i'm from austria, so i don't speak too good english but i think you should understand it ;)
so i'm jumping on a rail or box with a simple 90° to my left side . alright but as soon as i'm on the rail, my left foot (the rear one) slips to my right foot that now my center of gravity is behind my feet and i fall on my hip.
and if you fall successively, that quite hurts ..
so pls what can i do to not loose my balance !?