The dead bug is a core exercise done lying on your back: arms point at the ceiling, hips and knees bent to 90 degrees, and you slowly lower one arm and the opposite leg while the lower back stays steady. It trains the trunk to resist arching while the limbs move, which is why physical therapists use it for low back pain and spondylolisthesis. Treat this page as general education; whether it fits you, and how many to do, is for a therapist to decide after an exam.
Last updated By the Monon Therapy Collective editorial team
- What it trains
- Resisting low back arching while the limbs move
- Start position
- On your back, arms up, hips and knees at 90 degrees
- Key cue
- Breathe out and keep the ribs heavy
- Often used for
- Low back pain, spondylolisthesis
What is the dead bug training, if not your abs?
The dead bug trains the deep abdominal and oblique muscles to hold the pelvis and ribs still while your arms and legs move away from the body. Physical therapists call that anti-extension control: the job is to stop the lower back from arching, not to curl the trunk up as a crunch does.
That matters because most daily tasks look like a slow dead bug. Reaching for a high shelf, carrying a laundry basket or swinging a leg out of the car all ask the trunk to stay steady while a limb moves. Lying down lets you learn the pattern before trying it standing.
Why is the dead bug common in low back pain and spondylolisthesis rehab?
It is common because it trains trunk control with almost no compression on the spine and without bending the back backward, which many sore backs dislike. For low back pain, it is often one of the first core exercises a therapist teaches because it can be scaled down to tiny heel taps.
With spondylolisthesis, where one vertebra has slipped forward on the one below, arching the low back often provokes symptoms. Learning to hold the back steady while the legs lower gives that person a way to train without the position that hurts. The same reasoning applies to young athletes recovering from a stress fracture in the low back, covered on the teen athletes page.
What should my lower back do during a dead bug?
It should stay where it started, neither flattening hard into the mat nor lifting off it as the limbs lower. Therapists differ on whether the back should begin in light contact or with a small natural curve; what they agree on is that it should not change during the repetition.
A simple check is to slide one hand under the small of your back before you start. If the pressure on your hand fades as a leg lowers, the back is arching, and the leg went too far. Shorten the range until the pressure stays even. A therapist can watch this for you; the low back questionnaire starts the match.
Dead bug mistakes that make the exercise pointless
Most dead bug mistakes come from chasing range instead of control. A small, steady movement is worth more than a full reach with the back arching.
- Lowering the leg so far that the back lifts off the mat.
- Holding the breath, which stiffens the trunk without teaching control.
- Letting the ribs flare up as the arm goes overhead.
- Moving fast, so momentum carries the limbs.
Easier and harder dead bug versions
Easier versions move one limb at a time or shorten the lever; harder versions straighten the leg or add resistance.
- Easiest: feet on the floor, knees bent, slide one heel out and back while the arms rest.
- Easier: legs in tabletop, tap one heel to the floor while the arms stay up.
- Standard: opposite arm and leg lower together.
- Harder: lower a straight leg instead of a bent one.
- Harder still: hold a light weight in each hand or add a band anchored behind your head.
Dead bug, step by step
Go slowly enough that you could stop at any point in the movement without the back shifting.
Lie down and stack the limbs
Lie on your back on a mat. Lift your legs into a tabletop position, hips and knees bent to about 90 degrees, and reach both arms straight up over your shoulders.
Set the ribs with a breath
Breathe out slowly through pursed lips and let the lower ribs settle toward your hips. The lower back rests lightly on the mat; it should not be pressed hard into it or lifting off it.
Lower the opposite arm and leg
Take about three seconds to reach the right arm back over your head and lower the left heel toward the floor. Stop the moment you feel the lower back begin to lift.
Return and switch sides
Bring the arm and leg back to the start, take a breath, then lower the left arm and right leg the same way.
End before the form fades
Finish the set when the back starts to arch or you start holding your breath. A therapist sets how many repetitions and sets suit you.
Stop the dead bug and get checked if...
- Pain, tingling or numbness travels below the knee.
- You notice numbness in the groin or inner thighs, or new bladder or bowel changes: that needs emergency care.
- You have a fever, have lost weight without trying, or have had cancer, and the back pain is new.
- Pain at night is not eased by changing position.
- A sharp pain during the exercise is still there hours later.
If you think it is an emergency, call 911.
