Physiological stresses in warehouse operations with special reference to lifting technique and gender: a case study

Area of Science:

• Occupational Health
• Ergonomics
• Workplace Safety

Background:

• Traditional lifting techniques, such as the straight-back, bent-knee method, are widely recommended in warehouses.
• The effectiveness and physiological impact of these techniques on workers performing routine tasks require further investigation.

Purpose of the Study:

• To compare the performance and physiological responses of male workers using free-style versus straight-back, bent-knee lifting techniques.
• To assess the physiological stress experienced by female order selectors using the free-style lifting technique.

Main Methods:

• A field study involving six male and six female grocery order selectors across three warehouses.
• Measurement of oxygen uptake and heart rates to assess physiological responses.
• Evaluation of worker performance using traditional work measurement techniques (time study, MTM, MSD).

Main Results:

• Male workers exhibited significantly lower performance levels and higher oxygen uptake and heart rates with the straight-back, bent-knee method compared to free-style lifting.
• Workers using the free-style technique lifted more cases, weight, and volume per minute.
• The straight-back, bent-knee method was found to be slower and more physiologically demanding.

Conclusions:

• The traditionally recommended straight-back, bent-knee lifting method is less efficient and more strenuous.
• Existing performance standards based on traditional work measurement techniques may be unattainable for workers using the straight-back, bent-knee method.
• Free-style lifting appears to be a more optimal technique for order selection tasks.