PHYSICAL TASKS:JOB ANALYSIS AND DESIGN

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JOB ANALYSIS AND DESIGN

According to ANSI Z-365 (1995), job analysis and design serve two common purposes:

1. To identify potential work-related risk factors associated with musculoskeletal disorders after they are reported

2. To assist in identifying work-related factors associated with musculoskeletal disorders before they occur

Detailed job analysis consists of analyzing the job at the element or micro-level. These analyses involve breaking down the job into component actions, measuring and quantifying risk factors, and identifying the problems and conditions contributing to each risk factor. Job surveys, on the other hand, are used for establishing work relatedness, prioritizing jobs for further analysis, or proactive risk factors surveillance. Such survey methods may include facility walk-throughs, worker interviews, risk-factor checklists, and team problem-solving approaches.

Risk Factors and Definitions

The risk factors are job attributes or exposures that increase probability of the occurrence of work- related musculoskeletal disorders. The WRMD risk factors are present at varying levels for different jobs and tasks. It should be noted that these risk factors are not necessarily causation factors of WRMDs. Also, the mere presence of a risk factor does not necessarily mean that a worker performing a job is at excessive risk of injury. (The relationship between physical stresses and WRMD risk factors is shown in Table 22.) Generally, the greater the exposure to a single risk factor or combination of factors, the greater the risk of a WRMD. Furthermore, the more risk factors that are present, the higher the risk of injury. According to ANSI Z-365 (1995), this interaction between risk factors may have a multiplicative rather than an additive effect. However, these risk factors may pose minimal risk of injury if sufficient exposure is not present or if sufficient recovery time is provided. It is known that changes in the levels of risk factors will result in changes in the risk of WRMDs. Therefore, a reduction in WRMD risk factors should reduce the risk for WRMDs. Figure 18 shows the flow chart for the ergonomics rule for control of MSDs at the workplace proposed by OSHA (2000).

Work Organization Risk Factors

The mechanisms by which poor work organization could increase the risk for WUEDs include mod- ifying the extent of exposure to other risk factors (physical and environmental) and modifying the

Physical Tasks Analysis, Design, and-0057

stress response of the individual, thereby increasing the risk associated with a given level of exposure (ANSI 1995). Specific work organization factors that have been shown to fall into at least one of these categories include (but are not limited to):

1. Wage incentives

2. Machine-paced work

3. Workplace conflicts of many types

4. Absence of worker decision latitude

5. Time pressures and work overload

6. Unaccustomed work during training periods or after return from long-term leave

Procedures for Job Analysis and Design

Job analysis should be performed at a sufficient level of detail to identify potential work-related risk factors associated with WRMDs and include the following steps:

1. Collection of the pertinent information for all jobs and associated work methods

2. Interview of the representative sample of the affected workers

3. Breakdown of the jobs into tasks or elements

4. Description of the component actions of each task or element

5. Measurement and quantification of WRMD risk factors

6. Identification of the risk factors for each task or element

7. Identification of the problems contributing to risk factors

8. Summary of the problem areas and needs for intervention for all jobs and associated new work methods

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