Dead Bug

Lie supine with arms reaching toward the ceiling and hips and knees bent to 90° ("tabletop" legs). Brace the core (Abdominal Bracing (vs Hollowing)) and flatten the lower back gently into the floor (no daylight under the lumbar spine; see Spine Positioning — "S" Shape, Never "C"). Slowly lower one arm overhead toward the floor and the opposite leg toward the floor (straightening the knee), keeping the low back pressed flat. Return under control and alternate.

The challenge is anti-extension: as the contralateral limbs reach away, they pull the pelvis toward an anterior tilt and the lumbar spine toward arching; the deep core (Transverse Abdominis) and Rectus Abdominis must resist this and keep the spine still (see Anti-Movement Core Training (Anti-Extension, Anti-Rotation, Anti-Lateral-Flexion)). It is the supine counterpart to the bird-dog (Bird-Dog) and is often easier to learn because the floor gives feedback.

Coaching:

• The lower back must stay flat throughout — the moment it arches, you have gone too far; shorten the limb reach.
• Exhale as the limbs extend; move slowly and deliberately.
• Keep the head/neck relaxed on the floor.

Progressions (see Balance Training Progression): increase limb reach/lower toward the floor → slow the tempo / add brief holds → hold a light weight or band → reduce to fully straight limbs. Regression: move only one limb at a time, or keep the moving leg's knee bent.

• Supine, tabletop legs, arms up; lower opposite arm + leg while keeping the low back flat.
• Trains anti-extension core stability (deep core + rectus abdominis).
• Low back staying flat is the standard — arching means too much range.
• Supine counterpart to bird-dog; easier to learn (floor feedback).
• Progress: more reach → slower/holds → light load; regress to single-limb / bent knee.