TEMPERANCE, Mich. -

Dozens of cheering supporters released balloons as a Michigan teenager began a 40-mile journey on foot with a special cargo strapped to his back.

His 7-year-old brother.

Fourteen-year-old Hunter Gandee started walking from Bedford Junior High School on Saturday. Hunter's brother, Braden Gandee, who has cerebral palsy, was on his back.

The trek will end Sunday at the University of Michigan in Ann Arbor.

Because of his brother, Hunter adopted awareness of cerebral palsy as a personal cause.

During a pre-walk pep rally in the school gym, Braden told those in the crowd that their support "means so much." And Hunter said it would "push us through" the walk.

Hunter is a 155-pound wrestler. His brother weighs just over 50 pounds. The Gandees live in Temperance, near the Ohio boundary.