The whole chore seems pretty mellow to me, I must be doing it wrong.
Even though raking does not utilize power tools or sharp blades, it can still cause injuries. According to 2006 U.S. Consumer Products Safety Commission statistics, more than 76,000 people were treated in hospital emergency rooms, doctors' offices, clinics and other medical settings for injuries related to non-powered garden tools, including rakes.
"Many people consider raking just another chore, but it requires a lot more reaching, bending and lifting than most odd jobs," says Daryll C. Dykes, MD, PhD, orthopaedic surgeon and spokesperson for the Academy. "Raking should be treated like any other vigorous exercise. People should pay close attention to their arms and backs, being careful not to reach or stretch too far."
Seriously, though, there are good recommendations to warm up before raking to prevent such injuries.