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Balance
Balance

Dead Bug

Evidence-grounded — sourced from Fysiqal's fitness knowledge graph· 2 min read
core-stabilityanti-extensiondead-bugsupinelumbar-stabilityneuromotor

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In one line

Lie on your back and lower an opposite arm and leg while pinning the low back to the floor — a beginner-friendly anti-extension core-stability drill and the supine partner to the bird-dog.

Detail

Lie supine with arms reaching toward the ceiling and hips and knees bent to 90° ("tabletop" legs). Brace the core (bracing) and flatten the lower back gently into the floor (no daylight under the lumbar spine; see spine-positioning). 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-concepts). It is the supine counterpart to the bird-dog (exercise-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.

Key facts

  • 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.

Connections

  • core-stability-vs-strength — a key stability drill.
  • anti-movement-concepts — anti-extension category.
  • bracing — keeps the spine neutral/flat.
  • exercise-bird-dog — quadruped counterpart.
  • transverse-abdominis, rectus-abdominis — primary stabilizers.
SourceCurrent guideline bodies
Authored from established core-stability consensus.
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Educational content only — not medical advice. Always consult a qualified professional for individualized guidance, especially around injury, pregnancy, or medical conditions.

Explore related topics

Atlas Connections

Rectus Abdominis
The "abs"; a long strap-like trunk flexor split into left/right halves by the linea alba.
Transverse Abdominis
The deepest abdominal muscle; compresses the abdomen, supports the abdominal contents, and aids lower-back stability.
Anti-Movement Core Training (Anti-Extension, Anti-Rotation, Anti-Lateral-Flexion)Closely related
Train the core by *resisting* motion the limbs or a load try to impose — anti-extension, anti-rotation, and anti-lateral-flexion — rather than by repeatedly flexing the spine.
Balance Training Progression
Make balance harder by shrinking or destabilizing the base of support and removing sensory inputs — a staircase from two-feet stable to single-leg, eyes-closed, unstable-surface, and perturbation work.
Abdominal Bracing (vs Hollowing)Closely related
Stiffening the whole trunk wall — like bracing for a punch — to lock the spine in neutral and create a rigid base for the limbs to work from; the foundational core-stability skill.
Core Stability vs Core StrengthClosely related
Core strength is how much force the trunk muscles can produce; core stability is the trunk's ability to *resist unwanted motion* and keep the spine controlled — and for back health and force transfer, stability usually matters more.
Bird-DogClosely related
From hands-and-knees, extend the opposite arm and leg while keeping the spine perfectly still — a contralateral coordination and anti-rotation core-stability staple.
Spine Positioning — "S" Shape, Never "C"
Stabilize the spine by holding it in a semi-isometric contraction so it keeps its natural "S" shape — never allow a "C"-shaped spine during exercise.