I've hit a slump in my pokerplaying, losing some heads-up and tournaments. Always the same reason; the blinds are high and partaking in a hand means committing your whole stack, and if it doesn't hold up, you're out.
And I pulled a back muscle in my sleep. Searing, stabbing, debilitating pain ensues when I have back and arm muscles in certain non-deterministic configurations. I'm talking Gaius Julius Caesar "Hi, Brutus! Greetings, senators! Nyy-AARRRGHH!" pain here.