Intercostals

Intercostals

Origin:         Ribs 1-11

Insertion:    Ribs 2-12

Actions:      

• Elevation or Depression of the Ribs
• Maintains intercostal spaces

Synergist

Antagonist

Shortened

Lengthened

Internal Obliques

Internal Obliques

The internal obliques wrap around the waist and insert into the linea alba, a cord like strip of connective tissue running down the centre of the abdomen.

Origin

• Iliac crest
• Inguinal ligament

Insertion

• Costal cartilages of lower 4 ribs
• Abdominal aponeurosis into Linea alba

Actions

• Unilaterally: bends the trunk to that side
• Ipsilateral rotation of trunk
• Bilaterally: Flexion of spine
• Compresses the abdomen and supports the abdominal viscera

Daily uses

• Raking leaves

Synergist

Antagonist

Shortened

Lengthened

Quadratus Lumborum

Quadratus Lumborum

The quadratus lumborum or QL is a common cause of back pain which is to one side and comes on after lifting or twisting.

Origin

• Posterior iliac crest

Insertion

• Twelfth rib
• Transerve processes of L1-L4

Actions

• Laterally flexes (side-bends) trunk,
• elevation of hip
• Bilaterally: extension of lumbar spine

Daily uses

• Bending sideways to pick something up

Synergist

Extension

• Spinalis (Bilaterally)
• Longissimus (Bilaterally)
• Iliocostalis (Bilaterally)
• Multifidi
• Rotatores
• Semispinalis

Lateral flexion

• External Oblique (To Same Side)
• Internal Oblique (To Same Side)
• Latissimus Dorsi
• Spinalis (Unilaterally)
• Longissimus (Unilaterally)
• Iliocostalis (Unilaterally)

Antagonist

Extension

• Rectus Abdominus
• External Oblique (Bilaterally)
• Internal Oblique (Bilaterally)

Shortened

bend to side

Lengthened

bend to opposite side.

Rectus Abdominus

Rectus Abdominus

Rectus Abdominus is the most superficial of the abdominal muscles. It is this muscle which forms the six-pack shape!

Origin

• Crest of the pubis
• Pubic symphesis

Insertion

• Xiphoid process (base of the sternum)
• 5th,6th and 7th costal cartilages

Actions

• Flexes lumbar spine
• Compression of abdominal contents

Daily uses

• Moving from lying to sitting

Synergist

Flexion

• External Oblique (Bilaterally)
• Internal Oblique (Bilaterally)

Antagonist

Extension

• Spinalis (Bilaterally)
• Longissimus (Bilaterally)
• Iliocostalis (Bilaterally)
• Multifidi
• Rotatores
• Semispinalis
• Quadratus Lumborum
• Latissimus Dorsi (When Arm is Fixed)

Shortened

Crunch

Lengthened

bridge pose

Transverse Abdominus

Transversus Abdominus is often abbreviated to TVA. This is a very important core muscle which is vital in maintaining good posture. Activities such as pilates focus on contraction of the TVA.

Origin

• Front of the iliac crest
• Inguinal ligament
• Costal cartilages of the lower 6 ribs
• Thoracolumbar fascia

Insertion

• Abdominal aponeurosis to Linea alba

Actions

• Compresses the abdomen and supports the abdominal visera

Daily uses

• Maintaining good posture

Synergist

Internal Oblique

External oblique

Antagonist

Shortened

crunched stomach, sucking in

Lengthened

Distended stomach

External Obliques

External Obliques

The obliques wrap around the trunk on each side to form our waists and join to the linea alba, a band of connective tissue running down the front of the abdomen.

Origin
    * Lowest 8 ribs

Insertion
    * Front 1/2 of the iliac crest
    * Abdominal Aponeurosis

Actions
    * Bilaterally bends the trunk to that side
    * and rotates the trunk to the other side
    * Compresses the abdomen and supports the abdominal viscera

Daily uses
    * Raking leaves

Synergist
Flexion

• Internal Oblique (Bilaterally)

Rotation

• Multifidi (To Opposite Side)
• Rotatores (To Opposite Side)

Lateral Flexion

• Spinalis (Unilaterally)
• Longissimus (Unilaterally)
• Iliocostalis (Unilaterally)
• Quadratus Lumborum (Unilaterally)
• External Oblique (To Same Side)
• Internal Oblique (To Same Side)
• Latissimus Dorsi

Antagonist

Extension

• Spinalis (Bilaterally)
• Longissimus (Bilaterally)
• Iliocostalis (Bilaterally)
• Multifidi
• Rotatores
• Semispinalis
• Quadratus Lumborum

Shortened

Bend to same side

Lengthened

Bend trunk to opposite side

Spinalis

Spinalis.

Erector spinae consists of lots of small fibres which are situated very close to the spine.


Origin
    * Nuchal Ligament
    * Cervical and Thoracic Spinous processes

Insertion
    * Cervical and Thoracic Spinous processes
    * Occipital Bone

Actions
    * Extension of the spine
    * Lateral flexion (side-bending) of the spine
    * Maintains correct curvature of the spine

Daily uses
    * Maintaining good posture

Synergist
Extension
    * Longissimus (Bilaterally)
    * Iliocostalis (Bilaterally)
Lateral Flexion
    * Multifidi
    * Rotatores
    * Semispinalis
    * Quadratus Lumborum

Antagonist
Extension
    * Rectus Abdominus
    * External Oblique (Bilaterally)
    * Internal Oblique (Bilaterally)

Shortened
Doing the bridge pose

Lengthened
Arching back

Longisimus

Longisimus

Erector spinae consists of lots of small fibres which are situated very close to the spine.


Origin

•   Thoracolumbar aponeurosis
•   Lumbar and Thoracic Transverse processes

Insertion

• Cervical transverse processes
• Thoracic transverse processes
• Mastoid processes

Actions

• Extension of the spine
• Lateral flexion (side-bending) of the spine
• Maintains correct curvature of the spine

Daily uses

• Maintaining good posture

Synergist
Extension

• Spinalis (Bilaterally)
• Iliocostalis (Bilaterally)

Lateral Flexion

• Multifidi
• Rotatores
• Semispinalis
• Quadratus Lumborum

Antagonist

• Extension

• Rectus Abdominus
• External Oblique (Bilaterally)
• Internal Oblique (Bilaterally)

Shortened

• Doing the bridge pose

Lengthened

• Arching back

Iliocostalis (lateral)

Iliocostalis (lateral)

Erector spinae consists of lots of small fibres which are situated very close to the spine.

Origin

•   Thoracolumbar aponeurosis
•   Posterior Ribs

Insertion

• Cervical transverse processes
• Posterior of ribs

Actions

• Extension of the spine
• Lateral flexion (side-bending) of the spine
• Maintains correct curvature of the spine

Daily uses

• Maintaining good posture

Synergist
Extension

• Longissimus (Bilaterally)
• Spinalis (Bilaterally)

Lateral Flexion

• Multifidi
• Rotatores
• Semispinalis
• Quadratus Lumborum

Antagonist
Extension

• Rectus Abdominus
• External Oblique (Bilaterally)
• Internal Oblique (Bilaterally)

Shortened

• Doing the bridge pose

Lengthened

• Arching back

Diaphragm

Diaphragm

Origin

• Costal attachment: Inner surface of lower 6 ribs
• Lumbar attachment: Upper 2-3 lumbar vertebrae
• Sternal attachment: Inner part of xyphoid process

Insertion

• Central Tendon

Actions

• Draws down the central tendon of diaphragm and increases thoracic cavity volume

Synergist

• External intercostals

• pectoralis minor

   

• scalenes
• sternocleidomastoid

Antagonist
Compresses the thorax

• internal intercostals

Shortened

• Exhale

Lengthened

• Inhale