Frank,
The shock absorber used by Otto was a willow hoop attached to the front of the glider. This would have helped in the event of it going in nose first. The aerofoil of his gliders had a sharp leading edge and the stall characteristic is very abrupt and can easily catch you out. The pilot weight needs to be kept forward and there are pads behind the shoulders to keep the pilot in the correct position. Unfortunately Stephan (Nitsch) left the pads off of his portable Lilienthal replica and I found out about the stall, the hard way,when I tried flying it. https://www.youtube.com/watch?v=mpDrGLF51SY
The hoop was not fitted so I am not sure how effective it would have been?
Tony