Back Muscles + Osteology

go over Back Anatomy slides 47, 62

1. Trapezius action (4)

upward scapula rotation (elevates, retracts, and depresses scapula), upward rotation of glenoid fossa

2. Trapezius origin (3)

medial 1/3 of superior nuchal line, external occipital pertuberance, nuchal ligament

3. Trapezius insertion (3)

scapular spine and acromion process, lateral 1/3 of clavicle

4. Trapezius innervation (2)

cranial nerve XI (CN XI) – motor; C3-C4 (proprioception)

5. Trapezius blood supply

superficial transverse cervical artery

6. Latissimus dorsi actions (3)

adducts, extends, and medially rotates arm. Raises body toward arm during climbing

7. Latissimus dorsi origin (4)

6 inferior thoracic vertebrae (T6-T12) spinous process, thoracocolumbar fascia, iliac crest, inferior 3-4 ribs (ribs 8 or 9 – 12)

8. Latissimus dorsi insertion

floor of intertubucula

r sulcus of humerus

9. Latissimus dorsi innervation

thoracodorsal nerve

10. Latissimus dorsi blood supply

thoracodorsal artery

11. Layer 1 of back muscle includes (2)

trapezius, latissimus dorsi

12. Triangle of auscultation sides (3)

inferior border of trapezius (medial), superior border of latissimus dorsi (inferior), rhomboid major (lateral)

13. Lumbar triangle (of petit) sides (3)

latissimus dorsi lateral border (medial), iliac crest (inferior), external oblique’s posterior border (lateral)

14. Layer 2 of back muscle includes (3)

levator scapulae, rhomboid minor, rhomboid major

15. Superficial back layers

trapezius, latissimus dorsi, rhomboid minor, rhomboid major, levator scapulae, serratus posterior superior, serratus posterior inferior

16. Rhomboid minor actions

scapular retraction and downward rotation of glenoid fossa

17. Rhomboid minor origin (2)

nuchal ligament, spinous process of C7 – T1

18. Rhomboid minor insertions

medial border of scapula (similar to rhomboid major)

19. Rhomboid major AND minor innervation

dorsal scapular nerve

20. Rhomboid major AND minor blood supply

deep branch of transverse cervical artery

21. Rhomboid major origin

spinous process T2 – T5

22. Rhomboid major insertion

medial border of scapula (similar to rhomboid minor)

23. Rhomboid major and minor actions (alone)

scapular retraction and downward rotation of glenoid fossa

24. Rhomboid major and minor actions (with levator scapulae)

downward rotation of glenoid fossa

25. Levator scapulae actions (alone)

scapular elevation

26. Levator scapulae actions (with rhomboid maj and min)

downward rotation of glenoid fossa

27. Levator scapulae innervation

dorsal scapular nerve

28. Levator scapulae blood supply

deep branch of transverse cervical artery

29. Layer 3 of back muscle includes (2)

serratus posterior superior, serratus posterior inferior

30. Serratus posterior superior origin

spinous process of C7 – T3

31. Serratus posterior superior insertion

superior border of ribs 2-5

32. Serratus posterior inferior origin

spinous process T11 – L2

33. Serratus posterior inferior insertion

inferior border of ribs 9-12

34. Serratus posterior INFERIOR AND SUPERIOR action (2)

breathing assist, proprioception

35. Serratus posterior SUPERIOR action

expand lungs by pulling on ribs

36. Serratus posterior INFERIOR action

pull down on diaphragm

37. Serratus posterior inferior/superior innervation

intercostal nerves (ventral rami)

38. Serratus posterior inferior/superior blood supply

intercostal artery

39. Layer 4 of back muscle includes (5)

erector spinae + splenius… (iliocostalis, longissimus, spinalis) + (splenius capitis, splenius cervicis)

40. Splenius components (2)

splenius capitis, splenius cervicis

41. Splenius capitis origin(2)

nuchal ligament, C7 – T3 spinous process

42. Splenius capitis insertion (2)

mastoid process of temporal bone, lateral process of nuchal line

43. Splenius capitis AND splenius cervicis actions (3)

b/l neck extension, unilateral neck lateral rotation and unilateral ipsilateral side bending

44. Splenius capitis AND splenius cervicis innervation

spinal nerves dorsal rami

45. Splenius capitis AND splenius cervicis blood supply (2)

descending branch of occipital artery, deep cervical artery

46. which splenius muscle sits superiorly to the other?

splenius CAPITIS is superior to splenius CERVICIS

47. iliocostalis action (2)

b/l spine extension, unilateral spine side bending

48. iliocostalis innervation

dorsal rami

49. longissimus action (2)

b/l spine and head extension, unilateral spine and head side bending

50. spinalis action (2)

b/l spine extension, unilateral spine side bending (not as well as longissimus and iliocostalis tho)

51. Erector spinae actions

extend spine, laterally bend spine to same side as muscle belly

52. Erector spinae components (3)

iliocostalis, longissimus, spinalis (ILS – I love spanking – lateral to medial)

53. Layer 5 (Transversospinal) of back muscles include (3)

transversospinal (semispinalis, multifudus, rotatores – long to short)

54. How are transversospinal muscles attached?

from transverse process below to spinous process above

55. Transversospinal muscles action

rotate spine to opposite side (contralaterally)

56. Semispinalis origin

transverse process below

57. Semispinalis insertion

spinous process above

58. Semispinalis capitis origin

transverse process of upperthoracic vertebrae

59. Semispinalis capitis insertion

superior nuchal line

60. Semispinalis action

rotation toward contralateral side

61. Semispinalis capitis action

head extension

62. Semispinalis innervation

dorsal rami spinal nerves

63. Multifidus origin

transverse process below

64. Multifidus insertion

spinous process above

65. Multifidus actions

rotation toward contralateral side (like semispinalis)

66. Rotatores origin

transverse processes

67. Rotatores insertion

spinous processes

68. Rotatores action

rotation toward contralateral side

69. Rotatores innervation

dorsal rami of spinal nerves

70. Semispinalis is the ___ transversospinal muscle spanning ____ segments

semispinalis is the longest transversospinal muscle, spanning 4-6 segments

71. Multifidus is the ____ transversospinal muscle spanning ____ segments

multifidus is the 2nd longest transversospinal muscle spanning 2-4 segments

72. Rotatores is the ___ transversospinal muscle spanning ____ segments

rotatores is the shortest transversospinal muscle spanning 1-2 segment

73. Transversopinales actions

rotate spine toward contralateral side

74. Transversospinalis segments (3)

semispinalis, multifidus, rotatores

75. Epaxial muscles

‘intrinsic’ / deep back muscles, innervated by dorsal rami nn.

76. Hypaxial muscles

‘extrinsic’ / superficial back muscles, innervated by ventral rami nn.

77. Layer 6 (intersegmental) back muscles include (3)

intersegmental muscles: interspinalis, intertransversarii, and levator costarum

78. Interspinales origin

spinous process above insertion

79. Interspinales insertion

spinous process below origin

80. Interspinales action

spine stabilization and proprioception

81. Interspinales innervation

dorsal rami spinal nerve

82. Interspinales blood supply

branches of intercostal and lumbar artery

83. Intertransversarii origin

transverse process BELOW insertion

84. Intertransversarii insertion

transverse process ABOVE origin

85. Intertransversarii action

spine stabilization and proprioception

86. Intertransversarii blood supply

branches of intercostal artery and lumbar artery

87. Levator costarum origin

transverse process above insertion

88. Levator costarum insertion

rib medial to angle below origin

89. Levator costarum action (3)

rib elevation, proprioception, stabilization

90. Levator costarum blood supply

branches of intercostal and lumbar artery

91. Atlanto-occipital joint action

“yes” movement aka head extension and flexion

92. Atlanto-axial joint movement

“No” movement aka head rotation

93. Suboccipital triangle muscles include (4)

rectus capitis posterior minor, rectus capitis posterior major, obliquus capitis superior, obliquus capitis inferior

94. Suboccipital triangle location

found just deep to semispinalis capitis

95. suboccipital triangle muscle components (4)

rectus capitis posterior minor, rectus capitis posterior major, obliquus capitis superior, obliquus capitis inferior

96. suboccipital triangle innervation

suboccipital nerve

97. suboccipital triangle blood supply (2)

vertebral artery, descending branch of occipital artery

98. rectus capitis posterior minor origin

tubercle of C1 atlas posterior arch

99. rectus capitis posterior minor insertion

inferior nuchal line

100. recus capitis posterior minor action

head extension