Kawa rough landing?

There is a comment from GP gliders on their facebook page that Mr Kawa hurt his back as a result of the impact (hopefully not seriously) and also that the dynafoam cushion had been removed so that he could fit into the smaller sized cockpit of the two GP glider designs. Irrespective of whether the dynafoam would have made a difference in this particular incident it is a reminder of the importance of impact protection seat cushions and raises a question about flying a glider with a cockpit so small that the cushion needs to be removed for the pilot to fit into it.