Prediction of Trapezius Muscle Activity and Shoulder, Head, Neck, and Torso Postures During Computer Use: Results of a Field Study

Details

• Personal Author:
  Bruno Garza JL ; Catalano PJ ; Dennerlein, Jack T. ; Eijckelhof BHW ; Huysmans MA ; Johnson PW ; Katz JN ; van der Beek AJ ; van Dieen JH
• Description:
  Background: Due to difficulties in performing direct measurements as an exposure assessment technique, evidence supporting an association between physical exposures such as neck and shoulder muscle activities and postures and musculoskeletal disorders during computer use is limited. Alternative exposure assessment techniques are needed. Methods: We predicted the median and range of amplitude (90th-10th percentiles) of trapezius muscle activity and the median and range of motion (90th-10th percentiles) of shoulder, head, neck, and torso postures based on two sets of parameters: the distribution of keyboard/mouse/idle activities only ("task-based" predictions), and a comprehensive set of task, questionnaire, workstation, and anthropometric parameters ("expanded model" predictions). We compared the task-based and expanded model predictions based on R2 values, root mean squared (RMS) errors, and relative RMS errors calculated compared to direct measurements. Results: The expanded model predictions of the median and range of amplitude of trapezius muscle activity had consistently better R2 values (range 0.40-0.55 compared to 0.00-0.06), RMS errors (range 2-3%MVC compared to 3-4%MVC), and relative RMS errors (range 10-14%MVC compared to 16-19%MVC) than the task-based predictions. The expanded model predictions of the median and range of amplitude of postures also had consistently better R2 values (range 0.22-0.58 compared to 0.00-0.35), RMS errors (range 2-14 degrees compared to 3-22 degrees), and relative RMS errors (range 9-21 degrees compared to 13-42 degrees) than the task-based predictions. Conclusions: The variation in physical exposures across users performing the same task is large, especially in comparison to the variation across tasks. Thus, expanded model predictions of physical exposures during computer use should be used rather than task-based predictions to improve exposure assessment for future epidemiological studies. Clinically, this finding also indicates that computer users will have differences in their physical exposures even when performing the same tasks. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Computers Ergonomics Musculoskeletal Diseases Musculoskeletal System Occupational Health Safety
• Keywords:
  Anthropometric Parameter Author Keywords: Root Mean Square Error Biomechanics Exposure Assessment Maximum Voluntary Contraction MSD Muscle Activity Musculoskeletal Disorders Posture Root Mean Square
• ISSN:
  1471-2474
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Connecticut ; Massachusetts ; OSHA Region 1 ; OSHA Region 10 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  15
• NIOSHTIC Number:
  nn:20054795
• Citation:
  BMC Musculoskelet Disord 2014 Sep; 15:292
• Contact Point Address:
  Jack T Dennerlein, Department of Environmental Health, Harvard University, Boston, USA
• Email:
  j.dennerlein@neu.edu
• Federal Fiscal Year:
  2014
• NORA Priority Area:
  Healthcare and Social Assistance ; Services
• Performing Organization:
  Harvard University, School of Public Health, Boston, Massachusetts
• Peer Reviewed:
  True
• Start Date:
  20080901
• Source Full Name:
  BMC Musculoskeletal Disorders
• End Date:
  20130831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:1bb18963427fc727446fc5ab3ba0ab6cf15d4a61aee9bf76e207bd8317831a50c153af3e365b09ac9bdccf0920c6c8d5c4daa868c0f5b1b9f511bf9e3c6dd8ed
• Download URL:
  https://stacks.cdc.gov/view/cdc/217226/cdc_217226_DS1.pdf
• File Type:
  [PDF - 378.20 KB ]