Upper body strength exercises arm strength and pull-ups. In fact, playing basketball and rebounding more will naturally develop shoulder width. If you want to hook the ball with your fingers, your hand length and shoulder width will naturally increase. Just like giraffes eat leaves from high places, their necks will naturally grow, so they should grab more rebounds and attack continuously. Jump only with your calves and jump continuously. I just practice rebounding to widen my shoulders, my chest is not too thick, my upper limbs are developed, and my lower limbs are similar.