Here’s a word of warning for people who exercise on treadmills: Watch your step!

It turns out that treadmills are not only the most popular piece of exercise equipment people have in their homes; they are also the most dangerous.

According to the Consumer Product Safety Commission, some 19,000 people incurred injuries on treadmills serious enough to go to the emergency room in 2009. Almost 6,000 of those serious injuries were to children.

The injuries included broken bones, amputated fingers and concussions.

The 4-year-old daughter of former boxing champion Mike Tyson was killed in 2009 when she was strangled by a cord on the treadmill in his home.

One avid exerciser who found out first hand that treadmills can be hazardous to one’s health is Julie Osborne, who described her experience to Susan Koeppen of “The Early Show” on CBS TV.

Osborne told Koeppen that she “never experienced any kind of pain like” she did when she got three fingers stuck between the frame and the running track on her machine as she tried to step back on with the belt still running.