Nerve:
Innervation is from the corresponding intercostal nerves
Origin:
- External Surface Lower 8 Ribs
Insertion:
- Anterior ½ Iliac Crest
- Linea Alba
- Inguinal ligament
Action:
- compresses abdomen
- supports viscera
- forced expiration
- first part of trunk flexion
Nerve: T7-11
Role: The upper portion merges with seratus anterior Lower portion merges with the lats
Obliqus Externus
Origin:
- Upper 6 or 7 Thoracic TP’s
- C7 TP
- 4th-6th Cervical Articular Processes
Insertion:
- Area between Superior/Inferior Nuchal Lines
Relationship:
- inseparably connected with semispinalis capitis
Spinalis Capitis
Origin:
- Lower Thoracic or Upper Lumbar TP’s
Insertion:
- Brevis = Lamina of vertebrae above
- Longus = 2 above
Action: Side bend, rot, ext
Stress: Flexion will stretch or lengthen Rotatores
Role: - 4.5 – 7.3 times the muscles spindles than multifidus - Length transducers – position sensors
- Brevis spans one segment
- Longus spans up 2 segments above -11 pairs
Rotatores (Third Layer)
Origin:
- Lower ½ of Ligamentum Nuchae
- C7 SP
- Upper 3 or 4 Thoracic SP
Insertion:
- Mastoid Process
- Occipital Bone inferior to lateral 1/3 of Superior Nuchal Line
FD: ascend laterally
Action:
- extension, lateral flexion and rot’n
Role: more superficial
Splenius Capitis
Origin:
- Superior borders of angles of lower 6 ribs
Insertion:
- Superior border of angles of upper 6 ribs
- C7 TP
Action:
- extension
- side bending
Iliocostalis Thoracis
Origin:
- Upper 6 or 7 Thoracic TP’s
- C7 TP
- Cervical Articular Processes C4-6
Insertion:
- Between superior and inferior nuchal lines of occipital bone
Role:
Much larger in comparison to semispinalis cervicis If a muscle attaches into the processes it helps with joint position sense 2-3x larger than SCM is CSA (Cross sectional area)
Nerve: Greater occipital artery + nerve
Semispinalis Capitis
Semispinalis Thoracis
Origin:
- Lower 6-10 Thoracic TP’s
Insertion:
- Upper 4-8 Thoracic SP’s
- Lower 2 Cervical SP’s
FD:
Vertical, slightly oblique
Action:
Aids in proprioception and segmental stabilization, A little extension, A little side bending, Some rotation
Role:
Part of the transversospinalis group Acts as static postural muscles of the vertebral column affects OA joint
Origin:
- T11-L2 SP’s
Insertion:
- Upper 4-8 Thoracic SP’s
Spinalis Thoracis
Origin:
- Superior Border of Ribs + CC
Insertion:
- Rib + CC above
FD:
- is up and medial (perpendicular to Externi)
- Up & lateral on the posterior aspect
Action:
- supports intercostal space (maintains space)
- lowers rib in forces expiration
D: 11 pairs
Role: From the rib angles, they continue as an aponeurotic layer called the internal intercostal membrane and blend with the superior CT ligament
Intercostales Interni
Origin:
- Angles of Ribs 3-6
Insertion:
- Posterior Tubercles of TP’s C4-6
Action:
- extension
Iliocostalis Cervicis
Origin:
- Upper 4 or 5 Thoracic TPs
- Lower 3 or 4 Cervical Articular Processes
Insertion:
- Mastoid Process
Action:
- Extension, lateral flexion and rotation of the cervical spine; turning the head to face toward the same side
- Extension of the the neck and head, rotation and a little side bending of neck and head
Longissimus Capitus
Origin:
- T11, T12, L1, L2 Sp’s
- lumbar fascia
- Also the supraspinous ligament
Insertion:
- inferior border of lower 4 ribs just beyond their angles
FD: Oblique and lateral
Action:
-aids respiration & lowers ribs
Nerve:
-9th – 11th intercostal nerve
Role: lies immediately posterior to erector spinae
Serratus Posterior Inferior
Origin:
- Posterior Surface of Sacrum
- Medial Surface of PSIS
- Dorsal SI Ligament
- L5 - C4 TP’s
Insertion:
- SP’s above (Spans 2 - 4 segments)
Fibre Direction:
- Superior, Oblique and Medial
Function/Role:
Segemental stability (Large amount)
Relationships:
- If a spinal segment is in disfunction, not neccesarily pain, multifidus will start to atrophy within 24 hours -Some of the fibres will merge with the zygoapopheseal joint capsule - so able to give feedback to the body with regard to where the facets are, side bent, rotated etc. - Fibres arent neccesarily merging *Majority of the fibres will go from segment to segment
Multifidi
Interspinales
Origin/Insertion:
- Between SP’s
- Cervical = 6 pairs
- Thoracic = 2 or 3 pairs
- Lumbar = 4 pairs
Function/Role:
- aids Erector Spinae in extension
Relationship:
placed in pairs between spinous processes of continuous vertebrae
Origin:
- Sp’s of C7, T1, T2, T3
- lower part of ligamentum nuchae
- Supraspinous ligament
Insertion:
- upper border of ribs 2-5
- Inserts just lateral to the rib angles on their superior and superfical surfaces
Action:
-aids in respiration & elevates ribs
Nerve:
- 2nd – 4th intercostal nerves
Serratus Posterior Superior
Intercostales Externi
Origin:
- Inferior border of Rib below Tubercle
Insertion:
- Superior border of Rib below
FD:
is down & medial (Ant), down & lat (Post)
Action:
- supports intercostal space (protective)
- elevates rib in inspiration
D:
11 pairs
**R: **
Orginates from the tubercles of the rib, blending with the posterior fibres of the CT ligaments
Iliocostalis Cervicis
Origin:
- Angles of Ribs 3-6
Insertion:
- Posterior Tubercles of TP’s C4-6
Action:
- extension
Iliocostalis Thoracis
Origin:
- Superior borders of angles of lower 6 ribs
Insertion:
- Superior border of angles of upper 6 ribs
- C7 TP
Action:
- extension
- side bending
Origin:
- Xiphoid Process (Inner Surface)
- Lower 6 Ribs + CC (Inner Surface)
- Anterior Surface L1-L3
- Right/Left Crura
- Anterior Longitudinal Ligament
- IVD - Medial / Lateral Arcuate Ligaments
Insertion:
- Central Tendon
FD:
The medial tendinous margins of the crura pass anteriorly and medialward, and meet in the middle line to form an arch across the front of the aorta known as the median arcuate ligament; this arch is often poorly defined. The area behind this arch is known as the aortic hiatus.
N:
-innervated by phrenic nerve C3, C4, C5
R:
At their origins the crura are tendinous in structure, and blend with the anterior longitudinal ligament of the vertebral column. The right crus, larger and longer than the left, arises from the anterior surfaces of the bodies and intervertebral fibrocartilages of the upper three lumbar vertebrae. The left crus arises from the corresponding parts of the upper two lumbar vertebrae only. The medial fibers of the right crus ascend on the left side of the esophageal hiatus, and occasionally a fasciculus of the left crus crosses the aorta and runs obliquely through the fibers of the right crus toward the vena caval foramen. pericardial sac attaches to the diaphragm made up of 3 parts right, which is the largest and corresponds to right lung anterior, corresponding to heart left, which is the smallest and correspond to left lung
Holes of the Diaphragm: -vena cava -esophageal hiatus (formed by right crus) -aortic hiatus (formed where right and left crura meet superiorly)…aorta sits posterior to diaphragm and anterior to the vertebral column -phrenic nerve
Thoracic Diaphragm
Origin:
- Upper 5 or 6 Thoracic TP’s
Insertion:
- C2-C5 SP’s
Semispinalis Cervicis
Origin:
- Upper 4 or 5 Thoracic TPs
Insertion:
- Posterior Tubercles of TP’s C2-6
Action:
- Extension and SB
Longissimus Cervicis
Origin:
- Symphysis Pubis
- Pubic Crest
Insertion:
- Anterior Surface of Xiphoid Process
- Anterior Surface of Costal Cartilages 5-7
Action:
- flexes pelvis and vertebral column
- compresses abdomen
- supports viscera
Nerve:
ventral rami of T7-11
Role: The role of the transverse lines between the abs is to prevent compression of the abdominal organs during flexion divided by 3 horizontal lines of connective tissue which divide RA and tighten it down to increase mechanical advantage One large strap muscle would lead to increased force production over a greater range of motion The sectioned RA limits bulking upon shortening, but also leads to a bead effect, facilitating torso flexion and extension as the visceral contents change volume
Rectus Abdominus
Origin:
- TLF
- Anterior 2/3 of Iliac Crest (middle lip)
- Lateral 2/3 of Inguinal Ligament
Insertion:
Lower 3 CC
Linea Alba
Pubic Crest
Pectineal Line
Action:
Force closure of symphasis pubis compresses abdomen aids in expiration supports viscera flex the vertebral column
Nerve:
T9-12, L1 Iliohypogastric and ilioinguinal nerve
Role:
The more inferiorly placed portion of the muscle exerts a pull on the pelvis, a motion that is medially directed, effectively increasing compression of the pubic symphysis. This muscle can exert a powerful forward and elevation movement of the pelvis, a motion that is essential in sprinting
Obliqus Internus
Obliqus Internus
Origin:
- TLF
- Anterior 2/3 of Iliac Crest (middle lip)
- Lateral 2/3 of Inguinal Ligament
Insertion:
Lower 3 CC
Linea Alba
Pubic Crest
Pectineal Line
Action:
Force closure of symphasis pubis
compresses abdomen
aids in expiration
supports viscera
flex the vertebral column
Nerve:
T9-12, L1 Iliohypogastric and ilioinguinal nerve
R:
The more inferiorly placed portion of the muscle exerts a pull on the pelvis, a motion that is medially directed, effectively increasing compression of the pubic symphysis. This muscle can exert a powerful forward and elevation movement of the pelvis, a motion that is essential in sprinting
Longissimus Cervicis
Origin:
- Upper 4 or 5 Thoracic TPs
Insertion:
- Posterior Tubercles of TP’s C2-6
Action:
- Extension and SB
Origin:
- Xiphoid Process (Inner Surface)
- Sternum up to Rib 3 (Inner Surface)
Insertion:
- Ribs 2-7 + CC (Inner Surface)
Action:
- aids in expiration and depression of ribs 2-7
N:
-Innervation is from the corresponding intercostal nerves
Transverse Thoracus
Origin:
- Lower 1/2 Ligamentum Nuchae
- C7 SP
Insertion:
- SP of Axis (C2)
- Occasionally into SP’s of C3 + C4
R:
Extension of supraspinous ligament
50% of your rotation occurs at C2
Spinalis Cervicis
Splenius Cervicis
Origin:
- 3-6 Thoracic SP
Insertion:
- Posterior Tubercles of Upper 2 or 3 Cervical TP’s
A:
side bends and rotates upper thoracic, cervical and OA joints
R: Deeper than Splenius Capitus
Semispinalis Cervicis
Origin:
- Upper 5 or 6 Thoracic TP’s
Insertion:
- C2-C5 SP’s
Multifidi
Origin:
- Posterior Surface of Sacrum
- Medial Surface of PSIS
- Dorsal SI Ligament
- L5 - C4 TP’s
Insertion:
- SP’s above (Spans 2 - 4 segments)
Fibre Direction:
- Superior, Oblique and Medial
Function/Role:
Segemental stability (Large amount)
Relationships:
- If a spinal segment is in disfunction, not neccesarily pain, multifidus will start to atrophy within 24 hours
- Some of the fibres will merge with the zygoapopheseal joint capsule - so able to give feedback to the body with regard to where the facets are, side bent, rotated etc.
- Fibres arent neccesarily merging *Majority of the fibres will go from segment to segment
Origin:
- Inferior border of Rib below Tubercle
Insertion:
- Superior border of Rib below
FD:
is down & medial (Ant), down & lat (Post) Action:
- supports intercostal space (protective)
- elevates rib in inspiration
D: 11 pairs
R: Orginates from the tubercles of the rib, blending with the posterior fibres of the CT ligaments
Intercostales Externi
Origin:
- Lower 6 CC (Inner Surface)
- Middle layer of Fascia
- Anterior 2/3 of inner lip of Iliac Crest
- Lateral 1/3 of Inguinal Ligament
Insertion:
- Linea Alba
- Pubic crest
- Pectineal line
A:
force attenuation Stabilization Protection of organs Nerve:
T7-12, L1 iliohypogastric and ilioinguinal ligament
Role:
A weakness of the internal obliques permits a bulging of the anterior abdominal wall, which indirectly tends to increase lordosis. It also helps to stabilize the linea alba, permitting better action by the anterolateral trunk muscles
Transverse Abdominus
Rotatores
Origin:
- Lower Thoracic or Upper Lumbar TP’s
Insertion:
- Lamina of vertebrae above (Brevis)
- Longus = 2 above
A:
Side bend, rot, ext
S:
Flexion will stretch or lengthen Rotatores
R:
- 4.5 – 7.3 times the muscles spindles than multifidus
- Length transducers
– position sensors
- Brevis spans one segment
- Longus spans up 2 segments above
- 11 pairs
Origin:
- Iliolumbar Ligament (Superior/Posterior aspect)
- Posterior aspect Iliac Crest
- TLF
Insertion:
- Lower border of 12th Rib
- L1-4 TP’s
Action:
- depresses 12th rib in respiration
- aids in extension of the trunk
- unilaterally side bends the trunk
- closely related with psoas
Nerve:
dorsal rami of the spinal segment (T12-L3)
Role:
Merges with the diaphram and thus assits in breathing - if it goes into spaasm affecting the thoracic diaphram something else needs to compensate and help us breathe properly – which is usually are neck muscle (Scalenenes) which increase in tone to lift up the first and second ribs more. Person could come in with TOS but real cause is QL disfunction. What has a great PSCA QL or glute med? QL Trendelenburg is both a glute med and QL test
Quadratus Lumborum
Intercostales Interni
Origin:
- Superior Border of Ribs + CC
Insertion:
- Rib + CC above
FD:
-is up and medial (perpendicular to Externi) (Posterior aspect)
Action:
- supports intercostal space (maintains space)
- lowers rib in forces expiration
D:
11 pairs
R:
From the rib angles, they continue as an aponeurotic layer called the internal intercostal membrane and blend with the superior CT ligament
Serratus Posterior Inferior
Origin:
- T11, T12, L1, L2 Sp’s
- TLF
- Supraspinous ligament
Insertion:
- Inferior border lower 4 ribs (just beyond their angles)
FD:
Oblique and lateral
Action:
-aids respiration & lowers ribs
Nerve:
-9th–11th intercostal nerve
R:
lies immediately posterior to erector spinae
Thoracic Diaphragm
Origin:
- Xiphoid Process (Inner Surface)
- Lower 6 Ribs + CC (Inner Surface)
- Anterior Surface L1-L3
- Right/Left Crura
- Anterior Longitudinal Ligament
- Medial / Lateral Arcuate Ligaments
Insertion:
- Central Tendon
FD:
The medial tendinous margins of the crura pass anteriorly and medialward, and meet in the middle line to form an arch across the front of the aorta known as the median arcuate ligament; this arch is often poorly defined. The area behind this arch is known as the aortic hiatus.
N:
innervated by phrenic nerve C3, C4, C5
R:
At their origins the crura are tendinous in structure, and blend with the anterior longitudinal ligament of the vertebral column.
The right crus, larger and longer than the left, arises from the anterior surfaces of the bodies and intervertebral fibrocartilages of the upper three lumbar vertebrae.
The left crus arises from the corresponding parts of the upper two lumbar vertebrae only. The medial fibers of the right crus ascend on the left side of the esophageal hiatus, and occasionally a fasciculus of the left crus crosses the aorta and runs obliquely through the fibers of the right crus toward the vena caval foramen.
pericardial sac attaches to the diaphragm made up of 3 parts right, which is the largest and corresponds to right lung anterior, corresponding to heart left, which is the smallest and correspond to left lung
Holes of the Diaphragm:
- vena cava
- esophageal hiatus (formed by right crus)
- aortic hiatus (formed where right and left crura meet superiorly)…aorta sits posterior to diaphragm and anterior to the vertebral column -phrenic nerve
Origin/Insertion:
- Between TP’s
Action:
side bends vertebral column
Role:
- small muscles placed between Tp’s of continuous vertebrae in cervical, thoracic and lumbar regions - 4.5 – 7.3 times the muscles spindles than multifidus - Length transducers – position sensors
Intertransversarii
Serratus Posterior Superior
Origin:
- C7-T3 SP
- Lower 1/2 Ligamentum Nuchae
- Supraspinous ligament
Insertion:
- upper border of ribs 2-5
- Inserts just lateral to the rib angles on their superior and superfical surfaces
Action:
-aids in respiration & elevates ribs
Nerve:
- 2nd–4th intercostal nerves
