From The Ergoweb® Learning Center

How to design equipment to prevent Back Injuries

Dan MacLeod, CPE, MA, MPH

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Back injury risks

Back injuries are the most common and consequential type of musculoskeletal injury in general industry. Prevention can involve a number of factors, including personal wellness and work habits. The information on this page focuses on ways to improve equipment and workstations to reduce strain on the back.

The following are common categories of issues that can create back problems in production settings. These categories serve two purposes: (a) provide a list of issues to consider, and (b) provide a structure to help avoid creating a single large jumble of solutions. However, many of the solutions could actually be placed in multiple categories. Consequently, it is best to browse through all the topics to see the full array of potential solutions.

Also make sure to read the basic principles of ergonomics, as well as cautions and avoiding common errors.

Improve working posture

Awkward working positions can increase the strain on the back in two ways:

  • Add the weight of the upper torso when bending and lifting
  • Extend loads away from the body, increasing the horizontal distance from the spine

Thus, evaluate tasks by look for bent or twisted postures of the back, then review the various options for improvement. Read the background material on the optimal or neutral postures to understand your objectives.

Height of materials

Many industrial workplaces use or create stacks of materials on pallets or in large containers. In these situations, the height changes as items are removed or added. Thus, at times the materials can be too low, which creates a strain on the back when bending to handling the items.

The general strategy in these situations is to find ways adjust the height of the material to keep it at a good working level. The following topics provide overviews of the different types of equipment that are typically used in these situations

HtLift HtTilter
Container and pallet lifts Tilters

 

HtDumper HtContainer
Dumpers Large containers

 

Height of work

The work being performed should be at a height that enables the employee to work upright, without bending. Normally, this is about elbow height (although there are exceptions — see Heights). Note that this height is for the item being worked on, not the work surface. If the size of the items vary, or if employees of different statures us the same workstation, then the work height might best be adjustable.

HtAdjust HtSlant HtPlatform
Height adjustment Slanted workstations Standing platforms

Horizontal reaches

Quite often, the reason that people bend their backs while working is that items are too far away. There are a number of different appoaches for moving items closer.

 

HzSize HzFixture HzStorage
Work surface size Floor-based fixtures/work positioners Storage

 

Sitting

Constant sitting can create strain on the back in unforseen ways. Particular issues are lumbar support and ability to adjust the height of chairs. Additionally, staying in the same position for long periods can be a contributing factor.

 

Sit1 Sit2
Seating Sit-stand

 

Standing

Excessive standing does not normally create as big a risk for back injuries as awkward postures or heavy loads. However, there are issues that can contribute to the overall strain on the back.

 

Stand1 Stand2
Flooring Foot rests

 

Twisting

A number of different factors may cause twisting, including the following:

 

Twist1 Twist2 Twist3
Clearance Layout Visual access

 

Reduce exertion related to the load

Lifting/Carrying

There are many techniques that can be used to eliminate the need to lift or carry a load:

 

Lift1 Lift2 Lift3
Conveyors Slides Conveyor gates
Lift4 Lift5 OLYMPUS DIGITAL CAMERA
Carts Lifter-transporters Lift trucks
Lift7 Lift8
Hoists Manipulators

 

 

Push/Pull

Carts and other pieces of equipment with wheels are good solutions to eliminate the need to lift and/or carry.  But sometimes, the loads are still heavy to move.  Issues and options include the following:

 

Push1 Push2  Push3
Wheels Air casters Tuggers

 

Item itself

reduce size, weight,

add handholds

 

 

Static load

heights, reaches

Motions

Eliminate the need to lift – many of the above

Improve area layouts – distances carried, frequency carried

 

Environmental

Vibration Shock Temperature extremes