For nurses, it's a job almost as unpleasant as changing bedpans: moving heavy patients from stretchers to beds and back again. With the average U.S. nurse now in her mid-40s and hospitalized Americans growing more supersized each year, patient-schlepping is putting more nurses in danger of being hospitalized themselves. The American Nurses Association estimates 52 percent of its members complain of chronic back pain; according to the Bureau of Labor Statistics, nurses are more at risk for back strains than construction workers. So at the ANA's biennial convention in Minneapolis this week, nurses will discuss a key lobbying goal: getting more hospitals to enact "no lift" policies requiring that machines, rather than nurses, be responsible for "patient handling."

Many hospitals that specialize in bariatric surgery on obese patients are already equipped with hydraulic equipment--imagine a small crane with a sling on it--for that job. The technology is also widely used in Europe. But in the past year, more U.S. hospitals have begun buying simpler devices: plastic air mattresses with small holes on the bottom. The air mattress slips under the patient, a small pump inflates it and air escapes through the holes, reducing the friction as the patient is pulled between beds. "It's like an upside-down air-hockey table, and the patient's the puck," says Dave Davis of HoverTech International. James Weedling of rival Patient Transfer Industries says: "What's really driving the product now is Worker Compensation claims."

Proponents say the $3,000 devices pay for themselves in a matter of months. Says Sandy Wise of Novation, a Texas firm that helps hospitals buy equipment: "This is a supply that will become a necessity." If they weren't so pricey and electrified, they also look like they'd be fun at a pool party.