HOW: Start by standing straight up with a dumbbell in each hand. With your elbows squeezing your side and your shoulder blades back, bend your elbows up towards you as you rotate your hands out. Lower the dumbbells back down into the starting position and repeat.
FEEL: You should feel your biceps muscle working.
COMPENSATION: Don’t lean back as you curl up, stay straight up. Keep your traps relaxed, don’t shrug as your curl.