Let's bust the myth first: poo stance is not a flexibility problem, and it's not something you're stuck with. It's a substitution — your body swapping one movement for another under pressure — and substitutions can be un-swapped.
You know the shape. Knees splayed wide, hips dropped straight down, back rounded, arms out like you're carrying invisible shopping bags. It photographs about as well as it sounds. But nobody chooses it. It appears on its own the moment the wave gets real.
What your body is actually doing
Here's the mechanics. When you feel unstable, your nervous system wants to get low, fast. The quickest way down is a squat: knees out, hips sink, back curls. It works — you are lower — but it's the shape of a person absorbing a fall, not a person driving a board. Splayed knees can't shift weight along the board's length, and a hunched back locks your hips out of the steering.
What surfing wants instead is a hinge with bent knees. About 45 degrees of knee flex — a bend, not a squat — with the knees tracking slightly in over your feet, hips folded slightly forward, chest up over the board. Same height reduction, completely different machine. From this shape you can push, absorb, and steer, because your knees and hips are stacked to move along the board rather than just downward.
So the sequence to remember is: instability triggers the squat, the squat creates the poo stance, and the poo stance then makes you less stable, which deepens the squat. Break the loop at the trigger — build stability in the hinged shape — and the poo stance quietly leaves.
What the camera sees
The measurable version of this is knee flex in your riding stance. Around 45 degrees of bend is the target zone; a much deeper angle with the hips sunk usually means you've dropped into the squat. CoachVision estimates that knee angle from a beach clip, so you can check whether "I felt low" was a bend or a crouch — the two feel identical from the inside and look nothing alike from the outside.
Train the shape until it's the default
The drill is Balance-Board Stance Holds: five holds of 45 seconds.
Get on a balance board (a cushion or wobble pad works while you're getting one). Set your surf stance — feet shoulder-width or a touch wider, back foot where the fins would be. Now build the shape from the ground up: knees bent about 45 degrees and tracking slightly in, hips shifted a touch toward the front foot, chest tall, eyes on a point at horizon height. Not your feet. The horizon.
Hold 45 seconds. Rest. Five rounds. The wobble is the entire point — every correction you make while holding the hinged shape is one rep of "stay stable without squatting." When 45 seconds gets comfortable, add slow squats on the board without letting the knees splay or the chest drop.
Two weeks of daily holds and the hinge starts showing up in the water uninvited, which is exactly how you want it to arrive. The poo stance was never a verdict on your surfing — it was just your body's first draft of getting low. You're about to hand it a better one.