Ergonomic design and evaluation of a clinical laboratory for people with disabilities of the lower limbs

Wei-Chun Chen, Purdue University

Abstract

Objective: The purpose of this study was to use ergonomic principles to design and evaluate a clinical laboratory environment so that people with disabilities of the lower limbs could work and thrive in such environments. Methods: There were two parts. Part I was to use ergonomic principles with ADA (Americans with Disabilities Act) standards to redesign a clinical laboratory in the Discover Learning and Research Center (DLRC) for subjects with lower limb disabilities. Part II was to evaluate the suitability and functionality of the redesigned clinical laboratory in the DLRC for workers with lower limb disabilities. There were a total of 19 subjects: 8 subjects worked in a veterinary clinical pathology (VCP) laboratory in the school of veterinary medicine of Purdue's West Lafayette, Indiana campus. The other 11 subjects performed simulated clinical laboratory functions in the DLRC redesigned laboratory. Three of the 11 subjects had true lower limb disabilities, while the remainder were able bodied but performed the laboratory tasks in a standard wheelchair. Based on the primary tasks of pipetting, microscope use and slide smear preparation in the clinical laboratory, the DLRC subjects performed these same tasks, specifically: pipetting (using old and new pipettes), microscope use, and slide smear preparation. All 11 subjects in the DLRC and representative subjects in the veterinary clinical pathology (VCP) laboratory on Purdue's West Lafayette, Indiana campus had videos and pictures taken of their work. The Rapid Upper Limb Assessment (RULA), a standardized numeric ergonomics assessment tool) was used on the 11 subjects to determine if pipetting (old and new methods), microscope use and slide smear preparation could pose work-related musculoskeletal disorders. The higher the RULA score the greater the potential risk for musculoskeletal injury and/or illness. Independent T-Tests were used to evaluate the significant differences between two laboratories (VCP laboratory and DLRC laboratory) on demographic data and between two groups (subjects with true lower limb disabilities and subjects without physical disabilities who performed tasks in a wheelchair) in the DLRC laboratory on the mean RULA scores. Furthermore, one-way ANOVA was used to compare the significant differences of RULA scores between four tasks in the DLRC laboratory. All 19 subjects filled out the Nordic Musculoskeletal Questionnaire. Results: Part I. There were several changes to the original laboratory design including: a modified ventilated hood that was lowered to accommodate workers in wheelchairs; cabinet doors below the ventilated hood and sink that were removed to allow wheelchair access, additional light and power switches were installed for easy function and reach while in the seated position, a shallow sink replaced the deep sink and ADA-compliant water faucets replaced the existing standard water faucets. An adjustable height work table was installed to raise and lower the microscope so that it was comfortable for the subject while performing this task in a wheelchair. Part II. Seventy five percent of the VCP laboratory subjects in the veterinary clinical pathology laboratory reported discomfort of the neck and eyes after performing their laboratory tasks. Personal interviews, observation and basic work analyses, photos, and video vignettes of the veterinary clinical laboratory subjects showed that the primary tasks they performed during work was: pipetting tasks (56%), microscope tasks (28%), and slide smear preparation tasks (17%). When evaluating the subjects in the DLRC laboratory, there were no significant differences between the 8 able bodied subjects performing the pipetting, microscope and slide smear preparation tasks compared to the 3 subjects who had permanent lower limb disabilities performing the same laboratory tasks. Based on RULA scores, the old pipetting task proved to be the most challenging of all the tasks performed by the DLRC subjects. When the laboratory tasks were compared with each other: (i.e., 1. old pipetting; 2. new pipetting; 3. microscope use; and 4. slide smear preparation), the RULA scores showed that old pipetting tasks were higher than microscope tasks, which microscope tasks were higher than new pipetting tasks, and new pipetting tasks were higher than slide smear preparation tasks. However, the old pipetting tasks were not significantly different than microscope tasks, but were significantly different from the new pipetting tasks and slide smear preparation tasks (p < .05). According to the one-way ANOVA tests, there was a significant difference of the mean RULA scores among the laboratory tasks ( F(3,40)=4.518, p<0.05). Similarly, there was also a significant difference based on the mean RULA scores of upper extremity among the laboratory tasks ( F(3,40)=12.186, p<0.001). (Abstract shortened by UMI.)

Degree

M.S.

Advisors

McGlothlin, Purdue University.

Subject Area

Occupational safety|Health sciences

COinS