Ergonomics & people

Ergonomics is defined as the “study of human characteristics and the use of such knowledge to improve individuals’ interactions with the things they use and with the environments in which they use them” (Brooke and Reid, 1998, p. 459). In the United States, ergonomics is also known as “Human Factors” because of the emergence of many products that claimed to be “ergonomically design” and as such, it is usually described as “design for human beings” (Karwowski, 2006).

In relation to these, ergonomics also plays an important role in assuring that employees have a safe working environment especially when it comes to the machineries, tools, and other gadgets that are use in their respective profession. The vitality of ergonomics could be seen in the Health Hazard Evaluation (HHE) report about the United States Postal Service regarding their mail handling equipment.

The National Institute for Occupational Safety and Health (NIOSH) evaluated the potential ergonomics hazards that are related with the three types of automated mail processing machines that are use in the United States Postal Service namely: the Optical Character Reader (OCR), the Bar Code Sorter (BCS), and the Delivery Bar Code Sorter (DBCS). They also assessed the stool or “rest bar” that are used in the manual letter casing area. NIOSH perform the evaluation in order to determine whether the machineries use could be ergonomically hazardous, as it could develop work-related musculoskeletal disorders.

The ergonomic issues that were found involve the Pitney Bowes (P-B) OCR feeding table that was lower (31 inches) than the required work surface height (36-42 inches). The P-B stackers were deeper (25. 5 inches) than the required for work between the waist and shoulders (20 inches). Moreover, the vertical reaches that are needed to place the sorted mail from the stackers into trays were higher (between 47-64 inches) than the required heights (less than 50 inches).

Being the case, the NIOSH investigators identified that there are several ergonomic hazards that are related with the automated mail processing machines of the postal service like low back and upper extremity musculoskeletal disorders. They investigators also give emphasis on the design flaws regarding the DBCS sweeper position (Health Hazards Evaluation, 1993). The research was conducted by the NIOSH investigators by means of videotaping the employees through the use of ElectroCom Automation, Inc.

In August 1992, the investigators record the BCS and OCR machines that are use at the GMF in Merrifield, Virginia. Similarly, in December 1992, the NIOSH investigators also did the same thing at Denver GMF that are using the ECA, BCS, PB OCR, ECA, DBCS, and rest bar. Two ergonomist investigators reviewed the videotapes in order to assess whether there are ergonomic hazards in these mail-processing machines (Health Hazards Evaluation, 1993). The NIOSH investigators found out that manual letter sorting probably has little risk when it comes to musculoskeletal disorders.

On the other hand, working on automatic mail processing machines is potentially dangerous to employees because of the design flaws and the high volume conditions. Due to these, the NIOSH investigators recommend improving the machineries by reducing the trunk flexion while retrieving the trays of mail from the mail carriers. The OCR and BCS machines could also be safer to use by redesigning the workstation, which will reduce the degree of trunk flexion and arm reaching.

Furthermore, the manual operations that are involved with the mail processing machines should be automated especially when it comes to the sweeping positions. A good design given by the investigators is the “weight sensitive” stacker bin (Health Hazards Evaluation, 1993). This review made me realize that jobs that are very repetitive in nature like mail processing should be given due importance and attention especially when it comes to the machineries that they use.

Ergonomically unsafe machineries could bring serious damage to the employees of the postal system especially since they do the same process over and over again everyday (Helander, 2006). As such, it is indeed, beneficial that these reviews are made public in order to make the employers and employees aware of the potential risk in the workplace and to be able to properly address it. Lastly, the review should have also discuss more about the musculoskeletal disorders involve and what kind of ergonomic products could be use if there are employees who are suffering from such predicament.


Brooke, J. P. , and Reid, H. (1998). Rehabilitation of Movement. London: Saunders Company Ltd. Health Hazard Evaluation. (1993). United States Postal Service Denver General Mail Facility. Retrieved June 25, 2009, from http://www. cdc. gov/niosh/hhe/reports/pdfs/1992-0073-2337. pdf. Helander, M. (2006). A Guide to human factors and Ergonomics. NW: Taylor and Francis Group. Karwowski, W. (2006). Handbook on Standards and Guidelines in Ergonomics and Human Factors. New York: Routledge.