Bird dog on a wobbly dome turns a steady drill into a stability test.
Keep your hips square to the floor, do not let them tip toward the lifted leg.
The bird dog is anti-rotation core training, extending one arm and the opposite leg dares your trunk to twist, and your job is to refuse, and putting your hands and knees on a dome removes the stable floor that normally makes refusing easy. Every reach becomes a live negotiation between the extending limbs and the deep core muscles keeping your hips square and back flat. It earns its place as spine-friendly core work that scales in difficulty with nothing added but wobble.
The floor version gets easy fast, and the dome restores the challenge by making your base unstable. The same slow reach now demands far more from the deep core muscles that keep your hips and spine still.
Tipping the hips toward the lifted leg, which turns core work into a lower back arch. Imagine balancing a cup of water on your lower back, if it would spill sideways, shorten the reach until it would not.
Slow enough that nothing wobbles, roughly 2 to 3 seconds out, a brief hold level, and 2 to 3 seconds back. On the dome, speed is the enemy, every fast rep is a balance save rather than core training.
