Muscle of the Month: Anterior Deltoids
Location: The anterior deltoid is one of three muscles that lies over the glenohumeral joint (the shoulder joint). The anterior deltoid is located on the front third of the shoulder and is the most forward facing of the 3 deltoid muscles.
Attachments (where the muscle starts and ends):
Origin: Anterior, lateral third of the clavicle (the outer third of the front side of the collarbone)
Insertion: Deltoid tuberosity of the humerus (The top of your upper arm bone)
The Anterior Deltoid is responsible for abduction of the shoulder, the action of moving your arm straight out to the side and up overhead. It is also responsible for flexion of the shoulder, lifting your arm straight out in front of you and up overhead. These are the two primary actions of the Anterior Deltoid, but it is also responsible for transverse flexion and internal rotation of the shoulder. Both of these actions move the arm toward the mid-line of the body when the shoulder is already in flexion. Internal rotation causes the shoulder head to roll inward.
Exercises that use this muscle:
- Front Raise
- Shoulder Press
- Arnold Press
Being the forward most muscle of the 3 deltoid muscles, the anterior deltoid is responsible for the majority of movement that happens in front of our bodies at the shoulder joint. It is active in most instances when we are holding an object in front of us, lifting overhead, or performing swinging or throwing motions. This particular muscle is used each day whether you are reaching for something in a cabinet or even just turning a doorknob! Maintaining strength of the anterior deltoid and flexibility and mobility of the shoulder joint is essential so that you can lift your arms overhead even as you progress into later stages of life!