Begin lying with your shoulders on the round side of a BOSU and feet on the ground with a 45 degree bend in your knees. Lift hips off the ground until you have a straight line from your shoulders to your knees. Hold a single dumbbell out over your head with elbows soft.
Contract abs throughout the movement and keep core solid. Using the back muscles, lift the dumbbell up and overhead in an arching motion until the db is straight overhead.
Slowly bring weight back out to the starting position, with the dumbbell extended parrallel with the ground.
Julie's Tip: This movement has to be slow and concentrated through your back to make it work!