The cross-body dumbbell hammer curl targets the biceps with an emphasis on the forearms. This exercise creates balance between the upper and lower regions of the arms.
Just like a standard hammer curl but because of the shift into your coronal plane (left and right), rather than in the sagittal plane (up and down movements), it engages your core strength, joint stability whilst improving wrist strength.
The cross body hammer curl really hits the brachialis hard, this is a small muscle between the tricep and bicep. As this muscle develops it will push your tricep and bicep further apart giving the appearance of a bigger arm!