The three main muscles of the shoulder are the deltoids, which are further broken down into three parts.
The Deltoid Muscles
The deltoid muscle is the primary muscle group responsible for shoulder movement. It is comprised of three distinct heads, each with its own function:
| Muscle Name | Function |
|---|---|
| Anterior Deltoids | Helps move the arm forward and connects to the clavicle (collarbone). |
| Lateral Deltoids | Assists in moving the arm away from the body, as well as up and down. |
| Posterior Deltoids | Facilitates the movement of the arm backward. |
Specific Roles of Each Deltoid Head
- Anterior Deltoids: Located at the front of the shoulder, these are crucial for actions like lifting your arm in front of you, pushing, and internal rotation of the arm.
- Lateral Deltoids: Situated on the side of the shoulder, these play a vital role in arm abduction (lifting your arm away from your body), external rotation, and other overhead movements.
- Posterior Deltoids: Found at the back of the shoulder, these enable you to extend your arm backward, assist in external rotation, and help with various pulling movements.
Understanding the function of each of these three parts allows for targeted exercises to improve shoulder strength and mobility.
