Back of Trunk Muscles PDF
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Uploaded by LowRiskSteelDrums
Wasit University, College of Medicine
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Summary
This document provides information about the back muscles and shoulder muscles in the human body. It details their origins, insertions, and actions, along with diagrams showing their location and interconnections. The document is likely aimed at students studying human anatomy or physiology.
Full Transcript
Back of Trunk Posterior Axio-appendicular The Back Muscles Muscles (Posterior Shoulder Muscles) are divided into three groups: 1) Superficial (Extrinsic) Muscles: Trapezius & Latissimus dorsi. 2) Deep (Extrinsic) Muscles: Levator scapulae & Rhomboi...
Back of Trunk Posterior Axio-appendicular The Back Muscles Muscles (Posterior Shoulder Muscles) are divided into three groups: 1) Superficial (Extrinsic) Muscles: Trapezius & Latissimus dorsi. 2) Deep (Extrinsic) Muscles: Levator scapulae & Rhomboids. 3) Scapulo-humeral (Intrinsic) Muscles: Deltoid, Teres Major & Rotator Cuff muscles Origin: 1-Medial third of Trapezi us superior nuchal line2-external occipital protuberance3- nuchal ligament 4-spinous processes of C7-T12 vertebrae Insertion: 1Lateral third of clavicle2 acromion and 3spine of scapula Accessory N. + C3,4 Act on scapula Latissimus dorsi Origin: 1- Spinous processes of inferior 6 thoracic vertebrae, 2-thoracolumbar fascia, 3-iliac crest, 4-inferior 3 or 4 ribs Insertion: Floor of intertubercular groove of humerus. NS: Thoracodorsal nerve (C6, C7, C8). Action: 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 Origin: Rhomboids 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 Origin: Lateral third of Deltoid 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 Four Intrinsic Rotator Cuff shoulder muscles Muscles (Supraspinatus, Infraspinatus, Teres minor and Subscapularis) They rotate&stabilize the shoulder J 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 arm Middle part of Inferior facet of Teres Minor lateral border of greater tubercle Axillary nerve scapula 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 THANK YOU
