Backpacks on a roll.(wheeled school backpacks)(Buyers Guide)

Backpacks on wheels are pitched as a solution to the heavy load of textbooks many kids carry to and from school. More than 3,400 children ages 5 to 14 visited emergency rooms with backpack-related injuries in 1999, the latest year for which figures are available, says the Consumer Product Safety Commission. Strains and sprains accounted for many of those injuries. According to the American Academy of Orthopaedic Surgeons, children should not carry more than 20 percent of their own weight on their back.

We tested eight rolling backpacks, $20 to $90. Most were nylon or polyester. When empty, most weighed 2 to 4 pounds (compared with 1 to 2 pounds for most conventional backpacks); some were 5 or 6 pounds. Weight is an issue because even rolling backpacks sometimes need to be carried.

To see how well they'd hold up under normal use and abuse, we put each in our luggage tumbler, a big spinning drum, for 500 cycles. We also asked 18 students, ages 8 to 12, to try them out and assess handle comfort, ease of steering, wheel noise, and how comfortable they were to carry on their back. (Rolling backpacks are pitched to this age group; teens tend to prefer conventional backpacks, manufacturers say.)

Backpack models change constantly. Some we tested have a slightly different look now; a few others have been discontinued. But what we learned from our tests serves as a useful shopping guide no matter which brands and models you encounter.

THE BEST

The Olympia Leather Trim Rolling Backpack, $20, from Macy's, was among the least expensive bags, did very well in our durability tests, and got high marks from student testers, who thought it looked cool, too. This style is being phased out, although the same bag without leather, model RP-1090, is $30.

The Spalding Crosswalk Wheeled Backpack 717072, $30, from Kmart, did very well in our durability tests. Some students found it awkward to steer, however.(Model 808072 has now replaced it.)