Safe Lifting and Body Mechanics

Strains and sprains are among the most common work injuries in nearly every trade, and they rarely come from one dramatic event. Most build up over thousands of lifts, reaches and twists until something gives. Body mechanics means using your body in ways that keep the load on your legs and away from your spine and small joints. It costs a few seconds per lift and can spare you years of pain.

What You Will Be Able to Do

• Name the risk factors that lead to musculoskeletal disorders.
• Size up a load and decide whether to lift it, split it, get help or use equipment.
• Lift, carry and set down a load using the correct steps.
• Choose push over pull and explain why.
• Spot early warning signs and act on them.

What Actually Hurts You

A musculoskeletal disorder (MSD) is an injury to muscles, tendons, nerves, joints or spinal discs. Carpal tunnel syndrome, tendonitis, a herniated disc and a rotator cuff tear are all MSDs. The main risk factors are:

Risk adds up when factors combine. A 30-pound box lifted once from a table is easy. The same box lifted 200 times a shift from the floor, with a twist, is a likely injury.

Why Distance Matters More Than You Think

NIOSH, the federal research agency for worker safety, developed a lifting equation that starts from a 51-pound limit. That number applies only under ideal conditions: the load is close to your body, at about waist height, lifted straight up, infrequently, with a good grip. Every condition that gets worse lowers the limit. It is a planning tool, not an OSHA rule, and OSHA has no single legal lifting limit.

Worked example: The equation includes a factor for how far the load sits out in front of your ankles. It is 10 divided by the distance in inches.

1. A load held 10 inches out: 10 / 10 = 1.0. The limit stays at 51 pounds.
2. A load held 20 inches out, say across a bin edge: 10 / 20 = 0.5.
3. 51 x 0.5 = about 25 pounds, before counting any twist, height or frequency.

So simply reaching out cuts what you can safely lift by half. That is the reason to get close to the load.

Before You Lift

1. Size up the load. Tip it or push it to feel the weight. Check the label. Look for shifting contents, sharp edges and grease.
2. Plan the route. Walk it if you need to. Clear trip hazards and open doors first.
3. Plan the landing. Know where it is going and make sure there is room.
4. Change the job if you can. Use a cart, dolly, pallet jack, hoist or conveyor. Break the load into smaller loads. Store heavy items between knee and shoulder height, so nobody has to lift from the floor.
5. Get help if the load is heavy, bulky, or you cannot see over it.

How to Lift

1. Stand close to the load with your feet about shoulder width apart, one foot slightly ahead if that helps your balance.
2. Bend at your hips and knees and keep your back in its natural curve. Squat rather than stoop.
3. Get a firm grip with your whole hand, not just your fingers.
4. Tighten your stomach muscles.
5. Keep the load against your body and lift smoothly with your legs. Do not jerk it.
6. Keep your head up and look ahead.
7. To turn, move your feet. Do not twist at the waist.
8. Set the load down the same way, bending at your hips and knees, and keep your fingers out from underneath.

Warning: Twisting while you lift or set down a load is one of the fastest ways to injure a disc. Pick up the load, then step around.

Team Lifts

Two people can handle more than one, but only when they work as a team. Pick one person to call the moves. Match people of similar height where you can. Agree on the route and the landing first. Lift, walk and lower on the count. If one person stops, everyone stops.

Overhead and Low Work

• Use a stable step or platform to bring work below shoulder height.
• Do not hold a load overhead while you work. Support it with a jack, a lift or a helper.
• Kneel on a pad or use knee pads for low work. Rest one knee, then switch.
• Move the work to you. A bench or a stand at waist height beats bending all day.

Pushing, Pulling and Carrying

Push when you can. You can use your body weight, you can see where you are going, and you are less likely to strain your lower back or trip backward.

• Keep your arms close and your elbows bent, and lean in.
• Start slowly, because getting a load moving takes the most force.
• Keep carts and hand trucks maintained, since a bad wheel can double the force needed.
• Check the floor for cracks, thresholds and ramps.
• Carry one load at a time. Use both hands, and balance a load between sides if you can. A heavy bag on one shoulder puts a twist in your spine.

Protect Your Hands, Wrists and Shoulders

• Keep your wrists straight. Pick a tool with the right handle angle for the job, such as a pistol grip for a vertical surface and an inline grip for a flat one.
• Do not grip harder than you need to, and keep cutting tools sharp.
• Use your whole arm, not just the wrist, for repeated force.
• Take short breaks or trade tasks with someone during repeated work. A few seconds of rest helps more than a long break after you are already sore.

What About Back Belts and Stretching

NIOSH has not found enough evidence that back belts prevent injury, and they can give you a false sense of safety. Follow your employer's policy, but do not lift more because you have one on. Warming up can help you get moving, but it does not change what a bad lift does to your back.

Lifting People Is Different

A person is not a box. People shift, resist and fall without warning. In care settings, use the lift equipment and transfer methods your training covers, and do not try to catch a falling person with your back.

Early Warning Signs

Report these at the start. Do not wait for them to go away.

• Pain that lasts after your shift or wakes you at night.
• Numbness or tingling in your fingers or hands.
• Weak grip, or dropping things.
• Swelling, stiffness or a clicking joint.
• Pain that runs down your leg.

An early report leads to a small fix, such as a change in the setup. A late report can mean surgery and a lost career. If you are having pain, tell your supervisor and get it looked at.

Common Mistakes

Check Your Understanding

1. You need to take a 40-pound box from the back of a low shelf, with your arms fully out. What should you change?

Pull the box toward you first, then get close and squat. If it cannot be moved close, get help or a tool. A load that far out is far past its safe limit, even though it is under 51 pounds.

2. You and a coworker have to move a long, heavy cabinet through two doors. What should happen first?

Clear and open the route, agree on who calls the moves, and consider a dolly. Decide where you will set it down. Then lift together on a count.

3. You must move a heavy cart with a stuck wheel across a yard. Push or pull?

Push it, after fixing or replacing the bad wheel if you can. Pushing lets you use your body weight and see where you are going.

4. Your fingers have been tingling at night for a week since you started a new task. What do you do?

Report it now and get it checked. Tingling is an early sign of nerve trouble, and the task may need a change.

Key Takeaways

• Most back, shoulder and wrist injuries build up over time from force, repetition, posture, contact stress, vibration and duration.
• The 51-pound NIOSH figure applies only under ideal conditions. Real lifts have a lower limit.
• Get close, bend at the hips and knees, keep the load against your body, and move your feet to turn.
• Use equipment, split the load or get help before you rely on muscle.
• Push rather than pull.
• Report early symptoms while they are still easy to fix.