Dead bug
Lying on your back moving opposite limbs while your back stays flat — trunk control with the load taken off entirely.
- Pattern
- Anti-extension
- Equipment
- Nothing needed
- Space
- Floor space
- Difficulty
- Foundational
- Load
- Leverage
- Side
- One side at a time
What it is
Lie on your back. Bring your knees up over your hips, bent to a right angle, and reach your arms straight up towards the ceiling.
Press your lower back gently into the floor so there is no gap under it. Then slowly lower one arm back over your head and the opposite leg down towards the floor, keeping your back flat. Return, and repeat on the other side.
The badly-named part is the picture it makes: an upturned insect.
What it demands
Keeping the lower back still while the limbs move. That is the entire content. As the arm and leg extend, the pull on the pelvis increases and the lower back wants to arch off the floor. Preventing that is rectus abdominis and the deeper abdominal wall working while nothing visible happens.
Coordination, in the ordinary sense of moving opposite limbs together. Some people find this genuinely awkward at first, which is information rather than a problem.
Almost no strength, and no ability to hold your own weight. It can be done by people for whom a plank is out of reach.
What usually goes wrong
The lower back lifts. The gap appears under it and the exercise stops working. The fix is to lower the limbs less far, not to try harder.
Moving too fast. Speed hides the failure. Slower is harder here, which is unusual and useful.
Holding the breath. Breathing normally while the trunk stays braced is part of the skill and the reason the movement transfers.
Same-side limbs. Opposite arm and leg, not the pair on one side.
Where it sits
The most accessible trunk movement in the collection: no load, no balance, nothing to hold up, and a clear signal when it has failed.
It trains the same thing a plank does — resisting extension of the lower back — but with the limbs moving, which is closer to what the trunk does in life. The bird dog is the same idea on hands and knees, adding a resisting-rotation demand the dead bug does not have.