4.21 Manual Lifting

Safety, Health, and Environmental Manual

The following are basic guidelines for manual lifting. The overriding consideration is to design the job to fit the worker. Injuries occur when there is a difference between the strength of the worker and the strength required to do the job. Managers and supervisors should assign workers to tasks they can handle.

4.21.1 General Lifting Guidelines

Use the following guidelines for general lifting:

  • Observe the following weight requirements:

    • Loads less than 30 pounds (14 kg). These loads are generally acceptable unless the lift involves frequent lifting, awkward and constrained postures, poor grip, or twisting.

    • Loads of 30–50 pounds (14–23 kg). These lifts are marginally hazardous and have an increased risk of injury for some workers. Protect workers by allowing them to select the loads they lift, conducting conditioning exercises, or reducing the amount lifted. Remember that frequent lifting, awkward and constrained postures, poor grip, and twisting will make the lifting hazard more severe.

    • Loads heavier than 50 pounds (23 kg). These lifts are generally considered hazardous. Most workers would be at risk of injury. In addition to the guidelines above, use mechanical lifting devices, such as forklifts, scissor lifts, or pallet jacks. If not possible, use a multiple-person lifting team.

  • Reduce the horizontal distance between you and the load when lifting it, and keep it as close to waist height as possible.

  • Lift slowly and evenly; don’t jerk.

  • If possible, avoid lifting loads from the floor or from over the head. Loads generate the least stress on the back when lifted from knuckle height (the area where the knuckles are when the arms hang at the sides of the body).

  • If lifting from the floor, use the legs to lift, not the back. The load should not be overly bulky, and you should be able to get a good grip. Lift in a manner that will keep the load close to the body. If there is any question about your ability to lift the load, get help.

  • Avoid twisting the torso when lifting. Do not lift and then turn the upper body. This dramatically increases the chance of a back injury.

  • While carrying the load, always keep it close to the body.

4.21.2 Lifting Task Analysis

Managers, supervisors, and those lifting should consider the following when analyzing a lifting task:

  • Weight of the load

  • Height of the lift

  • Frequency of the lift

  • Posture during the lift

  • Grip on the load

Rotating employee assignments, providing a short break every hour, or using two-person lifting teams may be helpful in avoiding lifting injuries. Rotating assignments does not mean simply assigning an employee to another job; instead, it means assigning him or her to a job that utilizes a completely different muscle group from the ones exerted during lifting.

There are four basic kinds of lifts. Each is described as follows and assumes the load is held as close to the body as possible:

  1. Knuckle to shoulder height. This lift causes the least amount of stress on the spine. If possible, all lifts should be done this way.

  2. Floor or pallet height to knuckle. This lift causes more stress on the spine. Avoid this lift if possible by arranging the work area so workers may lift from knuckle height.

  3. Floor or pallet height to shoulder height. This lift generally causes the most stress on the spine. Avoid this lift if possible by arranging the work area so workers may lift from knuckle height.

  4. Shoulder height to above head. This lift puts stress on the spine and on arm and shoulder joints. Avoid if possible.

4.21.3 Conditioning Exercises

Compared to those who are not physically fit, those who are physically fit have fewer and less-severe back injuries. They also need less recovery time when injured. Workers can do conditioning exercises for their back muscles to become more physically fit. There are many trained people, such as physical therapists, nurses, physicians, and chiropractors, who can help with a conditioning program.

4.21.4 Abdominal Belts

There is scientific evidence that abdominal belts may not be an effective method of reducing back injuries. Abdominal belts are not recommended as protective equipment for manual lifting to prevent back injuries.

4.21.5 Training Programs

If you have many employees that do manual lifting, you may want to implement a comprehensive training program for manual lifting. There are many professionals who can help with a training program, such as physical therapists, nurses, physicians, chiropractors, ergonomists, and so forth. A comprehensive program for manual lifting should present a complete approach to back care, including safe lifting, strength, and physical fitness.

A training program for those whose jobs require manual lifting should include the following information:

  • Risks to health because of unskilled lifting

  • Body biomechanics

  • Effects on the body caused by lifting

  • The body’s strengths and weaknesses

  • How to avoid the unexpected physical factors that might contribute to lower-back pain

  • How to develop material-handling skills

  • How to use material-handling aids

Training resources on manual lifting are available on the Risk Management intranet site.