The dead bug is the exercise to work your abs without stressing and flexing the lower back. It is especially great for people with lower back issues who need to strengthen their core.
For most people “strengthening the core” means crutches and sit ups. But this kind of training involves a lot of spinal flexion, and too much flexion is already a problem in this world of sitting 10 hours a day. Since too much flexion, especially under load, might lead to injuries in the spine and discs.
The dead bug looks funny at first, what does moving your arms and legs has to do with the abs? But this exercise is not about how you move your limbs, it’s about training your abs to do one of their most important stability tasks – resisting extension.
The key to this exercise is to keep your back flat on the floor the whole time. As you lower the arm and leg your lower back will raise from the floor, your abs need to work hard to prevent that.
This is a great spine stabilization exercise, since it’s not about creating movement, but about preventing movement in the spine. Preventing unwanted movement is one very important ability of the core muscles. This will reduce your risk for injury while exercising and in everyday life.
Keep your back pressed on the floor. This is the most important rule, you should not be able to fit your hand between the lower back and the floor. This exercise is not about how low you move your arm and leg, but about your abs keeping your back straight from extension. If can’t keep the back from arching, lower the arm and leg a little less to the point you can keep the back straight.
Don’t do this exercise fast. Don’t swing your limbs up and down. Instead, move them slowly and focus on keeping your abs and core tight.
If you’re doing this exercise to deal with an injury, don’t work through the pain. Pain is usually a signal something is wrong. The dead bug is a great rehabilitation exercise to help with a back or spine injury. But every injury is different, if you feel pain, stop doing this exercise and advice a physical therapist.