A squat is a squat, so we teach all the squats, from air to back to front to OHS with the same stance. Additionally the mechanics of the squat are the same. The hips drive back and down, the knees bend to support the movement. If you watch someone who has trained with us for a long time and vid them squatting from the hips down, you will not see much difference throughout the range of movements. The novice mistake with the OHS is to start the movement at the knees to keep the torso upright.
Grip width is optimally set so that the bar is 8 - 12 inches above the head. However, shoulder flexibility and safety are a primary concern. A good way to determine hand spacing is to do a few dislocates. When it starts getting difficult to pass the bar through back off a little. That is generally a good place to hold the bar in OHS and snatch. It allows for an unrestricted pass through if you lose the bar back.
The bar needs to be centered over you mid foot throughout the movement. If you are inflexible in the hips your body will tend to pitch forward as you squat, to the degree of inflexibility. I have seen people OHS are so inflexible that their body in horizontal to the ground in the bottom position. Although not optimal the squat is still good if their hips are below parallel. In this case if their shoulders are flexible they will roll their shoulders back as their body inclinates forward. The bar remains above their mid foot throughout. If they were to keep the bar above over their head it would be well away from their center of gravity.
