What is the main role of the biceps muscle?

The primary function of the biceps muscle is to curl and lift the arm, which is why this choice is correct. The biceps brachii, commonly referred to as the biceps, is situated in the upper arm and consists of two heads that allow for flexion at the elbow joint. When the biceps contracts, it pulls the forearm upward, enabling movements such as lifting objects toward the body or performing various curling motions. This action is essential for many daily activities and exercises, emphasizing the importance of bicep training in strength and conditioning programs.

Other choices may describe functions or muscles that are not directly related to the biceps. For example, extending the arm primarily involves the triceps muscle rather than the biceps. Breathing assists are provided by muscles like the diaphragm and intercostals, which do not include the biceps. Stabilization of the shoulder is typically the role of muscles such as the rotator cuff rather than the biceps, focusing on different aspects of movement and stability.