What is the large muscle that covers the front of the humerus?

The biceps brachii is the large muscle that covers the front of the humerus. It is located in the upper arm and is primarily responsible for flexing the elbow and supinating the forearm. The biceps consist of two heads, which originate from different points on the shoulder and insert onto the radius bone in the forearm. Its prominence on the anterior side of the humerus makes it a key muscle in movements such as lifting or pulling.

In contrast, the triceps muscle is located at the back of the arm and is responsible for extending the elbow. The deltoid muscle is situated over the shoulder and is primarily involved in shoulder abduction, flexion, and extension. The rotator cuff consists of a group of muscles and tendons that stabilize the shoulder joint rather than being a single muscle that covers the front of the humerus. Understanding these distinctions clarifies why the biceps is the appropriate answer to the question.