ABSTRACT
There are three types of controls that ergonomics practitioners can implement to reduce the risk of
musculoskeletal disorders (MSDs) and acute trauma in the workplace. These controls are engineering
controls, administrative controls, and personal protective equipment (Chengular et al., 2004). Engineering
controls, which are usually the most effective long-term controls to reduce risk of MSDs, are modifications to
the workplace that fundamentally change workers’ exposure through physical modifications to the work or
workplace (AFMA, 2003). The purpose of engineering controls is to significantly reduce the physical stressors
of a job through fundamental changes, without relying upon the compliance of a worker, because the controls
largely do not give the worker the option of performing the work in a different way. Some engineering control
are listed below. Refer to Cohen et al. (1997) for an extensive list of engineering controls:
. Changing tools or modifying features of hand or power tools, such as adding more comfortable
handles, changing the angle of handles (pistol grip for horizontal exertions and in-line grip for
vertical movements), changing the torque, reducing the weight of the tool, moving the tool’s
center of mass so it is above the center of the hand, etc. . Changing the manufacturing or production process to reduce risk factors of MSDs, such as new
technology that orients parts so that the worker does not have to lean or reach or new processes
that reduce exertions and motions that stress the same body parts . Changing the sequence of assembly or operations to reduce repetitive manual work. Typically,
these changes often enhance productivity . Adjusting the pace of work, either through the speed of the line or quotas, to reduce repetitiveness
of the work . Changing the method by which parts and materials are transported. For example, fully automatic
lift systems or mechanical assistive systems can eliminate the physical stress from manual lifting
. Removing physical obstructions or impediments to work flow, which can reduce awkward postures
and force exertions . Adding antifatigue mats to flooring for workers who have to stand in the same place all day . Purchasing high-quality carts or trolleys that have well-lubricated rolling mechanisms and easy
steering to reduce pushing and pulling forces
Administrative controls are changes to the work organization and methods of performing work that do
not involve physical changes. Frequently, these controls require formal education and training of workers
and management. Administrative controls are not fundamental changes to the workplace, as are engin-
eering controls. Examples of administrative controls are implementing rest breaks, rotating workers,
exercise programs, encouraging employees to keep their wrists in a neutral posture while doing
manual work, and encouraging workers to perform lifting tasks with good body mechanics —
keeping the load as close as possible to the body and using the legs to lift (AFMA, 2003). Administrative
controls require the compliance of the employee to implement the control and vigilance of the employer;
noncompliance of the worker may not reduce the exposure to risk of MSDs and is the main weakness of
administrative controls. For example, a worker who is scheduled to rotate jobs may stay at one job longer
than recommended (for a variety of reasons) and thus not benefit from the variable musculoskeletal
loading job rotation offers. Although some administrative controls can be very effective, such as
worker rotation, administrative controls are generally less effective than engineering controls. In many
situations, administrative controls require the employer to vigilantly enforce the controls in order for
them to be effective.
