Ergonomics Job Hazard Analysis

Efforts to identify jobs or tasks having known risk factors for musculoskeletal problems can provide the groundwork for changes aimed at risk reduction. Even without clear medical evidence, screening jobs for musculoskeletal risk factors can offer a basis for early interventions.

An effective identification method is the Ergonomics Job Hazard Analysis which breaks a job into its various elements or actions, describes them, measures and quantifies the ergonomics risk factors inherent in the elements, identifies conditions contributing to the risk factors, and determines corrective measures.

Job analyses are usually done by persons with considerable experience and training in these areas. While most job analyses have common approaches, such as a focus on the same set of risk factors described above, no "standard" protocol exists for conducting a job analysis to assess ergonomic hazards.

Most job analyses have several common steps:

• A complete description of the job is obtained.
• Employees are often interviewed in order to determine if the way the job is done changes over time.
• During the job analysis, the job is divided into a number of discrete tasks.
• Each task is then studied to determine the specific risk factors that occur during the task.
• Sometimes each risk factor is evaluated in terms of its magnitude, the number of times it occurs during the task, and how long the risk factor lasts each time it occurs.

The tasks of most jobs can be described in terms of:

• The tools, equipment, machinery and materials used to perform the job. Their design can have enormous impact on the risk of injury.
• The workstation layout and physical environment. Establishes parameters and constraints on our posture, movement, etc.
• The task demands and organizational climate in which the work is performed. Works schedules, production quotas, psychosocial support can create fatigue, anxiety, and low morale that may increase the probability of injury or illness.

More definitive procedures for collecting information on these components can include the following:

• Observing the workers performing the tasks in order to furnish time-activity analysis and job or task cycle data; videotaping the workers is typically done for this purpose
• Still photos of work postures, workstation layouts, tools, etc., to illustrate the job
• Workstation measurements (e.g., work surface heights, reach distances)
• Measuring tool handle sizes, weighing tools and parts, and measuring tool vibration and part dimensions
• Determining characteristics of work surfaces such as slip resistance, hardness, and surface edges
• Measuring exposures to heat, cold, and whole body vibration
• Biomechanical calculations (e.g., muscle force required to accomplish a task or the pressure put on a spinal disc based on the weight of a load lifted, pulled, or pushed)
• Physiological measures (e.g., oxygen consumption, heart rate)
• Special questionnaires, interviews, and subjective rating procedures to determine the amount of perceived exertion and the psychological factors influencing work performance

Setting Priorities

Jobs associated with cases of musculoskeletal problems deserve the highest consideration in follow-up efforts to identify ergonomics risk factors and implement control actions. Jobs in which current cases have been identified should receive immediate attention, followed by those in which past records have noted a high incidence or severity of MSDs despite the lack of current cases.

Priority for job analysis and intervention should be given to those jobs:

• In which most people are affected or in which work method changes are going to be taking place anyway.
• Associated with employee reports of fatigue and discomfort.
• Where screening efforts suggest the presence of significant risk factors for musculoskeletal disorders.

Ratings of high or extreme levels of risk factors, especially occurring in combination, may indicate a need for control actions. While appearing last in the priority order, taking steps to reduce apparent risk factors for musculoskeletal disorders is an important proactive approach.

Source: OSHA

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