The muscles of the pectoral girdle are essential for stabilizing and positioning the shoulder joint.
They facilitate the movements of the arm.
Divided into two groups: anterior muscles (front of the thorax) and posterior muscles (back of the thorax).
Location: Anterior thorax.
Function: Stabilizes the clavicle by pushing it downward (depression).
Origin: First rib.
Insertion: Underside of the clavicle.
Location: Anterior thorax.
Function: Rotates the shoulder forward (important for throwing) and assists with inhalation.
Movement: Affects the scapula by moving it down; elevates ribs.
Origin: Anterior surfaces of ribs 2-4 or 3-5.
Insertion: Coracoid process of the scapula.
Location: Anterior thorax.
Function: Moves the arm from the side of the body to the front; assists with inhalation.
Movement: Protracts scapula and elevates ribs.
Origin: Muscle slips from ribs 1-8 or 1-9.
Insertion: Anterior surface of the scapula's vertebral border.
Location: Posterior thorax.
Function: Elevates shoulders (shrugging), pulls shoulder blades together, and tilts head backward.
Movement: Affects scapula and cervical spine by retracting, elevating, and extending the spine.
Origin: Skull and vertebral column.
Insertion: Acromion and spine of the scapula; clavicle.
Location: Posterior thorax.
Function: Stabilizes shoulder blade (scapula) during pectoral girdle movement.
Movement: Retracts and rotates scapula downward.
Origin: Thoracic vertebrae (T2-T5).
Insertion: Medial border of the scapula.
Location: Posterior thorax.
Function: Also stabilizes shoulder blade during movement.
Movement: Retracts and rotates scapula downward.
Origin: Cervical and thoracic vertebrae (C7 and T1).
Insertion: Medial border of the scapula.
Provides an overview of the primary muscles, their movements, origins, and insertions.
Highlights their roles in the stabilization and movement of the shoulder.
These muscles provide vital stability to the pectoral girdle.
They enable a wide range of movements in the arm and shoulder, facilitating various physical activities and tasks.
Recommended video: "Shoulder (Pectoral) Girdle - Muscles and Movements" available through the provided link.