If considered disabled and was employed as a truck driver what is considered gainful emplotment?

Assess the economic facts: your earnings before the disability, your living expenses such as housing, utilities, taxes, etc (not discretionary i.e., premium cable channels, restaurant dining, etc), and your earnings after the disability. Now do the math. Obviously the cost of your living does not change. The hard reality is only your income changes; and we know this is less due to one's handicapped skills. The gap that has to filled to meet your needs means you need "gainful employment" to eliminate the deficit spending situation. Gainful employment is much easier said than done unless you are a Stock Market guru, an exceptionally creative talent, a famous artistic, a supreme intellectual, a political power mogul, or want to slave at 2 or 3 jobs over 40 hours a week. When you have income that covers your needed expenses or more you are now "gainfully employed". If your gainful employment generates more income than your expenses you now can enjoy "discretionary income". The discretionary income can be spent on luxuries such as dining out, vacations, memorable gifts, premium cable channels, a new car, etc. Some gainfully employed earners prefer to save their discretionary income.