Often younger people in their 30's in very physical jobs are at the highest risk for disabilities that can affect them for short or long periods of time. Often disability insurance is not considered by these highest risk groups simply because they see it as an insurance for older people.
When considering disability insurance it is important to understand how it may or may not affect other benefits you may be eligible to receive such as SSI., workman's compensation or even unemployment benefits. Talk to your employer and insurance agent and find out what is the best combination for your individual needs.