NIOSH Elements of Ergonomics Programs

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

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Tray 7–A. Select Studies Demonstrating Effectiveness of Engineering Controls for Reducing Exposure to Ergonomic Risk Factors

Tray 7–A. Select Studies Demonstrating Effectiveness of Engineering Controls for Reducing Exposure to Ergonomic Risk Factors

Study Target population Problem and risk factor Control measure Effect

Miller et al. [1971] Surgeons (use of bayonet forceps) Muscle fatigue during forceps use, frequent errors in passing instruments Redesigned forceps (increased surface area of handle). Reduced muscle tension (determined by EMG) and number of passing errors.

Armstrong et al. [1982] Poultry cutters (knives) Excessive muscle force during poultry cutting tasks Redesigned knife (reoriented blade, enlarged handle, provided strap for hand). Reduced grip force during use, forearm muscle fatigue.

Knowlton and Gilbert [1983] Carpenters (hammers) Muscle fatigue, wrist deviation during hammering Bent handle of hammer and its diameter. Produced smaller decrement in strength and reduced ulnar wrist deviation.

Habes [1984] Auto workers Back fatigue during embossing tasks Designed cut-out in die to reduce reach distance. Reduced back muscle fatigue as determined by EMG.

Goel and Rim [1987] Miners (pneumatic chippers) Hand-arm vibration Provided padded gloves. Reduced vibration by 23.5% to 45.5%.

Wick [1987] Machine operators in a sandal plant Pinch grips, wrist deviation, high repetition rates, static loading of legs and back Provided adjustable chairs and bench-mounted armrests; angled press; furnished parts bins. Reduced wrist deviation and compressive force on lumbar-sacral discs from 85 to 13 lb.

Little [1987] Film notchers Wrist deviation, high repetition rates, pressure in the palm of the hand imposed by notching tool Redesigned notching tool (extended, widened and bent handles, reduced squeezing force). Reduced squeezing force from 15 to 10 lb; eliminated wrist deviation; increased productivity by 15%.

Johnson [1988] Power handtool users Muscle fatigue, excessive grip force Added vinyl sleeve and brace to handle. Reduced grip force as determined by EMG.

Fellows and Freivalds [1989] Gardeners (rakes) Blisters, muscle fatigue Provided foam cover for handle. Reduced muscle tension and fatigue buildup as determined by EMG.

Andersson [1990] Power handtool users Hand-arm vibration Provided vibration damping handle. Reduced hand-transmitted vibration by 61% to 85%.

Radwin and Oh [1991] Trigger-operated power hand tool users Excessive hand exertion and muscle fatigue Extended trigger. Reduced finger and palmar force during tool operation by 7%.

Freudenthal et al. [1991] Office workers Static loading of back and shoulders during seated tasks Provided desk with 10 degree incline and adjustable chair; provided adjustable tables. Reduced moment of force on lower spinal column by 29% and by 21% on upper part.

Powers et al. [1992] Office workers Wrist deviation during typing tasks Provided forearm supports and a negative slope keyboard support system. Reduced wrist extension.

Erisman and Wick [1992] Assembly workers Pinch grips, wrist deviation Provided new assembly fixtures. Eliminated pinch grips; reduced wrist deviations by 65%; reduced cycle time by 50%.

Luttmann and Jager [1992] Weavers Forearm muscle fatigue Redesigned workstation (numerous changes). Reduced fatigue as measured by EMG and improved quality of product.

Fogleman et al. [1993] Poultry workers (knives) Excessive hand force, wrist deviation Altered blade angle and handle diameter. Wrist deviation reduced with altered blade angle.

Lindberg et al. [1993] Seaming operators Awkward, fixed (static) neck and shoulder postures, monotonous work movements, high work pace Automated seaming task Provide freer head postures during automated seaming; reduced loads on neck and shoulder muscles as indicated by EMG; reduced perceived exertion.

Nevala-Puranen et al. [1993] Dairy farmers Whole-body fatigue, bent and twisted back postures, static arm postures Installed rail system for carrying milking equipment. Heart rate decreased; bent and twisted back and trunk postures decreased by 64%; above-shoulder arm postures cut in half; mean milking time per cow decreased by 24%.

Degani et al. [1993] Construction workers, landscapers (shovels) Whole-body and local muscle fatigue Modified shovel handle (mounted second shaft on handle). EMG in the lower back muscles reduced; exertion showed less effort.

Gallimore and Brown [1993] VDT operators Visual fatigue and body discomfort due to operators adopting static postures Fitted VDT screens with a device to move the image further away from the eye. Glare reduced and awkward neck postures reduced for bifocal wearers.

Wick and Deweese [1993] Shipping clerks Wrist deviations; high pinch grip forces; awkward shoulder, neck, and back postures Lowered and tilted the workstation; raised storage racks; provided a cutting device for wrapping materials. Workstation changes reduced awkward wrist, shoulder, back, and neck postures; cutting tool reduced pinch grip problem; cycle time reduced by 12%.

Peng [1994] Assemblers (percussive rivet tools) Vibrations Modified rivet hammer in numerous ways; introduced "recoilless" bucking bar. Vibration at the bucking bar and rivet hammer handle reduced.

Back to Tray 7 || Table of Contents || Tray 7-A & 7-B References || To Tray 7-B

Study	Target population	Problem and risk factor	Control measure	Effect
Miller et al. [1971]	Surgeons (use of bayonet forceps)	Muscle fatigue during forceps use, frequent errors in passing instruments	Redesigned forceps (increased surface area of handle).	Reduced muscle tension (determined by EMG) and number of passing errors.
Armstrong et al. [1982]	Poultry cutters (knives)	Excessive muscle force during poultry cutting tasks	Redesigned knife (reoriented blade, enlarged handle, provided strap for hand).	Reduced grip force during use, forearm muscle fatigue.
Knowlton and Gilbert [1983]	Carpenters (hammers)	Muscle fatigue, wrist deviation during hammering	Bent handle of hammer and its diameter.	Produced smaller decrement in strength and reduced ulnar wrist deviation.
Habes [1984]	Auto workers	Back fatigue during embossing tasks	Designed cut-out in die to reduce reach distance.	Reduced back muscle fatigue as determined by EMG.
Goel and Rim [1987]	Miners	(pneumatic chippers) Hand-arm vibration	Provided padded gloves.	Reduced vibration by 23.5% to 45.5%.
Wick [1987]	Machine operators in a sandal plant	Pinch grips, wrist deviation, high repetition rates, static loading of legs and back	Provided adjustable chairs and bench-mounted armrests; angled press; furnished parts bins.	Reduced wrist deviation and compressive force on lumbar-sacral discs from 85 to 13 lb.
Little [1987]	Film notchers	Wrist deviation, high repetition rates, pressure in the palm of the hand imposed by notching tool	Redesigned notching tool (extended, widened and bent handles, reduced squeezing force).	Reduced squeezing force from 15 to 10 lb; eliminated wrist deviation; increased productivity by 15%.
Johnson [1988]	Power handtool users	Muscle fatigue, excessive grip force	Added vinyl sleeve and brace to handle.	Reduced grip force as determined by EMG.
Fellows and Freivalds [1989]	Gardeners (rakes)	Blisters, muscle fatigue	Provided foam cover for handle.	Reduced muscle tension and fatigue buildup as determined by EMG.
Andersson [1990]	Power handtool users	Hand-arm vibration	Provided vibration damping handle.	Reduced hand-transmitted vibration by 61% to 85%.
Radwin and Oh [1991]	Trigger-operated power hand tool users	Excessive hand exertion and muscle fatigue	Extended trigger.	Reduced finger and palmar force during tool operation by 7%.
Freudenthal et al. [1991]	Office workers	Static loading of back and shoulders during seated tasks	Provided desk with 10 degree incline and adjustable chair; provided adjustable tables.	Reduced moment of force on lower spinal column by 29% and by 21% on upper part.
Powers et al. [1992]	Office workers	Wrist deviation during typing tasks	Provided forearm supports and a negative slope keyboard support system.	Reduced wrist extension.
Erisman and Wick [1992]	Assembly workers	Pinch grips, wrist deviation	Provided new assembly fixtures.	Eliminated pinch grips; reduced wrist deviations by 65%; reduced cycle time by 50%.
Luttmann and Jager [1992]	Weavers	Forearm muscle fatigue	Redesigned workstation (numerous changes).	Reduced fatigue as measured by EMG and improved quality of product.
Fogleman et al. [1993]	Poultry workers (knives)	Excessive hand force, wrist deviation	Altered blade angle and handle diameter.	Wrist deviation reduced with altered blade angle.
Lindberg et al. [1993]	Seaming operators	Awkward, fixed (static) neck and shoulder postures, monotonous work movements, high work pace	Automated seaming task	Provide freer head postures during automated seaming; reduced loads on neck and shoulder muscles as indicated by EMG; reduced perceived exertion.
Nevala-Puranen et al. [1993]	Dairy farmers	Whole-body fatigue, bent and twisted back postures, static arm postures	Installed rail system for carrying milking equipment.	Heart rate decreased; bent and twisted back and trunk postures decreased by 64%; above-shoulder arm postures cut in half; mean milking time per cow decreased by 24%.
Degani et al. [1993]	Construction workers, landscapers (shovels)	Whole-body and local muscle fatigue	Modified shovel handle (mounted second shaft on handle).	EMG in the lower back muscles reduced; exertion showed less effort.
Gallimore and Brown [1993]	VDT operators	Visual fatigue and body discomfort due to operators adopting static postures	Fitted VDT screens with a device to move the image further away from the eye.	Glare reduced and awkward neck postures reduced for bifocal wearers.
Wick and Deweese [1993]	Shipping clerks	Wrist deviations; high pinch grip forces; awkward shoulder, neck, and back postures	Lowered and tilted the workstation; raised storage racks; provided a cutting device for wrapping materials.	Workstation changes reduced awkward wrist, shoulder, back, and neck postures; cutting tool reduced pinch grip problem; cycle time reduced by 12%.
Peng [1994]	Assemblers (percussive rivet tools)	Vibrations	Modified rivet hammer in numerous ways; introduced "recoilless" bucking bar.	Vibration at the bucking bar and rivet hammer handle reduced.

THIS PAGE WAS LAST UPDATED ON SEPTEMBER 15, 1997