If you are applying for the same kind of job in which you were injured, you will need to demonstrate that you know how the accident happened and what you can do to keep such things from happening again. If you are applying for a different kind of job, simply tell the construction interviewer that the reason you are changing construction careers is that you can no longer work in the old line of work and you have developed new interests -- part of the blessing of the injury. Accentuate the positive.