Originally Posted by
Loose rivets
Detritus coming off a glider's floor or cows getting bigger to the point our shoulder harnesses are tugging, is serious stuff. I find it hard to imagine being near the surface, especially flat out, and even letting the controls go forward a micro-tad. I think it would be one heck of a mental battle to Yo-yo, even if you knew it was the procedure.
On a hanglider, the standard procedure for going into negative G (and therefore loosing all weight-shift control) is to pull the bar in, to get the C of G as far forwards as possible and reduce the chances of the glider tumbling 180 degrees or more. However, I did once see someone's high speed dive from a complete low altitude stall, get somewhat slowed by the glider tumbling and structurally failing, inverted, just before impact. That probably saved his life.