Back of Trunk Muscles PDF

Back of Trunk By Dr. Muhamad Saeed Sulaivany  Posterior Axioa-ppendicular Muscles The Back Muscles (Posterior Shoulder Muscles) are divided into three groups: ) Superficial (Extrinsic) Muscles: Trapezius & Latissimus dorsi. ) Deep...

Back of Trunk By Dr. Muhamad Saeed Sulaivany  Posterior Axioa-ppendicular Muscles The Back Muscles (Posterior Shoulder Muscles) are divided into three groups: ) Superficial (Extrinsic) Muscles: Trapezius & Latissimus dorsi. ) Deep (Extrinsic) Muscles: Levator scapulae & Rhomboids. ) Scapulo-humeral (Intrinsic) Muscles: Deltoid, Teres Major & Rotator Cuff muscles  Trapezius Origin: Medial third of superior nuchal line; external occipital protuberance; nuchal ligament; spinous processes of C7-T12 vertebrae Insertion: Lateral third of clavicle; acromion and spine of scapula Accessory N. + C3,4  Latissimus dorsi Origin: Spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs Insertion: Floor of intertubercular groove of humerus Thoracodorsal nerve (C6, C7, C8) Extends, adducts, and medially rotates humerus  Levator Scapulae Origin: transverse processes of C1-C4 vertebrae Insertion: Medial border of scapula superior to root of spine Dorsal Scapular N. (C5) Elevate medial border of scapula  Rhomboids Origin: Minor: nuchal ligament; spinous processes of C7 and T1 vertebrae Major: spinous processes of T2-T5 vertebrae Insertion: Minor: smooth triangular area at medial end of scapular spine Major: medial border of scapula from level of spine to inferior angle Dorsal Scapular N. Retraction and medial rotation of scapula  Deltoid Origin: Lateral third of clavicle; acromion and spine of scapula Insertion: Deltoid tuberosity of humerus Axillary nerve (C5, C6) Anterior part: flexes and medially rotates arm Middle part: abducts arm Posterior part: extends and laterally rotates arm Teres Major Origin: Posterior surface of inferior angle of scapula Insertion: Medial lip of intertubercular groove of humerus Lower subscapular nerve (C5, C6) Adducts and medially rotates arm  Rotator Cuff Muscles Four Intrinsic shoulder muscles (Supraspinatus, Infraspinatus, Teres minor and Subscapularis) They rotate and stabilize the shoulder joint  Muscle Origin Insertion Innervation Action Initiates and Superior facet of Suprascapular Supraspinous assists deltoid in Supraspinatus greater tubercle nerve (C4, C5, fossa of scapula abduction of of humerus C6) arm Middle facet of Infraspinous Suprascapular Infraspinatus greater tubercle fossa of scapula nerve (C5, C6) of humerus Laterally rotate Axillary N. arm Middle part of Inferior facet of Inferior facet of Teres Minor lateral border of greater tubercle greater tubercle scapula of humerus of humerus Subscapular Upper and lower fossa (most of Lesser tubercle subscapular Medially rotates Subscapularis anterior surface of humerus nerves (C5, C6, and adduct arm of scapula) C7) Disposition of Rotator cuff