Alton Churchill from Georgia has. So he made a guard to protect his legs. The material is used to insulate hot water pipes and has a slit on one side so it'll fit over the pipe. You can find it at home improvement stores. To hold it securely in place, Alton used strips of duct tape.
Some wheelbarrows have a wide bar across the back instead of a thin support.
If yours has the wide bar, the pipe insulation may not fit over it. But don't worry. Instead, wrap it with a section of thick carpeting. You can hold it in place with duct tape, too. You still might bump your shins, but the padding will help soften the blow considerably.