Origin Insertion Nerve Action External Intercostal Inferior border of the ribs Insertion Superior border of the ribs below Nerve Intercostal nerve Action Elevates Ribs

Origin Insertion Nerve Action Splenius Capitis Mastoid process Nuchal ligament spinous process of C7 – T3 Insertion Mastoid process superior nuchal line Nerve Posterior rami of spinal nerves Action Unilaterally – laterally bend to side of active muscles Bilaterally – extend head and neck

Origin Insertion Nerve Action Erector Spinae Iliac crest Sacrum Supraspinous ligament Insertion Iliocostalis - angles of lower ribs and transverse process Longissimus - transverse process in thoracic and cervical regions , and to mastoid process Spinalis - spinous process thoracic region and to skull Nerve Posterior rami of spinal nerves Action Unilaterally – laterally bend vertebral column to side of active muscles Bilaterally – extend vertebral column and head

Origin Insertion Nerve Action Rhomboid Minor Nuchal ligament spinous process of C7 and T1 vertebrae Insertion Medial border of scapula from level of spine to inferior angle Nerve Dorsal scapular nerve Action Retracts scapula

Origin Insertion Nerve Action Deltoid Deltoid tuberosity of humerus Clavicular- lateral third of clavicle Acromial – Acromion Spinal – Spine of scapula Insertion Deltoid tuberosity of humerus Nerve Axillary nerve Action Clavicular – flexes and medially rotates arm Acromial – abducts arm Spinal – extends & laterally rotates arms

Origin Insertion Nerve Action Serratus Anterior Ribs 1 - 9 Anterior surface of the medial border of the scapula Nerve Long thoracic nerve C5-C7 Action Protracts scapula

Origin Insertion Nerve Action Teres Major Inferior angle of the scapula Insertion Lesser tubercle Nerve Lower subscapular Action Adduct and internally rotates humerus

Origin Insertion Nerve Action Trapezius Superior nuchal line External occipital protuberance Nuchal ligament Spinous process of C7-T12 Insertion Clavicle, acromion, spine of scapula Nerve Spinal accessory nerve Action Elevates, retracts, rotates scapula

Origin Insertion Nerve Action Rhomboid Major Spinous process of T2-T5 vertebrae Insertion Medial border of scapula from level of spine to inferior angle Nerve Dorsal scapular nerve Action Retracts scapula

Origin Insertion Nerve Action Internal Intercostal Inferior border of the ribs Insertion Superior border of the ribs below Nerve Intercostal nerve Action Depresses Ribs

Serratus Posterior Superior Origin Nuchal ligament Spinous process C7-T3 Insertion Ribs 2,3,4 Nerve 2nd-5th Intercostal nerves Action Elevates Ribs

Origin Insertion Nerve Action Quadratus lumborum 12th rib lumbar transverse process Insertion Iliolumbar ligament iliac crest Nerve Anterior rami of T12 & L1-L4 nerve Action Extends and laterally flexes (bends) vertebral column Hip hiker

Serratus Posterior Inferior Origin Spinous process T11-L2 Insertion Ribs 8-12 Nerve Anterior rami T9-T12 nerve Action Depresses Ribs

Origin Insertion Nerve Action Infraspinatus Infraspinatus fossa of scapula Insertion Greater tubercle of humerus Nerve Suprascapular nerve Action Laterally rotates arm

Origin Insertion Nerve Action Levator Scapulae Transverse process of C1-C4 Insertion Superior angle Nerve Dorsal scapular nerve Action Elevates scapula

Origin Insertion Nerve Action Splenius Cervicis Nuchal ligament spinous process of C7 – T3 Insertion Transverse process of C1-C3 Nerve Posterior rami of spinal nerves Action Unilaterally – laterally bend to side of active muscles Bilaterally – extend head and neck

Origin Insertion Nerve Action Latissimus Dorsi Bicipital groove Spinous process of T7-T12 Thoracolumbar fascia Iliac crest 3 or 4 ribs Insertion Bicipital groove Nerve Thoracodorsal nerve C6 Action Extends, adducts, medially rotates humerus

Origin Insertion Nerve Action Semispinalis Thoracic and cervical transverse process Insertion Run superomedially Attach to occipital bone and spinous process in thoracic & cervical regions Nerve Posterior rami of spinal nerves Action Unilaterally – rotate head and neck contralaterally Bilaterally – extend head and thoracic cervical regions. Stabilizes vertebrae

Origin Insertion Nerve Action Multifidus Sacrum and ilium Transverse process of T1-L5 Articular process of C4-C7 Insertion Run superomedially to spinous process Nerve Posterior rami of intercostal nerves Action Unilaterally – rotate head and neck contralaterally Bilaterally – extend head and thoracic cervical regions. Stabilizes vertebrae

Origin Insertion Nerve Action Rotatores Transverse process of vertebrae Insertion Run superomedially and attach to junction of lamina and transverse process Nerve Posterior rami of spinal nerves Action Stabilize vertebrae and assist with local extension and rotary movement