The exercise ball crunch is a great all round ab exercise. Lower back support makes it ideal for those with lower back problems/injuries. Sit on the exercise ball with your feet flat on the floor wider than shoulder with apart.

Step forward with your feet allowing the exercise ball to roll back to your lower back.

Touch the side of your head with the tips of your fingers. This is the start position.

Crunching your abs, pull your torso up so your elbows are aiming for your knees.

Squeeze the abs tight and pause.

Then lower back to the start position.

Repeat for desired reps.

Exercise Tips:

The longer you hold the crunch the harder your ab muscles have to work.

Increase the effectiveness of this exercise by holding the crunch for a slow count of 2.