The Numbers Are In . . .

[Emperor Ump]

In the scissors stance your chest is generally at a sharper angle to the ground than the box. This sharper angle causes your head to be up (distance from chin to chest) as opposed to the box. This angle of your neck gives your neck less of its natural 'shock absorbing' ability. Not only that but to be at this angle your neck is using more muscle thus increasing its resistance to other forces.

Here's an example you can do at home to demonstrate:

1) Sit at your computer desk straight up (or with your elbows on your desk to simulate the angle of your chest when working the box) looking at some point on the wall
2) While sitting straight/elbows on knees up look up at the ceiling.
3) Notice how far your head moved and how easy it was.
4) Now sit at your desk crouched forward, say with your elbows on your knees. This may be a similar angle of your chest if you were working the scissors.
5) With your elbows on your knees look up

Notice the difference in your head mobility. You weren't able to look directly up, were you? And it wasn't as easy.

This is the same principle as when you're hit in the mask with a ball. Sitting up or from the box your neck has more ability and movement to absorb the impact, than crouched over or in the scissors.

This extra resistance can cause more injury.