The deltoid muscle (also known as deltoideus muscle) is the largest of the shoulder muscles. The muscle is composed of three heads (clavicular, acromial and spinous), although electromyography suggests that there are at least seven control regions that could act independently .
- origin: lateral 1/3 of the clavicle, acromion, lateral 2/3 of the scapula spine
- insertion: deltoid tuberosity of the humerus
- innervation: axillary nerve (C5-6)
- arterial supply :