Shoulder Muscles Flashcards
Learn attachments, actions and innervations
Pectoralis Major
Attachments, Actions, Innervation
Hint: 2 Heads
Origin:
Clavicular Head: Medial 1/2 of Clavicle
Sternocostal Head: Anterior surface of sternum, Costal Cartilages 1-6 Insertion: Intertubercular Sulcus
Actions:
Adduct + Med. Rotate Humerus, Draw Scapula Anterior + Inferior
Clavicular Head > Flex Humerus
Sternocostal Head > Extend Humerus
Nerve Supply:
Lateral + Medial Pectoral Nerves
Clavicular Head (C5, C6)
Sternocostal Head (C7, C8, T1)
Pectoralis Minor
Attachments, Action, Innervation
Origin: Ribs 3-5 near Costal Cartilages
Insertion: Coracoid Process
Action: Stabilise Scapular by Drawing Anteriorly + Inferiorly
Nerve Supply: Medial Pectoral Nerve (C8, T1)
Subclavius
Attachments, Action, Innervation
Origin: Junction of 1st Rib & 1st Costal Cartilages
Insertion: Inferior Surface of Middle 3rd Clavicle
Action: Anchors & Depreses Clavicle
Nerve Supply: Nerve to Subclavius (C5, C6)
Serratus Anterior
Attachments, Action, Innervation
Origin: Lateral Aspect Ribs 1-8
Insertion: Medial Border of Scapula
Action: Protract Scapula + Rotate Superiorly
Hold Scapula to Thorax
Nerve Supply: Long Thoracic Nerve (C5, C6, C7)
Trapezius
Attachments, Action, Innervation
Origin: Superior Nuchal Line, External Occipital Protuberance, Nuchal Ligament + SP’s C7 - T12
Insertion: Lateral 3rd Clavicle + Acromion & Spine of Scapula
Action:
Upper: Elevate Scapula
Middle: Retract Scapula
Lower: Depresses Scapula
Upper + Lower Combined Rotate Glenoid Cavity Superiorly
Nerve Supply: Accessory Nerve (XI) + C3-C4
Latissimus Dorsi
Attachments, Action, Innervation
Origin: SP’s of T7-T12, Thoracolumbar Fascia, Iliac Crest, Ribs 9-12
Insertion: Intertubercular Sulcus
Action: Extends, Adducts & Medially Rotates Humerus
Nerve Supply: Thoracodorsal Nerve (C6, C7, C8)
Levator Scapulae
Attachments, Action, Innervation
Origin: TP’s of C1 - C4
Insertion: Medial Border of Scapula
Action: Elevate Scapula + Rotate Scapula Inferiorly
Nerve Supply: Dorsal Scapula Nerve (C5), C3 and C4
Rhomboid Major
Attachments, Action, Innervation
Origin: T2-T5
Insertion: Medial Border of Scapula
Action: Retract Scapula + Rotate Glenoid Cavity Inferiorly
Nerve Supply: Dorsal Scapula Nerve (C4, C5)
Rhomboid Minor
Attachment, Action, Innervation
Origin: C7-T1
Insertion: Medial Border of Scapula
Action: Retracts Scapula + Rotates Glenoid Cavity Inferiorly
Nerve Supply: Dorsal Scapula Nerve (C4, C5)
Deltoid
Attachments, Action, Innervation
Origin: Lateral 3rd Clavicle, Acromion & Spine Of Scapula
Insertion: Deltoid Tuberosity of Humerus
Action:
Anterior: Flex + Medial Rotate Arm
Posterior: Extend + Lateral Rotate Arm
All Fibres Active in Abduction
Nerve Supply: Axillary Nerve (C5, C6)
Supraspinatus
Attachments, Action, Innervation
Origin: Supraspinous Fossa of Scapula
Insertion: Greater Tubercle of Humerus
Action: Initiates Abduction of Humerus (First 15°)
Maintains apposition of Head of Humerus and Gleniod Cavity during motion
Nerve Supply: Suprascapular Nerve (C4, C5, C6)
Infraspinatus
Attachements, Action, Innervation
Origin: Infraspinous Fossa of Scapula
Insertion: Greater Tubercle of Humerus
Action: Lat. Rotates Humerus + Maintains Apposition of Humerus and Glenoid Cavity During Motion
Nerve Supply: Suprascapular Nerve (C5, C6)
Teres Minor
Attachments, Action, Innervation
Origin: Lateral Border of Scapula
Insertion: Greater Tubercle of Humerus
Action: Lat. Rotates Humerus + Maintains Apposition of Humerus and Glenoid Cavity During Motion
Nerve Supply: Axillary Nerve (C5,C6)
Subscapularis
Attachments, Action, Innervation
Origin: Subscapular Fossa
Insertion: Lesser Tubercle of Humerus
Action: Med. Rotates Humerus + Maintains Apposition of Head of Humerus and Glenoid Cavity During Motion
Nerve Supply: Upper & Lower Subscapular Nerves (C5, C6, C7)
Teres Major
Attachments, Action, Innervation
Origin: Inferior Angle of Scapula
Insertion: Intertubercular Sulcus of Humerus
Action: Adduct + Med. Rotate Humerus
Nerve Supply: Lower Subscapular Nerve (C5, C6)
