When Size Lies
by Savanah Mickey, LAT, ATC, CEAS
Lifting is inevitable in everyday life, whether you are lifting material to set up for the workday, or you’re lifting the dog over the baby gate to go outside, or perhaps lifting a pitcher of sweet tea to have with dinner after a long day. We’re constantly lifting and moving things in work and daily life, but what sets all of these examples apart is the size, weight, and position of what we’re moving. Before any lift, it’s important to assess factors like weight, frequency, height, distance from the body, and how long the load is held.
Size-Weight Illusion
Part of this risk appraisal comes down to our initial impression of what we are about to lift. It’s easy to assume that larger objects will be lighter and easier to lift. This theory is the size-weight illusion, in which it states that we cannot just rely on this initial appraisal and should instead use a preliminary lifting phase to gauge whether we need to do a team lift or recruit more muscles for the weight we are attempting to move. This initial lifting phase includes engaging the core, pushing the hips back, bending at the knees, and lightly test-lifting the object a few inches to determine if we can continue this lift safely.
Our experience in the world around us helps with the general appraisal of whether something is going to be 5lbs or 55lbs. Theories suggest that if we don’t know the weight of an object, we’re likely to have an increase in heart rate and muscle activation (specifically in the erector spinae and both trapezius muscles) before attempting the lift for the first time. This is why it’s important to have a log or coding system of the weights associated in the workplace so that everyone knows how much force to apply in their lift. As the weight increases, so does the risk factor associated with the lift. This makes the position of the object critical, as well.
Move It To The Green Zone
The safest area to lift is in the Green Zone. This is the area above the knee, below the shoulders, and about a foot out in front of the body. If something is below the Green Zone, recruit more muscles from the lower body by bending the knees, pushing the hips back, and keeping the item close to the body. If something is above the Green Zone or over the shoulder, push the item up slightly with both hands making sure you keep your shoulder blades pinched and your elbows in. With both examples, assess the weight and determine if it’s safe to move the material before doing so. Moving the object into the Green Zone and a light test-lift should be the first considerations, or ask someone for help with attention to weight and awkwardness of the object’s size.
Teamwork Prevents
How do we decrease our risk when lifting either at home or work? Alternate between heavy and light lifting tasks, if possible, to give your body a break from heavy loads. If you know the size and weight of the item you are moving, it might be easier to move because you can recruit the right amount of muscles and force. But if you are lifting something awkward (perhaps a pet or child that likes to wiggle), continue to size up the load and make ergonomic adjustments when needed. If you are lifting material at work and have questions about the size, weight, or ergonomics of the lift you are about to perform, please contact your Injury Prevention Specialist. They’ll be able to assess the risk factors associated with the lift and how to position the body in the safest way to decrease the risk of musculoskeletal fatigue or discomfort.
Savanah Mickey, MS, LAT, ATC, CEAS || Savanah has 5 years of athletic training experience across the military and industrial settings. When she isn’t assisting industrial athletes in western Kentucky, she enjoys golfing, working out, taking her cat for a walk, and baking.
Be sure to check out our other blogs for further injury prevention education and tips for the industrial athlete from Work Right NW!