Similar to the Bird-dog exercise, the Deadbug exercise is a great early core strengthening exercise. While many people are familiar with crunches or sit-ups and possibly even the more difficult double leg lift,
Double leg lift: Extremely hard to do right!
most people fail to notice how much their low back may be bending and twisting with these exercises. The Deadbug provides a safer way of anterior trunk (the stomach muscles) strengthening with an extra focus on spinal (low back) stability.
Instructions:
Begin by laying your back in the hook lying position
Find neutral spine. You should have a small curve in your low back where your hand should barely fit underneath your spine (see previous posts to help find neutral spine)
Lift one leg up at a time to the 90-90 position (hips flexed 90 degrees, knees flexed 90 degrees) so that your thighs are vertical, and your shins are horizontal
Make sure that as you do this your pelvis (and your low back) doesn’t move in any direction. You may have to feel your abdominals contract to help stabilize
Once you’ve lifted the legs, put the arms straight up in the air. You’ve now reached the starting position!
Slowly lower one leg back to the ground and the opposite arm to the floor behind your head. Then bring them back up and repeat on the other side all without moving your back and pelvis. This is 1 rep. Try to do 10 on each side which should take you about 90 seconds total.
Common mistakes:
Letting your low back move
Tips: If you find it too difficult, you can use some simple tools to make it easier.
To help maintain neutral spine, roll up a small towel/t-shirt and place it in the space underneath your low back. With something for your back to press on, it’ll be easier to keep the same position while doing the exercise.
Advanced:
To increase the difficulty, try straightening out your legs. You can even add light ankle weights. Just make sure that no matter how hard you make it, you keep the same form in your back.
For increased rotational challenge, have your legs go out to the side. Here you must make sure to not let your pelvis rock to one side.
Learn To Move 