Apparently I am unbalanced or, at least, my grip is. On Friday the physiotherapists I share an office with brought up a couple of dynamometers and we all had a go. I can’t remember the exact readings but my right hand is reasonably strong and my left hand exceeds that by some margin. That’s got to be down to years of bass playing (and especially the workout that my electric upright bass gives me).
No testing yet for any other kind of imbalance though!