Downhill Ski Style Exercise on Ball with Dumbbell - (intermediate)
(Thighs, shoulders, back, hips)

                                                                   
                                                     

1- Sit on the ball, back straight, feet firmly on the floor, about 16 inches apart.
2- Hold dumbbells at sides, at arms' length, palms in.
3- Start balancing dumbbells backward and forward to give a little push up.
4- As the arms move up, lift the buttock, don't put any weight on the ball but always keep contact with the ball.
5- When the arms are parallel to the floor, keep position for a few seconds.
6- Always keep back straight and head up.
7- Return to starting position.

Alternate exercise: - As you lift one arm up, with feet a little closer, stand on one foot (opposite foot). example: - Balance both arms backward, as you lift forward, right arm up only, transfer weight on your left foot, stand on left foot. Keep position for a few seconds. Keep contact with the ball. Return to starting position. Alternate. 
(more advanced exercise)

By Sylvain Lemaire - All rights to Physigraphe