Exam 1 Study Guide

Erector Spinae

Order medial to lateral from Spine:

Spine-Spinalis-Longissimus-Iliocostalis

Level: Superficial to Transversospinalis

ACTIONS (2)

Unilaterally: Laterally flex vertebral column to the same side 

Bilaterally: Extend the vertebral column

-Transversospinalis-

Multifidi & Rotatores

O: Multifidi: Posterior surface of the sacrum and transverse processes 

Rotatores: Transverse processes 

I: Spinous processes 

Multifidi: span 2-4 vertebrae from lumbar to cervical areas

Rotatores: span 1-2 vertebrae from lumbar to cervical areas

ACTIONS (2)

Unilaterally: Rotate the vertebral column to the opposite side 

Bilaterally: Extend the vertebral column

Splenius Capitis & Cervicis

O: Capitis: Inferior ligamentum nuchae and C-7 to T-4 spinous processes

Cervicis: T-3 to T-6 spinous processes

I: Capitis: Mastoid process and superior nuchal line 

Cervicis: Transverse processes of C-1 to C-3

ACTIONS (3)

Unilaterally: 

Rotate the head and neck to the same side 

Laterally flex the head and neck to the same side 

Bilaterally: 

Extend the head and neck

Suboccipitals

Level: Deep to all musculature of the head & neck

ACTIONS (3)

Rock/tilt the head back into extension 

Rotate the head to the same side 

Laterally flex the head to the same sid

Quadratus Lumborum

O: Posterior iliac crest

I: 12th rib and transverse processes of L1-4

ACTIONS (4)

Unilaterally: 

Laterally tilt (elevate) the pelvis 

Laterally flex the vertebral column to the same side 

Bilaterally: 

Assist to extend the vertebral column

Fix the last rib during forced inhalation and exhalation

Rectus Abdominis

O: Pubic crest, pubic symphysis

I: Cartilage of ribs 5-7 and xiphoid process

ACTIONS (2)

Flex the vertebral column 

Tilt pelvis posteriorly

External Oblique

O: Ribs 5-12

I: Anterior iliac crest, abdominal aponeurosis to linea alba

ACTIONS (4)

Unilaterally: Laterally flex vertebral column to the same side 

Rotate vertebral column to the OPPOSITE SIDE 

Bilaterally: Flex the vertebral column 

Compress abdominal contents

Internal Oblique

O: Inguinal ligament, iliac crest, and thoracolumbar fascia

I: Ribs 10-12, abdominal aponeurosis to linea alba

ACTIONS (4)

Unilaterally: Laterally flex vertebral column to the same side 

Rotate vertebral column to the SAME SIDE 

Bilaterally: Flex the vertebral column 

Compress abdominal contents

Transverse Abdominis

O: Inguinal ligament, iliac crest, thoracolumbar fascia, and ribs 7-12

I: Abdominal aponeurosis to linea alba

ACTIONS (1)

Compress abdominal contents

Diaphragm

O: Lower ribs, lumbar vertebrae, xiphoid process

I: Central tendon

ACTIONS (2)

Draw down the central tendon 

Increase the volume of the thoracic cavity during inhalation

Internal & External Intercostals

O: Inferior rib border above

I: Superior rib border below

ACTIONS (2)

External: inhalation

Internal: exhalation

Sternocleidomastoid (SCM)

O: Sternal head: Top of manubrium 

Clavicular head: Medial clavicle

I: Mastoid process of temporal bone and the lateral portion of superior nuchal line of occiput

ACTIONS (4)

Unilaterally: Laterally flex the head and neck to the same side
Rotate head and neck to the opposite side 

Bilaterally: Flex the neck 

Assist to elevate the ribcage during inhalation

Anterior Scalenes

O: C3-6 transverse processes 

I: 1^st rib

ACTIONS (4)

Unilaterally: With the ribs fixed, laterally flex the head and neck to the same side (All) 

Rotate head and neck to the opposite side (All) 

Bilaterally: 

Elevate the ribs during inhalation (All) 

Flex the head and neck (Anterior)

Middle Scalenes

O: C2-7 transverse processes 

I: 1^st rib

ACTIONS (4)

Unilaterally: With the ribs fixed, laterally flex the head and neck to the same side (All) 

Rotate head and neck to the opposite side (All) 

Bilaterally: 

Elevate the ribs during inhalation (All) 

Flex the head and neck (Anterior)

Posterior Scalenes

O: C6-7 transverse processes

I: 2^nd rib

ACTIONS (4)

Unilaterally: With the ribs fixed, laterally flex the head and neck to the same side (All) 

Rotate head and neck to the opposite side (All) 

Bilaterally: 

Elevate the ribs during inhalation (All) 

Flex the head and neck (Anterior)

Masseter

O: Zygomatic arch

I: Mandible

ACTIONS (2)

Elevate the mandible (TMJ) 

Protract the mandible (TMJ)

Temporalis

O: Temporal area

I: Mandible

ACTIONS (2)

Elevate the mandible (TMJ) 

Retract the mandible (TMJ)