Performing this abdominal exercise correctly is important so you don't strain your neck or compress your spine. In the beginning, break it down into two separate actions so you can focus on form and technique.

1 Lie on your back with both knees bent directly over your hips, keeping your shins parallel to the ceiling. Place your hands behind your head, allowing the weight of your head to be supported by your hands. Contract your abdominal muscles and raise your head.

2 On an exhale, raise your left shoulder higher off the floor while reaching your left arm to the outside of your right thigh. Straighten your left leg out in front of you. Pause as you focus on squeezing the right side of your midsection. Release, come back to center and return your left hand to the position behind your head. Repeat on the other side by twisting to your left and straightening your right leg and arm. Continue alternating sides until you have completed 16 reps on each side.

This article originally appeared in the Los Angeles Times in the "Good Form" feature of the Health Section. "Good Form" is updated with a new Karen Voight article each Monday.