“Lift with your legs, not your back” – you’ve heard this advice thousands of times. As a safety professional, you’ve probably taught this to others. But how effective is lifting training?
If you have ever tried to use the simple advice to “lift with your legs”, or tried teaching it to others, you have probably run into some problems – What about larger items that don’t fit between your legs in the standard “squatting” position? What if you can’t bend your knees due to the location of the item? Many common lifts have these characteristics – larger boxes, items on racks or shelves, patients in healthcare settings, objects in bins, etc.
Even if the lift lends itself to “lifting with the legs”, most employees will not consistently do it this way even if they have been trained. Try a quick experiment:
Stand up
Simon says, “Touch the floor!”
Did you squat while keeping your back in its natural S-curve? If you are like most people, you probably didn’t. It’s just too much work! At an ergonomics conference a couple of years ago, a presenter led our group through a slightly more scientific experiment (if you have any health problems, skip this one):
Take your resting heart rate
Stand up and touch the floor 10 times by bending over at the waist
Take your heart rate again
Sit back down and learn about ergonomics until your heart rate returns to normal
Stand up and touch the floor 10 times by squatting and keeping your back in its natural S-curve
Take your heart rate again
Most people (the presenter told us 85%) will have a higher heart rate after lifting with their legs than lifting with their back.
So even if you agree that lifting with your legs is safer, and even if the characteristics of your workspace allow it, many people will follow their human nature and simply bend their back. It’s easier – at least in the short term unless they get injured.
A lot of safety decisions and other decisions in our lives are made this way – definite short-term benefits win over possible long-term harm. Unless a supervisor is constantly reminding an employee to lift with their legs, which is an unrealistic expectation, most employees will resort to the “easiest” way to lift. Several published studies have confirmed this shortcoming of lifting training.
What is the solution to this problem? A comprehensive ergonomics program based on the hierarchy of safety controls. The most effective control is elimination of the hazard or substitution with something less hazardous. In the case of ergonomics, this would mean eliminating the need for the lift such as by rearranging the workflow. Engineering controls are the next most effective, such as powered lifting devices.
Training is considered an administrative control. Other administrative controls might be more effective than training, such as rotating employees to reduce the number of repetitions of the lift per employee. But this must be planned with expert advice to avoid simply injuring more employees. At the bottom of the hierarchy of controls, personal protective equipment such as back belts have not been proven to be effective for lifting.
Where does this leave training as a control for lifting? Training should be used to address the residual risk that remains after elimination, substitution and engineering controls have been implemented. Or it can be used as a short-term control until the others can be implemented due to budget or process constraints. When doing a cost-benefit analysis for an ergonomic improvement, remember that in addition to the direct and indirect cost of injuries, ergonomics often results in productivity improvements as well.
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