Sacrum and Coccyx Anatomy
Deltoid Muscle – Anterior and Middle Heads
The Deltoid muscle (derived its name from the Greek letter delta) is a large, triangular muscle occupying the upper arm and the shoulder giving it this rounded shape. The deltoid consists three sets of fibers: anterior, middle, and posterior.
Attachments of Deltoid Muscle: Origin & Insertion
Origin: (proximal attachments)
a. Anterior (clavicular) head: anterior surface of the lateral clavicle.
b. Middle (acromial) head: acromion process and spine of the scapula.
Insertion: (distal attachments)
a. Deltoid tuberosity of the humerus.
Actions of Deltoid Muscle: