Step 6: Shoulder and Upper Arm Muscles

The Spinodeltoid is the large shoulder muscle. The Deltoid is superficial to this muscle and is easily destroyed because it lies within the connective tissue. Due to the fact that the Deltoid is underdeveloped it is hard to identify.

The Acromiodeltoid is superior to the Spinodeltoid and looks like a flap of muscle.

The Brachiocephalic is the muscle that originates from the back of the neck and inserts in the humerus. It is vertical and somewhat thick.

 The Triceps Brachii splits into two parts: Triceps Brachii Long Head and Triceps Brachii Lateral Head. The Lateral head is closer to the Brachiocephalic while the Long head runs towards the back. Both of these muscles help extend the elbow. The picture below shows the two muscles before they are separated.

Break between Long head and Lateral head

Here are the muscles after separation

The Biceps Brachii is located in the same area as a human's biceps. It is thick and originates from the scapula.

Bicep Brachii is between blunt probe and tweezers