I've got a pre-concussion background that includes soft-style martial arts, yoga, climbing, cycling, gymnastics, ballet, etc. My ability to perceive myself in space and navigate that space was top-notch. I could easily walk around the house, or walk a balance beam, with my eyes closed.

Post-concussion I've got some very big vestibular problems. Walking and standing are challenging. Getting back on a bicycle seems suicidal. More than once I've stumbled past small groups of hobos (drinking cheap booze from paper bags) and been greeted with "Hey man, are you alright? You need any help, man?" I'm not proud, but am I'm not ashamed to admit it.

Certain sounds make me dizzy. Loud noises make me jump.

I had a few sessions with a neuro-vestibular-physiotherapist, and she told me that if it wasn't for my background with physical movement, I probably wouldn't have been able to stand up: that's how bad my balance was (still is?). At the last session she mentioned that it made no sense to her that in some ways I was improving, but in other ways I wasn't. If anyone can comment on that...

Anyway, one of the things I've learned to do pre-concussion is allow myself to use visual and tactile feedback to control my balance. Post-concussion, it's the only way I can stand up. 9+ months later and still, if something moves through my field of vision it will almost knock me over.

I can stand in a doctors office, visually focus on a point, and walk in a dead-straight line for a a meter or two. But if you put me on a sidewalk with noise, cars, buses, people, etc then I stumble like a drunk. In laboratory conditions my balance is fine, according to that test. Everyone is different, but even for people without a background in physical movement the "laboratory conditions" of a doctors office, combined with a very brief test, could probably make things look better than they really are.