Back Muscles

Splenius Muscles

Erector Spinae

Transversospinalis Muscles

• Proximal Attachment: Ligamentum nuchae and SPs of C7-T3
• Distal Attachment: Superior border of ribs 2-5
• Innervation: T2-T5 (intercostals)
• Main Actions: Elevates ribs

• Proximal Attachment: SPs of T11-L2
• Distal Attachment: Inferior border of ribs 9-12
• Innervation: VR T9-T12
• Main Actions: Depresses ribs

• Proximal Attachment: Nuchal ligament, SPs of C7-T3
• Distal Attachment: Mastoid process and lateral third of superior nuchal line
• Innervation: Dorsal rami of middle cervical nerves
• Main Actions: Bilaterally: extends head. Unilaterally: laterally flexes and rotates face to same side

• Proximal Attachment: SPs of T3-T6
• Distal Attachment: TPs of C1-C3 (sometimes C4)
• Innervation: Dorsal rami of lower cervical nerves
• Main Actions: Bilaterally: extends neck. Unilaterally: laterally flaxes and rotates neck toward same side

• Proximal Attachment: Posterior sacrum, iliac crest, and SPs of lower lumbar and sacral vertebrae
• Distal Attachment: Angles of lower ribs and cervical TPs
• Innervation: Dorsal rami of respective spinal nerves of each region
• Main Actions: Extends and laterally bends vertabral column and head

• Proximal Attachment: Posterior sacrum, iliac crest, and SPs of lower lumbar and sacral vertebrae
• Distal Attachment: Between tubercles and angles of ribs, TPs of thoracis and cervical vertebrae, mastoid process
• Innervation: Dorsal rami of respective spinal nerves of each region
• Main Actions: Extends and laterally bends vertabral column and head

• Proximal Attachment: Posterior sacrum, iliac crest, and SPs of lower lumbar and sacral vertebrae
• Distal Attachment: SPs of upper thoracic and midcervical vertebrae
• Innervation: Dorsal rami of respective spinal nerves of each region
• Main Actions: Extends and laterally bends vertabral column and head

• Proximal Attachment: TPs of C4-T12
• Distal Attachment: SPs of cervical and thoracic region spanning 4-6 segments
• Innervation: Dorsal rami of respective spinal nerves of each region
• Main Actions: Extends head, neck, and thorax and rotates them to opposite side. *Contralateral rotation*

• Proximal Attachment: TPs of C4-T12
• Distal Attachment: Occipital bone and SPs of cervical region spanning 4-6 segments
• Innervation: Dorsal rami of respective spinal nerves of each region
• Main Actions: Extends head, neck, and thorax and rotates them to opposite side. *Contralateral rotation*

• Proximal Attachment: Sacrum, Ilium, and TPs of T1-T12 and articular processes of C4-C7
• Distal Attachment: SPs of vertebrae above, spanning 2-4 segments
• Innervation: Dorsal rami of respective spinal nerves of each region
• Main Actions: Stabilizes spine during local movements

• Proximald Attchment: TPs
• Distal Attachment: Lamina and TP or SP above, spanning 1-2 segments
• Innervation: Dorsal rami of respective spinal nerves of each region
• Main Actions: stabilize, extend, and rotate spine

• Proximal Attchment: Tips of TPs of C7 and T1-T11
• Distal Attachment: Between tubercle and angle of ribs
• Innervation: Dorsal rami of C8-T11
• Main Actions: Elevates ribs, assisting respiration; assist with lateral flexion of vertebral column

• Proximal Attachment: Spine of axis
• Distal Attachment: Lateral inferior nuchal line
• Innervation: Suboccipital nerve (C1)
• Main Actions: Extends head and rotates to same side

• Proximal Attchment: Tubercle of posterior arch of atlas
• Distal Attchement: Median inferior nuchal line
• Innervation: Suboccipital nerver (C1)
• Main Actions: Extends head

• Proximal Attachment: TP of atlas
• Distal Attachment: Occipital bone
• Innervation: Suboccipital nerve (C1)
• Main Actions: Extends head and bends it laterally

• Proximal Attachment: Spine of axis
• Distal Attchment: TP of atlas
• Innervation: Suboccipital nerve (C1)
• Main Actions: Rotates atlas to turn face to same side

Runs over SPs of cervical vertabrae to the external occipital protuberance and medial nuchal line

Runs over SPs of thoracic and lumber vertebrae

Extends superolaterally from SPs of thoracic and lumbar regions