Russian Twists
-Position yourself on the ball and  twist to your left then to your right using your shoulders as a base of support (BoS).
Apparatus used: 
  -Dumbbell          ___
  -Medicine ball    ___ (shown)
  -Nothing             ___
  Competency Criteria
Client is able to twist without any pain in their knees or lower back.
Client maintains a relatively stable lower body and moves primarily with torso and arms.
Client maintains head contact on the ball unless he/she fully rotates sideways on ball.