Ergonomic analysis of workstation design for Galaxie Library Bookdrop, Apple Valley, MN

Abstract

The purpose of this study was to identify whether ergonomically related risk factors are present in the current workstation design of Galaxie Library's drive-thru bookdrop in Apple Valley, MN and compare probability of injury to proposed redesigned workstations. Redesign of the workstation to fit the workers and redesigning jobs to reduce or eliminate the amount of manual material handling has been recommended by various professionals, in the ergonomics field, to reduce job-related back pain. While none of the Galaxie Library employees has filed worker compensation claims for these ailments, human loss is occurring through their pain and suffering. Stover Snook points out that "…approximately 80 percent of the population experience low back pain sometime during life, yet treatment of these symptoms have not been very successful" (1987, p. 52). Back problems are the single most costly workplace injury and represent 32 percent of all workers' compensation claims (Johnson, Baldwin, and Butler, 1998). Good work station design, mechanical aids, proper seating and appropriate object weights have reduced industrial low back pain by up to one-third (Snook, 1987). Job design analysis identifies individual tasks a worker is required to perform and then identifies the ergonomic risk factors associated with job task(s) (Armstrong, Radwin, Hansen, and Kennedy, 1986). If risk factors are identified, the observations, possibly combined with video observation, can lead to biomechanical monitoring and investigation to determines how the joint of interest is loaded during dynamic motion (Marras, 1992). The Risk Management Department for Dakota County decided to conduct a job analysis of assigned job tasks at Galaxie Library. Video-observation of the book return process was utilized to correctly ascertain the book collection process. To evaluate and monitor the information assistant’s lumbar position, while gathering materials, a Lumbar Motion was utilized to evaluate the current workstation to the proposed workstation design. For comparing the proposed workstation design to the present workstation design, there was a 69% decrease in sagittal motion and 60% decrease in the velocity of the movement. There was also a 69% decrease in acceleration / deceleration rate. As a result of this analysis process, it was determined that employees associated with the book collection/sorting process were at moderate risk of back injury. Study results combined with a literature review indicated that workstation redesign, an evaluated conveyor type system with spring loaded carts (or other non-manually bottom lifting cart), would decrease the amount of lumbar motion and potential of injury significantly This study was conducted Spring of 1999.