bicep curls

The bicep curl mainly targets the biceps brachii, brachialis and brachioradialis muscles. The biceps is stronger at elbow flexion when the forearm is supinated (palms turned upward) and weaker when the forearm is pronated.[1] The brachioradialis is at its most effective when the palms are facing inward, and the brachialis is unaffected by forearm rotation. Therefore, the degree of forearm rotation affects the degree of muscle recruitment between the three muscles. A bicep curl usually starts with the arm in a fully extended position, holding a weight with a supinated (palms facing up) grip. A full repetition consists of bending or curling the elbow until it is fully flexed, then slowly lowering the weight to the starting position. The torso should remain upright instead of swinging back and forth, as doing so transfers the load away from the biceps and onto other muscles, reducing the effectiveness of the exercise. The elbows are also usually kept stationary at the side of the torso, as allowing the elbows to move in front of the weight's center of gravity removes tension on the biceps before full contraction is achieved.[2]