Exercise of the Week - Ball: One legged Leg press
Begin in an incline position on the ball, knees bent.   Straighten the left leg out in front of you and push through the heel of the  right foot to push up on the ball.   Lower and repeat for 1-2 sets of 10-16 reps on each side. 
Make it easier:  Hold onto a wall or place fingertips on the floor for balance
 Glute, Hip and Thigh Exercises