Vomiting itself involves forceful contractions of the abdominal muscles, leading to expulsion of fluid, froth or food. (lienanimal.com)
Let me share with you a way to make this powerful exercise even MORE effective using a breakthrough «thumb trick» to get more forceful contractions and better pec development Thumb Rotation Chest Training Tip (try during your next workout): 1. (truthaboutabs.com)
It might rather be that it is the anterior and medial position of the insertion on the pubic bone that increases the stress in the high risk movements with forceful contractions including both hip abduction and hip extension [checkout hip rotation in breaststroke]. (thoughtco.com)