Elements of Ergonomics Programs A Primer Based on Workplace Evaluations of Musculoskeletal Disorders

Study	Industry	Study group	Intervention method	Summary of results	Additional comments
Itani et al. [1979]	Film manufacturing	124 film rollers in two groups	Reduced work time; increased number of rest breaks.	Reduced and shoulder disorders and low back complaints; improved worker health.	Productivity after the intervention was found to be 86% of the preintervention level.
Luopajarvi et al. [1982]	Food production	200 packers	Redesigned packing machine	Decreased neck, elbow, and wrist pain.	Not all recommended job changes were implemented; workers still complained.
Drury and Wick [1984]	Shoe manufacturing	Workers at 6 factory sites	Redesign workstation.	Reduced postural stress; increased productivity.	Trunk and upper limbs were most affected by changes.
Westgaard and Aaras [1984, 1985]	Cable forms production	100 workers	Introduced adjustable workstations and fixtures and counter-balanced tools.	Turnover decreased; musculoskeletal sick leave reduced by 67% over 8-year period; productivity increased.	Reductions in shoulder, upper back muscle load verified by EMG.
McKenzie et al. [1985]	Telecommunication equipment manufacturing	6,600 employees	Redesigned handles on power screwdrivers and wire wrapping guns and instituted plant-wide ergonomics program.	Incidence rate of repetitive trauma disorders decreased from 2.2 to .53 cases/200,000 work hours; lost days reduced from 1001 to 129 in 3 years.
Echard et al. [1987]	Automobile manufacturing	(Not indicated)	Redesigned tools, fixtures, and work organization in assembly operations.	Reduced long-term upper extremity and back disabilities; reduced carpal tunnel syndrome surgeries by 50%.
Lutz and Hansford [1987]	Medical products manufacturing	More than 1,000 workers	Introduced adjust-able workstations and fixtures and mechanical aids to reduce repetitive motions, and job rotation.	Medical visits reduced from 76 to 28 per month.	Employees also expressed enthusiasm for exercise program introduced with other interventions.
Jonsson [1988]	Telephone assembly, printed circuit card manufac-turing, glass blowing, mining	25 workers	Introduced job rotation.	Job rotation in light-duty tasks were not as effective as in dynamic heavy-duty tasks.	Measured static load on shoulder upper back muscles with EMG.
Geras et al. [1988]	Rubber and plastic parts manufacturing	87 plants within one company	Ergonomics training and intervention program introduced; added material handling equipment and workstation modifications to eliminate postural stresses.	Lost time prevalence rates at two plants reduced from 4.9 and 9.7/200,000 hours to 0.9 and 2.6, respectively, within 1 year and maintained over a 4-year period.	Success attributed to increased training, awareness of hazards, and improved communication between management and workers.
Tadano [1990]	Office	500 VDT operators	Provided training, redesigned workstations, and incorporated additional breaks and exercises into the work schedule.	Cumulative trauma disorder cases reduced from 49 in the 6 months preceding the intervention to 24 in the 6 months following the intervention.
Hopsu and Louhevaara [1991]	Office	8 female cleaners	Provided training and greater flexibility in the work and eliminated strictly proportioned work areas and time schedules.	Average sick leave decreased from 20 days/year before the intervention to 10 days/year 2 years after intervention.	Mean maximum VO2 rate increased, mean heart rate decreased after intervention.
LaBar [1992]	Household products manufac-turing	800 workers	Introduced adjustable workstations, improved the grips on handtools, improved parts organization, and work flow.	Reduced injuries (particularly back) by 50%.	Company also had a labor management safety committee to investigate ergonomics-related complaints.
Orgel et al. [1992]	Grocery store	23 employees	Redesigned checkout counter to reduce reach distances, installed a height-adjustable keyboard, and trained workers to adopt preferred work practices.	Decreased self-reported neck, upper back, and shoulder discomfort; no change in arm, forearm, and wrist discomfort.	The study lacked a reference group not subject to the same interventions for making suitable comparisons.
Rigdon [1992]	Bakery	630 employees	Formed union management committee to study cumulative trauma problems which led to workstation changes and tool modifications; improved work practices.	Cumulative trauma cases dropped from 34 to 13 in 4 years; lost days reduced from 731 to 8 during the same period.	Union advocated more equipment to reduce manual material handling.
Garg and Owen [1992]	Nursing home	57 nursing assistants	Implemented patient transferring devices.	IR of back injuries decreased from 83 to 43 per 200,000 work hours following the intervention; no lost or restricted work days during the 4 months following the intervention.
Halpern and Davis [1993]	Office	90 office workers	Adjusted workstations according to the workers' anthropometric dimensions.	Body part discomfort decreased; perceived efficiency and usability of the equipment increased.
Narayan and Rudolph [1993]	Medical device assembly plant	316 employees	Redesigned workstation to reduce reach distances, provided adjustable chairs and footrests, and provided fixtures and pneumatic gripper to eliminate pinch grips.	Plant-wide CTD incidence rate reduced from 13.7 to 11.3 per 200,000 worker hours after intervention, plant-wide severity rate reduced from 154.9 lost-time days to 67.8 lost time days per 200,000 worker hours	Not all jobs in plant affected by changes.
Parenmark et al. [1993]	Chain saw assembly plant	279 workers	Increased number of workers and tasks, provided training, reduced work pace, and adopted new wage system and flexible working hours.	Sick leave dropped from 17 to 13.7 days per worker per year; labor turnover dropped from 35% to 10%; assembly errors cut by 3%to 6%; total production cost reduced by 10%; productivity not affected.	Difficult to pinpoint which factor had biggest impact.
Shi [1993]	County government (various occupations represented)	205 workers	Introduced education, back safety training, and physical fitness activities and provided equipment and facility improvements (e.g., additional material handling equipment).	Back pain prevalence declined modestly; significant improvement in satisfaction, and a reduction in risky lifting behaviors were reported; a savings of $161,108 was realized, giving a 179% return in the investment.
Reynolds et al. [1994]	Apparel manufacturing	18 operators	Introduced height-and tilt-adjustable work stands, additional jigs, anti- fatigue mats, and automatic thread cutters.	Body part discomfort reduced in shoulders, arms, hands, and wrists; no injury costs incurred in 5 months following intervention.	Used worker participation approach; productivity significantly increased after intervention.
Aaras [1994]	Telephone exchange manufacturing, office	96 workers (divided into 4 groups)	Provided adjustable workstations and additional work space; tools were suspended and counterbalanced.	Significant reduction in intensity and duration of neck pain reported after intervention.	Reductions in static loading on the neck and shoulder muscles after intervention were confirmed via EMG.
Moore [1994]	Automotive engine and transmission manufac-turing	5 workers	Eliminated manual flywheel truing operation by implementing a mechanical press. 29% decrease in musculoskeletal disorders; 78% decrease in upper extremity CTDs; 82% reduction in restricted or lost work time.	Used participatory (team) approach to select intervention method.
NIOSH [1994]	Red meatpacking 3 beef and pork processing companies	Implemented a participatory (labor management) ergonomics program.	Results varied: only two teams able to introduce changes to address identified problems; some evidence that incidence and severity of injury was reduced following introduction of an ergonomics program.	Additional follow-up needed to evaluate intervention effectiveness.
NIOSH [1996]	Soft drink beverage delivery	9 driver-sales-workers	Installed pull-out steps, external handles and multi-shelving units to ease access to products, substituted plastic containers for glass to reduce weight, and redesigned carton for easier manual handling. In addition, 2-wheel hand trucks were modified to move easier over rough terrain. Reductions in biomechanical stressors for the back and shoulders were observed when removing products from truck; heart rate decreased for 6 of 9 drivers despite increase in product volume. Reports of worker fatigue dropped; reductions in multiple handling of beverage cases and decreased awkward posture were also observed.

THIS PAGE WAS LAST UPDATED ON SEPTEMBER 15, 1997