Muscles Flashcards
External Oblique
> P: Superficial-most of antero-lateral wall with fibres running infero-medially
O: External surfaces of lower 8 ribs (+cc)
I: Anterior 2/3 of iliac crest
: Pubic tubercle (ASIS - pubic tubercle is inguinal ligament)
: Line alba via rectus sheath
A: Bilateral - flexion of thoracic spine (+lumbar)
- posterior pelvic tilt
: Ipsilateral - side flexion
: contralateral - rotation
Internal Oblique
> P: Middle muscle of antero-lateral wall with fibres running supero-medially
O: Lower border of 10th-12th ribs (+cc)
: Linea alba via rectus sheath
: Pectin pubis via conjoint tendon (arch on superior ramus of pubis+pubic tubercle)
I: Lateral 2/3 of inguinal ligament
: Anterior 2/3 of iliac crest
: TLF
A: Bilateral: flexion of trunk (thoracic + lumbar spine)
: posterior pelvic tilt
: Ipsilateral: side flexion
: rotation
Transversus Abdominis
> P: Deepest muscle of antero-lateral wall with fibres running horizontally
O: Internal surfaces of 7th-12th costal cartilages
: TLF
: Iliac crest
: Lateral 1/3 of inguinal ligament
I: Linea alba via rectus sheath
: Pectin pubis via conjoint tendon
A: Increase intra-abdominal pressure
: Stability
Rectus Abdominis
> P: Superficial aspect of anterior abdominal wall
> O: Xiphoid process
: 5th-7th costal cartilages
> I: Pubic symphysis + crest
> A: Bilateral: trunk flexion
: posterior pelvic tilt
: Ipsilateral: side flexion
: Contralateral: rotationInterspinales
> P: Deep muscles of back - ‘transversospinales’ group
O/I: Between spinous processes of adjacent vertebrae
A: Extension of spine (segmental level)
: stability
*Underdeveloped in thoracic region due to limited flexion + extension
Intertransversarii
> P: Transversospinales group (deep muscles of spine)
O/I: Between transverse processes of adjacent vertebrae
A: Ipsilateral side flexion (segmental level)
: stability
Levatores Costarum
> P: Transversospinales (deep muscles of spine)
O: TP of C7-T11
I: Superior border of rib one or two ribs below (no. of attachments dependent on level of spine)
A: Elevates ribs
: Rotation of thoracic spine
: Side flexion of thoracic spine
Rotatores
> P: Transversospinales (deep muscles of back)
O/I: SP to TP (1 level below = brevis, 2 levels = longus)
A: Bilateral: Extension
: Stability
: Contralateral: Rotation
*Most pronounced within thoracic region
Multifidus
> P: Deep muscle of back running length of spine (superficial to interspinales etc.)
Lumborum
> O: Posterior Sacrum + PSIS (+post. sacro-iliac ligs)
: Mamillary processes of lumbar vertebrae
> I: Spinous processes 1-4 levels above (depends on layer of muscle)
> A: Stability
Thoracis
> O: Transverse processes of thoracic region
> I: Spinous processes 1-4 levels above (layer dependent)
> A: Stability
Semispinalis
> P: Superficial to multifidus, deep to erector spinae
Thoracis
> O: TP of T6-10
> I: SP of T4-C6
*made up of 5/6 fascicles which bridge over ~6 vertebral units
> A: Bilateral: Extension
: Unilateral: assists rotation
Iliocostalis
> P: Most lateral erector spinae muscle, superficial to multifidus but deep to lats + traps
Lumborum
> O: TLF
> I: TP of Lumbar vertebrae
: Rib angles of 5-12
Thoracis
> O: Rib angles of 7-12
> I: Rib angles of 1-6
: TP of C7
Cervicis
> O: Rib angles of 3-6
> I: TP of C4-6
> A: Bilateral: extension
: Unilateral: side flexion
: rotation
Longissimus
> P: Middle Erector spinae muscle
Thoracis
> O: TLF
> I: Transverse processes of Lumbar + Thoracic vertebrae
* Cervicis and capitis as ascend spine
> A: Bilateral: Extension of spine
: Anterior pelvic tilt
: Unilateral: side flexion
: rotation
Spinalis
> P: most medial of erector spinae group
Thoracis
> O: TLF
> I : Spinous processes of L2 - T1
\+Cervicis and Capitis as ascend
> A: Bilateral: Extension of spine
: Anterior pelvic tilt
: Unilateral: side flexion
: rotation
+ Superficial layer
> Serratus posterior inferior > Serratus posterior superior > Rhomboids > Latissimus Dorsi > Trapezius
