Contortion Wiki

A balance where weight is supported primarily above the clavicles, but not the scull. This is usually not the only support; hands or knees usually provide supplementary support.

If the performer is “putting weight on their neck”, it's shoulderstand, intentional or not. This can lead to significant difficulty breathing (which you should confirm you're doing regularly - do not hold your breath), on top of reduced lung capacity due to the twisting of the pose.