Avoid excessive movement in your torso and ‘dropping’ the dumbbells too quicklyd.
Stand tall holding a pair of dumbbells at your waist, in front of your body. (A) Keeping your core tight pull the dumbbells up towards your chin, driving your elbows up and back (B). Slowly lower back down to your waist under complete control. Avoid excessive movement in your torso and ‘dropping’ the dumbbells too quicklyd.