A virus destroyed Ian Waterman’s kinesthetic and other mechano-cutaneous nerves when he was 19 years old. Lacking proprioception, the sense of knowing the relative position of various part of the body, Ian was bound to a wheelchair for a long time. Now, he relies on vision to know where his limbs are. If there is no light, he cannot tie his shoes, walk up or down stairs, or clap his hands. At one point in his life, he was stuck in an elevator, with the lights off. He was unable to remain standing and could only stand when the lights turned back on. Proprioception is one of many senses we take for granted, being able to know where your limbs are, even while closing your eyes. Here’s a less than scientific, but informative, video about Ian Waterman.
You can read more in Jonathon Cole’s book, Pride and a Daily Marathon.