Fitting In: Industrial Ergonomics for Municipalities
The U.S. Department of Labor defines ergonomics as the science of "fitting workplace conditions and job demands to the capabilities of the working population." Effective and successful fits assure high productivity, avoidance of illness and injury risks and increased satisfaction among the workforce.
The goal of a successful ergonomics program is to decrease injuries by reducing the risk of musculoskeletal disorders. Common examples of musculoskeletal disorders include muscle strains along with back, shoulder, leg, arm and hand injuries.
Exposure to Risk
Industrial ergonomics focuses on workers with jobs which commonly require manual labor such as lifting, use of machinery and regular use of power and hand tools. Risk factors for injury in the industrial setting include repetitive, forceful or prolonged exertions, frequent or heavy lifting, pushing, pulling or carrying of heavy objects and prolonged awkward postures. Vibration plus cold and hot working conditions can also increase the risk of injuries.
Jobs presenting multiple risk factors will have a higher probability of causing a musculoskeletal problem. Intensity, frequency and duration of physical demands combined with the physical fitness of individual workers are also major factors that influence injury risks in industrial settings.
In the municipal workplace, public works employees, firefighters and facility maintenance workers are among some of the groups whose job requirements involve increased exposure to industrial ergonomic risk factors. In fact, a study conducted at the University of Iowa found high rates of reported problems in the low backs, knees, shoulders, hands and wrists of employees in these groups.
Careful Tool Selection
According to the National Institute for Occupational Health and Safety, some tools are advertised as "ergonomic" or designed with ergonomic features. A tool becomes "ergonomic" only when it fits the task you are performing, and it fits your hand without causing awkward postures, harmful contact pressures or other safety and health risks.
If you use a tool in a way it was not intended or does not fit your hand, you might develop an injury like carpal tunnel syndrome, tendonitis or muscle strain. These injuries do not happen because of a single event, such as a fall. Instead, they result from repetitive movements that are performed over time, or for a long period of time, which may result in damage to muscles, tendons, nerves, ligaments, joints, cartilage, spinal discs or blood vessels.
Tools which vibrate need to be evaluated for ergonomic safety. Vibration exposure over time can lead to problems. Excessive vibration can damage the blood vessels and nerves in the hands. Examples of tools for which vibration levels, also known as "acceleration levels," need to be evaluated include chainsaws, jackhammers, drills, grinders, lawnmowers and trimmers.
Job factors to consider related to vibrating tool usage include the amount of time and the manner in which the tool is used. Check with manufacturers to ensure tools have safe hand-arm vibration ratings. Rest and recovery breaks should be taken when performing jobs with long durations. Additional steps that may reduce risk of injury include wearing vibration-reducing gloves, keeping hands warm and maintaining light but secure grips when using vibrating tools.
Tools for which ergonomic design should be considered include those that cut, pinch, grip, strike and drive. Examples include pliers, snips, drills, screwdrivers, wrenches and nut drivers. In general, hand tools should be easy to use with comfortable grips. They should not dig into the hand or require wrists to be held in awkward positions.
Select tools with power (wider and softer) grips. Foam can be used to cushion handles and improve grip. Choose sprayers, drills and other tools with larger triggers that can be operated with multiple fingers to avoid unnecessary stress on one finger. Avoid using bare hands to hammer or pound anything into place.
Avoid Unnecessary Strain
Performing overhead work such as painting and drilling can increase risk for problems, especially in the shoulders, neck and back. This type of work often requires keeping the arms and neck in fixed, awkward, hard-to-hold positions. Excessive force is also commonly required to push upward and hold heavy tools above the shoulders. Use of lifts and ladders, bit extensions for drills and telescoping handles allow tools to be held below shoulder height and closer to the body to avoid unnecessary strain.
At many job sites, workers spend substantial amounts of time lifting, carrying, holding, pushing or pulling loads of material. Back problems are common with this type of work. Motions such as bending, twisting and reaching while lifting increase risk for back injury. Sitting or standing too long in one position is another contributing factor to back strain.
Handling materials continuously and for long periods of time places constant stress on the bodyespecially the back. When handling large amounts of materials like lumber or aggregates such as loam, sand and gravel, it can help to stage deliveries in close proximity to the job site and use mechanical loaders to avoid unnecessary handling. At the shop, store frequently used materials on shelves at waist height to avoid unwarranted reaching and bending. Try not to place heavier objects overhead, but they don't have to be located on the floor, either. Place them at a level which makes them easier to handle and, when possible, use mechanical lifting equipment.
Most importantly, workers need to practice proper body mechanics and safe lifting techniques to avoid injuries when performing jobs requiring manual labor. These techniques include the following:
- Bend at the knees and not with the back.
- Lift with the legs.
- Hold loads close to the body.
- Contract stomach muscles.
- Keep the back aligned and upright.
- Avoid twisting.
In addition to safe body mechanics, it is important to acknowledge that general health and conditioning significantly impact the condition of our backs. Positive factors to consider include regular physical fitness, good nutrition, adequate rest and awareness of physical limitations.
New Hampshire Local Government Center's Health and Safety team offers a number of services to help industrial workers stay injury free. Available trainings include Back Injury Prevention, Safe Body Mechanics, Personal Protective Equipment and Preventing Falls. Ergonomic assessments and building safety inspections are also available for LGC Risk Pool Groups with Workers' Compensation Program and Property-Liability Trust coverage.
Kevin Flanagan, MPH, is a Health and Safety Advisor for New Hampshire Local Government Center and an Ergonomics Assessment Specialist. To book ergonomics assessments for your group, contact your LGC Health and Safety Advisor.