Which of the following is not an axial muscle?

• A. None of these
• B. Leg muscles
• C. Neck muscle
• D. Biceps

Answer: (B)

Axial muscles are the muscles located along the body's central axis—the head, neck, and trunk—primarily supporting posture and moving the spine and rib cage. Muscles of the limbs belong to the appendicular group and move the arms and legs. So a leg muscle is not part of the axial group. The neck muscles sit on the body's axis, so they are axial. The biceps, while not part of the trunk, are muscles of the upper limb and are also considered appendicular. Therefore, leg muscles serve as a clear example of not being axial, since they belong to the limb-related (appendicular) muscles rather than the central axis.