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IV. Program for Control of Work Related Disorders

4.1 Goals

The goal of an ergonomics program is to establish an ongoing mechanism for systematically identifying affected workers and jobs, for implementation of medical and work interventions, and for evaluating the effectiveness of those interventions.

4.2 The Process

4.2.1 The Plan

• Letter or memo to all persons in the organization
• Participation in program activities

Long term

• reduce CTD incidence and severity to background levels

Short term

• identify CTD trends
• identify new cases
• provide effective treatment for affected workers
• identify risk factors
• implement appropriate risk interventions

Tasks necessary to attain goals

• set up system to capture reported ctds
• train workers when to report health and work problems
• identify suitable medical resources
• conduct work place inspections
• review new job designs
• identify suitable work interventions
• etc.

Identify people who will perform the necessary tasks

• necessary skills
• necessary authority
• necessary parts of organization
• Training necessary to complete tasks and attain goals
  • management
  • supervisors
  • workers
  • safety & health
  • other

Schedule for completion of necessary tasks and goals

• time lines, GANT charts
• milestones
• Regular periodic program evaluation
• identify problems areas
• determine cause of problem
• resources?
• people?
• realistic goals?

A written program description should be tailored to fit each organization

• Written records of program activities and progress should be maintained for:
  • evaluation
  • paper trail
  • institutional memory
  • litigation

4.2.2 The Components (see Figure 5.1)

• A team
• Health surveillance
• Medical management
• Job analysis & improvement
• Training --- on-going
• References:
  • Aarås and Westgaard (1987)
  • Cohen, 1997
  • Israel, Schurman and Hugentobler 1992
  • Jones 1997
  • Liker, et al. 1984
  • Mansfield and Armstrong, 1997
  • McKenzie et al. 1985
  • Meyer et al. 1997
  • Moore and Garg 1997
  • Oxenburgh 1997
  • Pipinich, R. et al., 1993
  • NSC, 1997
  • Westgaard and Aarås (1985)

4. 3 Ergonomics Team

The causes of cumulative trauma disorders can be attributed to many job design factors and management policies at most work sites. Therefore, an ergonomics program should enlist the support of management, engineering, faciliti es, safety, medical and labor. It is recommended that an ergonomics team be established to:

• evaluate health data
• determine priorities for job analysis and intervention
• evaluate job analysis data and select intervention strategies
• evaluate program progress.

It may be desirable to establish teams in each production area of a work site. It is desirable to appoint a team coordinator to act as a liaison among team members.

Caution: Certain team functions may be a violation of the National Labor Relations Act (see: Bernstein 1993)

4. 4 Health Surveillance

4.4.1 Objectives

• Identify work areas, jobs, workers with greatest risk of cumulative trauma disorders
• Evaluate interventions and control program

4.4.2 Passive surveillance

sources of information:

OSHA logs - see Section I.J.2 Compensation reports Medical visits Personal medical records

Limitations: reporting may be influenced by:

• Worker and management attitudes
• Worker education
• Worker placement
• References: McKenzie et al. 1985; OSHA 1986, Putz-Anderson 1988; NSC, 1997; Westgaard and Aarås 1985.

4.4.3 Active surveillance

a. Health surveys

• Systematic health interviews & physical examinations
• Interviews and physical examinations (Fine & Silverstein 1988; Kuorinka et al. 1987; Waris et al., 1979; USDOL 1990; Katz et al. 1991)

b. Fatigue surveys

Comfort patterns (Scott and Huskisson 1976; Borg 1982; Price et al. 1983; Corlett & Bishop 1978; Habes 1984; Melzack 1975; Harms-Ringdahl 1986) --- See Appendix B

4.4.4 Statistics

a. Incidence rates

• New cases /200,000 work hours for each job, department, etc.:
• = Number of new cases / Number of work hrs. x 200,000
• Note: 2,000 hours is approximately the time worked by one worker in one year

b. Prevalence

• Percentage of people that are experiencing problems at a given time or during a given period
  

c. Identifying high risk groups

• Compare incidence rates of study group with reference group (see Hennekens 1987, p. 73-97):
• Relative Risk = Study Group Incidence Rate / Reference Group Incidence Rate
• Attributable Risk = Study Group Rate - Reference Group Rate
  • The study group is composed of persons from the department or job of interest.
  • The reference group is persons who do not perform hand intensive work. The study group and reference group should be matched or adjusted for age and gender differences.

d. Limitations

Small sample sizes & unstable work patterns often make it difficult to statistically validate findings

e. Example:

Upper limb musculoskeletal case reports for 6 months at an instrument engineering and manufacturing plant

1 - Cases per 100 workers per year
2 - Relative risk with respect to keying < 4 hours per day

f. References

• Checkoway, Pearce, and Crawford-Brown (1989)
• Hennekens and Buring (1987)
• Katz et al. ((1991)
• Putz-Anderson (1988)
• NSC 1997

4.5 Analysis of Jobs:

4.5.1 Objectives

Identify and rank specific risk factors for:

• Identifying ergonomic stresses
• Designing of interventions
• Evaluating of interventions

4.5.2 Methods

• Walk through inspection
• Checklist
• Observational Analysis
• Interviews, rankings and ratings
• Instrumental methods

4.5.3 Analysis Procedures

a. Document job attributes

Information needed to characterize job:

• Objective
• Work/production standards (Barnes 1980; Neibel 1986)
• Staffing
• Tasks
• Work methods (Barnes 1980; Neibel 1986)
• Workstation layout - dimensions, drawing, etc.
• Materials used
• Equipment used, e.g., tools, computers, fixtures, etc.
• Work environment

Sources of information

• Published reports, e.g., personnel, industrial engineering, facilities
• Inspection/observation
• video tapes
• Supervisor interviews
• Worker interviews

b. Assess Ergonomic Stresses

• Repeated and sustained static exertions from work standard and methods description and observation
• Work duration from production and payroll data
• Forceful exertions from inspection or work elements, estimation of loads and friction; adjustments for posture, mechanical aids, and gloves; instrumentation of tools; surface electromyography
• Localized mechanical stresses from inspection of work elements; related to force and area of contact
• Posture stresses from observations of jobs or films; instrumentation; analysis of work locations, orientations, tools, and anthropometry
• Vibration exposure from analysis of work, methods, tools and equipment; instrumentation
• Low temperature exposure from measurement of air, tool and material temperatures; adjustments for conductivity and protective equipment

List and rate ergonomic stresses to determine impact of interventions

Tabulate

Propose interventions for control of each stress

tools
machines
work station
materials
work methods
work standards
schedules

job analysis
Active and passive surveillance

Ergonomics training should be provided for:

Management so that they understand and support the program with adequate resources

All members of the ergonomic team to help them interpret health and job analysis data and make informed decisions regarding management of the program

Supervisors and workers so that they recognize and report stressful work situations and so that they can cooperate with intervention measures

Engineers so that they recognize stressful work designs and so that they can assist with design of interventions.

Training is an on-going process!

• Some time is generally required to identify and fix all work situations associated with cumulative trauma disorders.
• It is important that there be a program for restricted workers. This program should entail therapy, assessment of jobs and worker capac ity, worker placement and medical supervision. Management of restricted workers requires cooperation of the worker, the employer and the health care provider
• (Feuerstein et al, 1993; Oxenburgh et al 1985).
  
  

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  V. References