Dead Bug

The Dead Bug is an exercise designed to strenghten the core muscles

Movements

Shoulder:
extension/Flexion
Hips
Flexion/extension
Knee
Flexion/extension

Muscles

The Dead Bug is a great exercise to activate the core, especially if you are having trouble with the plank. There are a fair few varieties you can do with this exercise. You can start easy by simply lowering a single leg with the knees bend at 90 degrees and move up to a more advanced movement using both arms and legs in extended position.

How to do it

For the easy version

Lie flat on your back with your arms held out in front of you pointing to the ceiling. Then bring your legs up so your knees are bent at 90-degree angles. This is your starting position, and it’s vital to get your back as flat against the floor as possible.
Slowly lower one heel towards the floor, keeping your knee bend at 90 degrees.
Making sure you press you keep your abs engaged the entire time.
Return this leg to its original position and repeat the same movement with the other leg

For a more advanced version.

While lowering your leg down, move your opposite arm towards the floor

For an even more advanced version,

Extend the leg when you lower it towards the floor (while still using the opposite arm as well)

Exercise Tips:

Your back must remain pressed into the mat at all times, your belly button should be pulled in
retract your shoulder and press the into the mat as well
If your back start to hurt, try bending your knee more during the exercise