Nine chances out of ten, it's wrong means that 90% of the time, the place the person is, or wants to go is a wrong judgment that only has 10% chance of being a good option. This means that the probability of been wrong is 9/10 which is very high.
Mr Buckingham is trying to tell them to be somewhere else that 90% more probable of being a good option so as to maximize their decision making.
This is referred to as DOMS, Delayed Onset Muscle Sorenes. The exact mechanism is not understood, but DOMS appears to occur due to connective tissue microtrauma.
