beginneranti-rotationopen-chainunilateralSource-checked

Bird-Dog

Also called: Quadruped opposite arm/leg reach

Primary muscles: Multifidus

Secondary muscles: Erector spinae, Quadratus lumborum

Joints / actions: Lumbar intervertebral joints (isometric stabilization (neutral held))

Plane: multiple

Equipment: bodyweight

What it is

On hands and knees, extending one arm and the opposite leg while keeping the spine still and level.

Purpose

Trains spinal stability and control — resisting unwanted motion rather than producing it — a foundation for safe lifting.

Starting position

Start on hands and knees (quadruped), hands under shoulders, knees under hips, spine in a neutral (flat) position.

Step by step

Brace the core gently and extend one arm straight forward while extending the opposite leg straight back.
Keep the hips and shoulders level and the low back still — do not let it sag or rotate.
Hold briefly, return with control, and repeat on the other side.

Breathing

Breathe steadily throughout; do not hold your breath.

Coaching cues

"Imagine a cup of water balanced on your low back — don't spill it."

Common mistakes

Letting the low back sag or arch; rotating the hips or shoulders; rushing the movement.

Easier regression

Move only the arm, or only the leg, rather than both together; reduce range of motion.

Harder progression

Add a light hold at end range, or add resistance (light ankle/wrist weights) once control is excellent.

Alternatives

Dead bug (core region), plank.

Who may benefit

Nearly everyone, especially beginners and anyone building a foundation of spinal control before loaded lifting.

Who should modify or avoid it

Generally very safe; those with acute pain that worsens with this movement should seek individual guidance.

Why this exercise works

By challenging the trunk to resist rotation and sagging while a limb moves, it trains the deep stabilizers (multifidus, quadratus lumborum, deep core) to hold a neutral spine under a changing load — exactly the skill needed to protect the back during real lifts.

⚠ Safety note

This is a low-load control exercise appropriate for most people, including those returning to exercise after minor back discomfort; if it reproduces pain, reduce range (e.g., arm or leg only) or stop and seek guidance.

Sources

“Exercises that build core and back strength and control can be part of managing and preventing low back pain.”

National Institute of Arthritis and Musculoskeletal and Skin Diseases — NIH / NIAMS · Back Pain

Government / official guideline · License: Public domain (U.S. government work) unless otherwise noted. · Last checked 2026-07-19

“The multifidus provides segmental stabilization of the vertebral column.”

Anatomy and Physiology 2e — OpenStax, Rice University · Ch. 11.4 Axial Muscles of the Abdominal Wall, and Thorax and the Deep Back

Peer-reviewed textbook · License: CC BY-NC-SA 4.0 · Last checked 2026-07-19