There are many ways an organist can end up with a stiff neck from tilting the head too far backward while playing.
This (photo) is one of them.
If they've worked with a choir long enough, all organists have done this (photo) or something like it -- occasions often arise when there simply isn't enough time to get a choir accompaniment into tight motor memory before it must be performed.
Attempting to sight read from a high rack is one thing, but when the pages of the score are piled even higher and the player's view is partially blocked by a music lamp, indeed, it can get worse ...
When a hand must leave the keys to turn a page during performance several obvious problems develop: a) unless a rest is written into the music to accommodate a hand leaving the keys, all of the notes fail to get played, b) attention to the score is diverted for a moment which requires the eyes to return to the exact spot and hopefully not lose one's place, c) if the turning isn't done with great haste and precision the rhythm can be disrupted, and d) worse still, part of the score can fall off the rack -- a calamity virtually guaranteed to lead to a breakdown.
An organist can be a very capable player and otherwise quite well prepared and still end up suffering through this kind of stress and embarassment in performance, even when page turning was made a part of regular practice.
Using cellophane tape to construct a billboard (photo) of pages can be one solution, albeit not the best in terms of balance.