click below
click below
Normal Size Small Size show me how
The Back Muscles
Origin, Insertion, Function, and Innervation
Name of Muscle | Origin | Insertion | Function | Innervation |
---|---|---|---|---|
Trapezius | Occipital bone, ligamentum nuchae, spines of C7 and T1-T12 | Clavicle, acromion and superior spine of scapula | Both elevates (upper fibers) and depresses (lower fibers) shoulder; retracts scapula; also extends head | Accessory n. |
Latissimus Dorsi | Spines of T6-T12, lumbar vertebrae, saccral crest, iliac crest, lower 3 or 4 ribs. | Intertubercular groove of humerus | Adducts, extends, and medially rotates arm | Thoracodorsal n. |
Rhomboideus Major | Spinous processes of T2-T5. | Vertebral border the scapular inferior to the spine. | Elevates and adducts scapula | Dorsal Scapular n. |
Rhomboideus Minor | Spinous processes of C7 and T1. | Vertebral border of the scapula superior to the spine. | Elevates and adducts scapula | Dorsal Scapular n. |
Thoracolumbar Fascia | covers deep muscles of back; attached medially to spines of vertebrae; inferiorly to ilium; provides for muscle attachments. | not listed | not listed | not listed |
Levator Scapula | Vertebrae - transverse processes of C1-C4 | Scapula - superior angle and medial border | Elevates and adducts scapula | Dorsal Scapular n. |
Splenius Capitis | Lower portion of ligamentum nuchae and spinous processes of C7 and T1-T4. | Mastoid process of temporal bone and occipital bone. | Extend neck and head | Dorsal rami of spinal nerves |
Semispinalis capitis | thorasic and cervical vertebrae occipital bone | occipital bone | extends head | dorsal rami |
Erector spinae-iliocostalis | from Ilium and ribs | Spinous processes six levels above | Extend trunk and vertebral column | Dorsal Rami |
Erector Spinae-Longissimus | from transverse processes of vertebrae | to transverse processes of vertebrae | Extend trunk and vertebral column | Dorsal Rami |
Erector Spinae-Spinalis | from spinous processes | to spinous processes | Extend trunk and vertebral column | Dorsal Rami |