Which muscle group is primarily targeted by bicep curls?

• A. Biceps
• B. Quadriceps
• C. Gluteus maximus
• D. Deltoids

Answer: (A)

The main concept here is identifying which muscle is doing most of the work during a curl movement. In a bicep curl, bending the elbow against resistance largely relies on the biceps brachii. This muscle runs from the shoulder to the radius and tightens as you curl the forearm toward the upper arm, especially when the palm faces up (supinated grip). That position maximizes biceps involvement.

The other options aren’t the primary movers for this action: the quadriceps run at the front of the thigh to extend the knee, not affect elbow motion; the gluteus maximus powers hip extension, not elbow flexion; and the deltoids are shoulder muscles involved in lifting and stabilizing the arm rather than bending the elbow. There are assistive muscles like the brachialis and brachioradialis that contribute, particularly with different grips, but the biceps is the main muscle targeted by a traditional curl.