Open shoulders mean the arms are in line with the torso: ears past the arms, one straight column from hand to hip. Closed shoulders leave an angle there, and everything above it has to bend to make up for it.
What it looks like
From the side the arms and the torso do not make one line — the head sits in front of or behind the arms, and the shoulders look shrugged toward the ears. It usually arrives wearing an arch or a pike, because the bend is where the missing degrees went.
Why it happens
Overhead range, mostly: the shoulders cannot reach the position, so the spine or the hips donate the difference. Partly it is not pushing — the position lives at the top of a shrug, and passive arms never get there.
What it costs you
This is the fault behind most bent lines. Fix the shape without opening the shoulders and it comes straight back, because the body still has to find those degrees somewhere.
How to fix it
Push tall through the floor and let your ears come past your arms. Handstand shrugs at the wall build the push; shoulder-opener holds build the range. Both between sets, not instead of them.
Drills that fix it
Chest-to-wall hold
5 × 30–60s. Film one set from the side.
Belly and toes to the wall, hands 10–15cm out, ribs down, push tall through the shoulders. Only your toes touch.
Handstand shrugs
3 × 10 slow shrugs.
In a chest-to-wall handstand, shrug your shoulders up toward your ears and back down, slowly, without breaking the line.
Shoulder opener at the wall
3 × 45s, daily.
Kneel facing a wall, forearms on it above your head, sink your chest through. Ribs stay down — the stretch is in the shoulders, not the low back.
How Nstand measures it
Nstand measures the angle between the line of your arms and the line of your torso. More than 10° short of straight, averaged over the hold, is called shoulders not open.
It is a camera and some geometry. It does not replace a coach, a gym or an academy, it cannot see your wrists, your history or what you are about to land on, and it is wrong sometimes. Handstands can injure you. What you do on your hands is your decision and your risk: warm up, train where a fall is safe, and stop when something hurts.