They work the lateral head & traps, but they also lead to biceps tendonitis, bursitis, impingement, and carpal tunnel when done to often or done wrong.
To have your palms prontated & shoulder internally rotated causes the head of the humerus to move forward and pinch the tendon of the long head of the biceps and places undue pressure on the sub-acromial bursae by pushing into the scapula.
The best way to perfrom it is with a medium grip,, scapula retracted, standing completely upright, NO swiging and pull the straight up and close to your body. Stop when elbow is parallel to the ground - do not pull higher.
S