There are two kinds of mountain bike crashes: those that take place at speed or involve large external objects; and those where the cyclist falls, usually at very low speed, and injures the part of the body used to stop the fall. My most recent crash was an example of the latter; my left thumb took the weight of my body as I tried to protect myself from the rocky trail.
My thumb was sore and swollen, and by morning, I couldn't flick open my toothpaste tube or press the disconnect button on my mobile phone, small tasks I realized, for the first time, I usually reserved for my nondominant thumb. Lynn was physician on duty at the after-hours service. She looked over the digit carefully, tested my strength, localized the pain, and looked up at me.