NIOSH sets 35-lb limit as the max for safe lifts

Manual lifts of patients aren't safe

A 180-pound patient is partially dependent, able to lift only about half his weight. He's in a chair and needs help standing. How many nurses would it take to help him safely if they have no lift equipment?

The answer: Three. A new recommended weight limit for manual lifting for health care workers, calculated from the National Institute for Occupational Safety and Health (NIOSH) Lifting Equation, sets the recommended maximum lift per nurse at 35 pounds.

If only two nurses helped the 180-pound partially dependent patient, they would each be lifting the equivalent of 45 pounds. Yet one nurse could help the patient with a sit-to-stand device, notes Tom Waters, PhD, research safety engineer in the NIOSH Division of Applied Research and Technology in Cincinnati.

"Almost all lifts of people are going to exceed the maximum recommended weight limit [for manual lifting]," says Waters, who created the original NIOSH lifting limit of 51 pounds for a static box under ideal conditions.

Needless to say, patients are not shaped like a box and usually aren't lifted under ideal conditions. An object should be held as close to the body as possible during a safe lift. In the health care calculations, however, Waters assumed that the health care worker would need to hold her arms at a 90-degree angle, with elbows by her side, for the best possible lift.

In fact, safe manual lifting is a matter of physics. The distance lifted, the vertical height, and the frequency of lifts are factors in addition to the weight. Lifting someone off the floor is one of the riskiest lifts that health care workers perform, Waters says.

Health care workers can use the lifting limit to determine when they need safety equipment. For example, if a nurse is holding a patient's leg to prepare it for surgery, how heavy is that lift? A leg weighs about 16% of total body weight, or about 39 pounds for a 250-pound person. If the patient weighs 250 pounds or more, the nurse will need to use equipment to lift the leg — or a second nurse will need to help hold it. "They need to have an awareness of the risk they're facing," says Nancy Hughes, MS, RN, director of the Center for Occupational and Environmental Health at the American Nurses Association in Silver Spring, MD.

When health care workers assess the need for lift equipment, they also need to estimate how much of the patient's weight they are bearing, she notes. "Just because there are two people [performing the lift] doesn't mean they're sharing the load equally," she says.

If a patient is combative or uncooperative, the lift limit would be even lower. The limit also applies to other lifts in health care, such as lifting heavy equipment, says Waters. "There is a maximum weight limit [for a safe lift]," he says. "If you exceed that, you are putting yourself at risk."

The limits are not only good for workers, but help the hospital's bottom line, notes Waters. "There is evidence that programs relying on lift equipment can pay for themselves by preventing back problems for nurses," he says.