Muscles of the Back and Craniocervical Regions: Intrinsic Muscles of the Back

Question 1

Erector Spinae Proximal Attachment

Answer 1

Via common tendon to the posterior iliac crest, sacrum, spinous processes of lumbar vertebrae, and supraspinous ligament

Question 2

Spinalis Distal Attachment

Answer 2

Fibers run upward to spinous processes of upper thoracic and cervical vertebrae and to the occiput

Question 3

Longissimus Distal Attachment

Answer 3

Fibers run upward to transverse processes of thoracic and cervical vertebrae and to the mastoid process

Question 4

Iliocostalis Distal Attachment

Answer 4

Fibers run upward to angles of the ribs in the thoracic region and transverse processes of lower cervical vertebrae

Question 5

Erector Spinae Innervation

Answer 5

Posterior rami of spinal nn. C3-L5

Question 6

Erector Spinae Action

Answer 6

Unilaterally: Laterally flexes the trunk/head/neck to the same side Rotates the head/neck to the same side Bilaterally: Extends the trunk/head/neck Anteriorly tilts pelvis

Question 7

Semispinalis Proximal Attachment

Answer 7

Transverse processes of C4-T12

Question 8

Semispinalis Distal Attachment

Answer 8

Fibers span 4-6 segments, running upward and medially to the occiput and spinous processes of thoracic and cervical vertebrae

Question 9

Multifidus Proximal Attachment

Answer 9

Posterior sacrum, PSIS, and transverse processes of L5-C4

Question 10

Multifidus Distal Attachment

Answer 10

Fibers span 2-4 segments, running upward and medially to spinous processes (best developed in the lumbosacral region)

Question 11

Rotatores Proximal Attachment

Answer 11

Transverse processes of L5-C4

Question 12

Rotatores Distal Attachment

Answer 12

Fibers span 1-2 segments, running upward and medially to spinous processes (best developed in the thoracic region)

Question 13

Transversospinales Innervation

Answer 13

Posterior rami of spinal nn. C1-S5

Question 14

Transversospinales Action

Answer 14

Unilaterally: Laterally flexes the trunk/head/neck to the same side Rotates the trunk/head/neck to the opposite side Bilaterally: Extends the trunk/head/neck Anteriorly tilts pelvis

Question 15

Quadratus Lumborum Proximal Attachment

Answer 15

Posterior iliac crest

Question 16

Quadratus Lumborum Distal Attachment

Answer 16

Rib 12 and transverse processes of L1-L4

Question 17

Quadratus Lumborum Innervation

Answer 17

Anterior rami of spinal nn. T12-L3

Question 18

Quadratus Lumborum Action

Answer 18

Unilaterally: Laterally flexes the trunk Elevates the pelvis Bilaterally: Extends the trunk Stabilizes the lumbar spine

Question 19

Iliacus Proximal Attachment

Answer 19

Iliac fossa and anterior ligaments of the lumbrosacral and sacroiliac joints

Question 20

Iliacus Distal Attachment

Answer 20

Lesser trochanter of the femur

Question 21

Iliacus Innervation

Answer 21

Femoral n. [*L1,*L2,L3]

Question 22

Iliacus Action

Answer 22

Flexes the hip Assists with: -Hip lateral rotation -Anterior pelvic tilt

Question 23

Psoas Major Proximal Attachment

Answer 23

Transverse processes, intervertebral discs, and adjacent bodies of T12-L5

Question 24

Psoas Major Distal Attachment

Answer 24

Lesser trochanter of the femur

Question 25

Psoas Major Innervation

Answer 25

Femoral n. [*L1,*L2,L3]

Question 26

Psoas Major Action

Answer 26

Flexes the hip Assists with: -Hip lateral rotation -Lumbar side flexion -Lumbar stabilization -Anterior pelvic tilt