Back Muscles Flashcards
Iliocostalis Thoracis M.
A: Maintain erect posture and extend the Vertebral Column and head when working bilaterally; Laterally Flex the Vertebral Column when working unilaterally
N: Segmentally innervated by Posterior Rami of Spinal nerves
B: Intercostal Arteries
Splenius Cervicis M.
A: Extend the Neck when working bilaterally; Laterally
Flex the Neck and Rotate Face toward when working unilaterally
N: Posterior Rami C5-7
B: Occipital Artery
Serratus posterior inferior
A: Depress Ribs with forced expiration (primarily proprioceptive)
N: Anterior Rami T9-12
B: Intercostal artery
Longissimus Thoracis
A: Maintain erect posture and extend the Vertebral Column and
Head when working bilaterally; Laterally Flex the Vertebral Column when working unilaterally
N: Segmentally innervated by Posterior Rami of Spinal nerves
B: Posterior intercostal arteries and lumbar arteries
Serratus Posterior Superior M.
A: Elevate Ribs with forced inspiration (primarily
N: Intercostal N. (2-5)
B: Intercostal Arteries
Intertransversarii M. (best developed in Cervical and Lumbar Regions)
A: Laterally Flex spine
N: Posterior portion (Posterior Rami), Anterior portion (Anterior Rami)
B: Intercostal arteries and lumbar arteries
Rectus Capitis Posterior Major M. (medial border Suboccipital Triangle)
A: Extend Head, Rotate Face toward
N: Suboccipital N.
B: Muscular branches of the vertebral artery, descending branch of the occipital artery
Semispinalis Cervicis M.
A: Extend Spine and Rotate Spine away
N: Posterior Rami
B. Posterior intercostal arteries
Splenius Capitus M.
A: Extend the Neck when working bilaterally; Laterally T3(4) Nuchal Line of the Occipital B. Flex the Neck and Rotate Face toward when working unilaterally
N: Posterior Rami C3-5
B: Occipital Artery from external carotid
Latissimus Dorsi M.
A: Extend, ADduct and Medially Rotate the Humerus, rotate the glenoid cavity inferiorly
N: Thoracodorsal N. (C6-8)
B: Thoracodorsal artery
Levator Scapulae M.
A: Elevate scapula, Rotate the Glenoid Cavity inferiorly
and when the Scapula is fixed Extend and Laterally Flex the Neck
N: C3, 4, Dorsal Scapular N. (C5)
B: Dorsal Scapular Artery
Longissimus Cervicis
A: Maintain erect posture and extend the Vertebral Column and
Head when working bilaterally; Laterally Flex the Vertebral Column when working unilaterally
N: Segmentally innervated by Posterior Rami of Spinal nerves
B: Posterior intercostal arteries
Interspinalis M. (best developed in Cervical and Lumbar Regions)
A: Extend Spine
N: Posterior Rami
B: Posterior intercostal arteries, lumbar arteries, deep cervical branches of the costocervical trunck
Iliocostalis Cervicis
A: Maintain erect posture and extend the Vertebral Column and
Head when working bilaterally; Laterally Flex the Vertebral Column when working unilaterally
N: Segmentally innervated by Posterior Rami of Spinal nerves
B: Posterior intercostal arteries
Iliocostalis Lumborum M.
A: Maintain erect posture and extend the Vertebral Column and
Head when working bilaterally; Laterally Flex the Vertebral Column when working unilaterally
N: Segmentally innervated by Posterior Rami of Spinal nerves
B: Intercostal and lumbar arteries
Multifidus M. (3 or 4 spinal segments)
A: Extend Spine, Rotate the Spine away
N: Posterior Rami
B: Posterior intercostal and lumbar arteries, deep cervical branch of the costocervical trunk
Rhomboid Minor M.
N: Dorsal Scapular N. (C4, 5)
A: Retract and Elevate scapula, Rotate the Glenoid Cavity
B: Dorsal Scapular Artery
Obliquus Capitis Superior M. (lateral border Suboccipital
Triangle)
A: Extend and Laterally Flex Head
N: Suboccipital N.
B: Muscular branches of the vertebral artery, descending branch of the occipital artery
Levator Costarum Longus M.
A: Elevate ribs
N: Posterior Rami
B: Posterior instercostal arteries
Semispinalis Capitas M.
A: Extent Head, Rotate Face away
N: Posterior Rami
B: Posterior intercostal arteries
Trapezius M.
iNnervation: Motor: Spinal Accessory N. (CN XI)
Action: Whole muscle (Rotate point of the glenoid cavity superiorly, Retract the Scapula), Upper fibers (Elevate Scapula), Lower fibers (Depress Scapula) With the Scapula fixed the Upper fibers will Extend the Neck working bilaterally, Laterally Flex the Neck and Rotate the Face away when working unilaterally
Blood supply: Transverse cervical artery
Levator Costarum Brevis M.
A: Elevate ribs
N: Posterior Rami
B: Posterior instercostal arteries
Semispinalis Thoracis M.
A: Extend Spine and Rotate Spine away
N: Posterior Rami
B. Posterior intercostal arteries
Rhomboid Major M.
A: Retract and Elevate scapula, Rotate the Glenoid Cavity
inferiorly
N: Dorsal Scapular N. (C4, 5)
B: Dorsal scapular artery
Spinalis Cervicis M. (usually absent)
A: Maintain erect posture and extend the Vertebral Column and
Head when working bilaterally; Laterally Flex the Vertebral Column when working unilaterally
N: Segmentally innervated by Posterior Rami of Spinal nerves
B: Posterior intercostal arteries
Rectus Capitis Posterior Minor M. (medial border Suboccipital Triangle)
A: Extend Head
N: Suboccipital N.
B: Muscular branches of the vertebral artery, descending branch of the occipital artery
Rotatores Longus M. (extending 2 spinal segments)
A: Extend Spine, Rotate the Spine away (primarily proprioceptive)
N: Posterior Rami
B: Posterior intercostal arteries, lumbar arteries
Spinalis Thoracis M.
A: Maintain erect posture and extend the Vertebral Column and
Head when working bilaterally; Laterally Flex the Vertebral Column when working unilaterally
N: Segmentally innervated by Posterior Rami of Spinal nerves
B: Posterior intercostal arteries
Rotatores Brevis M. (extending to adjacent spinal segment)
A: Extend Spine, Rotate the Spine away (primarily proprioceptive)
N: Posterior Rami
B: Posterior intercostal arteries, lumbar arteries
Longissimus Capitis M.
A: Maintain erect posture and extend the Vertebral Column and
Head when working bilaterally; Laterally Flex the Vertebral Column when working unilaterally
N: Segmentally innervated by Posterior Rami of Spinal nerves
B: Posterior intercostal arteries
Obliquus Capitis Inferior M (inferior border Suboccipital Triangle)
A: Rotate Face toward
N: Suboccipital N.
B: Muscular branches of the vertebral artery, descending branch of the occipital artery
