I’ve been thinking lately about falls. Not falls as in autumn or as in water (despite the photo). But falls as in tumbles, collapses, sudden drops from vertical to horizontal. A sign at the hospital yesterday: “Let’s be fall free on 3B.” Something I seldom think about at all, strolling down a corridor or stepping off a curb, is quite an achievement for others.

It is a gift, this upright posture, these legs that can stride and arms that can swing. The simplest motions of the day are the product of countless neural firings, of muscles expanding and contracting — a complicated calculus of movement and balance. Of defying gravity.