Bodyweight-Strength-Training-Anatomy

Figure 2.1 Biceps brachii, brachialis, and brachioradialis.
The back of the upper arm is composed of the elbow extensors.
Elbow extension is moving the wrist away from the shoulder by
straightening the arm to form a solid line from shoulder to wrist.
The primary elbow extensors consist of the three individual heads
of the triceps brachii-the long head, medial head, and lateral
head (figure 2.2).