LAMBERTVILLE, Mich. -- A 15-year-old boy who last year walked 65 kilometres carrying his brother on his back to raise awareness about cerebral palsy has embarked on another such endeavour, this time 90 kilometres long.

Hunter Gandee was 14 years old last June when he carried then-7-year-old Braden on his back for two days. Cerebral palsy prevents Braden from walking without assistance. They travelled from their hometown of Temperance to Ann Arbor.

This year's "Cerebral Palsy Swagger" started Friday at a playground they raised money for at Braden's elementary. As of midday, the boys' mother Danielle Gandee says they're about a mile (1.6 kilometres) into their journey.

The walk ends Sunday in Ann Arbor. The family says it is an awareness project, not a fundraiser.