Affiliations: [a] Industrial Design, College of Design, North Carolina State University, Raleigh, NC, USA | [b] Ergonomics Division, Occupational & Environmental Safety, Duke University, Durham, NC, USA | [c] Bosco Perry Design, LLC, Potomac, MD, USA
Correspondence:
[*]
Corresponding author: Tamara James, Ergonomics Director, Duke University & Health System, Box 3834 DUMC, Durham, NC 27710, USA. Tel.: +1 919 681 3140; Fax: +1 919 286 6763; E-mail:tamara.james@duke.edu
Abstract:
BACKGROUND: Lighting is a part of every work task in the office environment,
yet it is often overlooked. Research links direct and indirect glare to
increased risk of visual discomfort among office workers with symptoms
ranging from dry eyes to blurry vision or headaches. Researchers have been
primarily concerned with those characteristics of task lighting that cause
glare including luminance level, position (line of sight), and control. It
is unknown what the benefits of adjustable task lights are and whether or
not their use has an effect on musculoskeletal comfort or posture. No
comprehensive field evaluations of this type were found among peer-reviewed,
indexed journals. OBJECTIVE: The purpose of this study was to assess the ergonomic and
calculated utility power consumption benefits of adjustable LED task
lighting in an office environment using a control/intervention experiment
design. METHODS: One hundred participants were originally recruited and randomly
assigned to intervention and control groups. Self-reported data was
collected on level of eye fatigue, perception of job content, intervention
usability, and musculoskeletal discomfort. Data was also collected on
workspace level of illumination and posture during standardized tasks
(assessed using RULA). RESULTS: Comparing baseline data to follow-up data for the intervention
group, the use of the adjustable, LED task lights provided statistically
significant, positive impacts on users' rating of discomfort, eye fatigue,
perception of job content, and posture between baseline and the short-term
follow up. CONCLUSIONS: Significant benefits to musculoskeletal comfort, posture, and
visual comfort were documented when participants used the adjustable task
lights. Participants' assessments of the light's usability, usefulness and
desirability were positive. There were no negative results found with
adjustable task light use.
