Sit upright on a box or chair in a supported position. Squeeze your abdomen and drive your feet into the ground. With the dumbbells on your shoulders, the back side of the dumbbell sitting on your shoulder and your elbows facing forward.
Press the dumbbells up while working hard to maintain a neutral spine, keep your abdomen engaged and the lower part of your ribcage down. Once your elbows have locked out and the weight is overhead lower the weight down by leading with your elbows forward. You should finish the movement in the exact same position you started in.