Bootstrap Exploration of the Duration of Surface Electromyography Sampling in Relation to the Precision of Exposure Estimation

Details

• Personal Author:
  Anton D ; Cavanaugh JE ; Cook TM ; Fethke NB ; Gerr F ; Anton D ; Cavanaugh JE ; Cook TM ; Fethke NB ; Gerr F
• Description:
  OBJECTIVES: This study examined the effect of sampling duration, in units of work cycles, on the precision of estimates of exposure to forceful exertion obtained with surface electromyography (EMG). METHODS: Recordings of the activity of the flexor digitorum superficialis, extensor digitorum, and upper trapezius muscles over 30 consecutive work cycles were obtained for a random sample of 25 manufacturing workers, each of whom was performing a unique production task representing a portion of the whole job. The mean root-mean-square amplitude and the 10th, 50th, and 90th percentiles of the distribution function of the amplitude probability were calculated for each cycle. Bootstrap analyses were used to examine the precision of the summary measures as the sampling duration increased incrementally from 1 to 30 work cycles. Precision was estimated by calculating the coefficient of variation (CV) of the bootstrap distributions at each sampling duration increment. RESULTS: The average minimum sampling duration for a bootstrap distribution CV of 15% ranged from 2.0 (SD 1.5) cycles to 7.5 (SD 9.6) cycles, depending on muscle and summary measure. For a 5% CV, the average minimum sampling duration ranged from 11.9 (SD 9.0) to 20.9 (SD 10.5) cycles. CONCLUSIONS: The results suggest that sampling as few as three work cycles was sufficient to obtain a bootstrap distribution CV of 15% for some of the muscles and summary measures examined in this study. While limited to machine-paced, cyclic manufacturing work, these results will assist the development of exposure assessment strategies in future epidemiologic studies of physical risk factors and musculoskeletal disorders. [Description provided by NIOSH]
• Subjects:
  Musculoskeletal Diseases Musculoskeletal System Occupational Health Safety
• Keywords:
  Analytical-processes Mathematical-models Musculoskeletal-system Musculoskeletal-system-disorders Repetitive-work Sampling Sampling-methods Statistical-analysis Worker-health
• ISSN:
  0355-3140
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article ; Journal Article
• Place as Subject:
  Iowa ; OSHA Region 10 ; OSHA Region 4 ; OSHA Region 7 ; Tennessee ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Pages in Document:
  358-367
• Volume:
  33
• Issue:
  5
• NIOSHTIC Number:
  nn:20033314
• Citation:
  Scand J Work Environ Health 2007 Oct; 33(5):358-367
• Contact Point Address:
  Dr N Fethke, East Tennessee State University, Environmental Health, Campus Box 70682, Johnson City, TN 37614, USA
• Email:
  nathan-fethke@etsu.edu
• Federal Fiscal Year:
  2008
• Performing Organization:
  University of Iowa - Iowa City
• Peer Reviewed:
  True
• Start Date:
  20030901
• Source Full Name:
  Scandinavian Journal of Work, Environment & Health
• End Date:
  20080831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:4b467f1b5d4f02e629254ecf38407180911122ab401d9ac75e2a9630830fd2e7520cb78eff60b9a99a5635e364760d104d9456a66b7aa6faa86fe95f5da59a16
• Download URL:
  https://stacks.cdc.gov/view/cdc/188942/cdc_188942_DS1.pdf
• File Type:
  [PDF - 231.54 KB ]