Shoulders and arms work together but they require significantly different exercises to make them bigger and stronger. The main muscles found in these areas are as follows:
1. Deltoid :
this is comprised of three separate segments that cover the shoulder and run a few inches down the arm. The anterior deltoid raises the arm to the front. The middle deltoid raises the arm to the side. The posterior deltoid draws the arm backwards.
2. Rotators :
these are small muscles of the rotator cuff that control small movements of the upper arm. Consisting of an internal rotator, external rotator and supraspinatus they are used in lifting and throwing actions.
3. Biceps brachii :
the biceps covers the front part of the upper arm and consists of a long head and a short head. The long head crosses the shoulder joint and works with the front deltoid to raise the arm to the front.
4. Triceps brachii :
the triceps covers the the back of the upper arm and consists of three sections – the long, lateral and medial heads. The role of the triceps is to straighten the arm at the elbow.
5. Brachialis :
this muscle lies between the upper arm bone and biceps. It helps the biceps to bend the elbow when the palm is facing sideways.
6. Forearm muscles
the forearms consist of many little muscles called flexors and extensors. The largest forearm muscle is the brachioradialis that lies close to the elbow.
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