Muscles of Pectoral Region & Back PDF

## Muscles of the Pectoral Region ### Pectoralis Major | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| | Sternocostal head: - Anterior surface of sternum - Front of the upper 6 costal cartilages - Aponeurosis of external abdominal oblique muscle Clavicular head: - Anterial surfa...

## Muscles of the Pectoral Region ### Pectoralis Major | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| | Sternocostal head: - Anterior surface of sternum - Front of the upper 6 costal cartilages - Aponeurosis of external abdominal oblique muscle Clavicular head: - Anterial surface of the medial half of the clavicle | Lateral lip of the licepital groove | Adduction -Medial Rotation - Clavicular head: ✓ Flexion - Sterno costal head: ✓Extends flexedarm | Lateral and Medial Rectoral Nerves. | ### Pectoralis Minor | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| | Outer surfaces of 3rd 4th 5th ribs | Anterior surface of the medial border of Coracoid Process | -Protraction of shoulder girdle - Depression of shoulder - Forced inspiration (Scapula fixed) | Medial Pectoral nerve | ### Subclarius | Origin | Insertion | Action | Nerve | |---|---|---|---| | Upper surface of 1st costo-chondral junction. | A groove on the inferior surface of the middle third of the clavicle | Steadies the clavicle | Nerve to subclavius. (C5) | ### Serratus Anterior | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| ## Muscles of the Back ### Trapezius | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| | -Back of the skull - External occipital protuberance - Medial third of the Superior nuchal line -Back of the neck - From the ligamentum nuchal and spine of 7th vertebra -Back of Thorax - Spines of All thoracic vertebrae and ther supra spinous ligaments | V-shaped Insertion - Upper fibers: posterior border of lateral third of the clavicle - Middle fibers: medial border of acromion process - Upper lip of Crest of spine of scapula - Lower fibers: rough tubercle on the crest of spine of scapula | As a whole: maintain shalder level - Upper: elevation - Upper and Cover: Upward rotation of scapula - Midde: retraction of scapula (bring the shoulder) backward | Motor: Spinal root of accessory nerve Sensory: C3, C4 | ### Latissmus Dorsi | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| | -Lower 6 thoracic - Thoracolumbar fascia - Posterior part of outer lip of iliac crest. - Outer surface of lower 4 ribs - Dorsal aspect of inferior angle scapula | Floor of bicepital groove | Addvetion - Extension - Medial rotation - Accessory muscle of forced expiration | Nerve to latissmus dorsi (thorace dorsal) nerve | ### Levator Scapulae | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| | Transverse process of upper 4 cervical | Dorsal surface of medial border above root of spine. | Scapula: - Elevation -Refraction - Downward rotation | Motor: Nerve to rhomboids (C5) (dorsal scapular) nerve Sensory: C3, CA | ### Rhomboideus Minor | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| | Nuchal ligament -C7, T1 spines | Dorsal surface of medial border scapula | Scapula: - Retraction -Dameward rotation | Nerve to rhomboids | ### Rhomboideus Major | Origin | Insertion | Action | Nerve Supply | |---|---|---|---| | T2, T3, T4, T5 and their supraspinous ligaments | Dorsal surface of medial border scapula -Below root of spine | Scapula: - Retraction - Down ward rotation | Nerve to rhomboids | ### Applied Anatomy and Clinical Importance Trapezivs: Paralysis leads to shoulder drop. ### Sports related to muscles Latismuss dorsi: Swimming, rowing, climbing