Skin Temperature in the Hands of Office Workers

Details

• Personal Author:
  Gold JE
• Description:
  Musculoskeletal disorders, including those localized to the upper extremity such as carpal tunnel syndrome (CTS) and forearm tendinitis, comprised 30 percent of the approximately 1.2 million total workplace illnesses and injuries reported in 2006 in the United States according to the Bureau of Labor Statistics. While UEMSDs occur in many types of exposed jobs, a major source of concern is computer keyboard work where associations between UEMSDs and keyboard usage have been reported in epidemiological studies. The U.S. Census Bureau has estimated that half of employed adults used a computer on the job in 1997. In 2003, 73.5% of those in office and administrative support positions reported using a computer at work. Although highly prevalent, objective options for surveillance, screening and diagnosis of upper extremity musculoskeletal disorders (UEMSDs) are few. Additionally, with the exception of CTS, pathophysiology in UEMSDs is little understood. Several investigators have theorized a role for blood flow abnormalities. Subcutaneous perfusion is a major determinant of skin temperature, which in turn, is detectable through infrared thermography (far-infrared imaging). The overall aim of the study was to determine the utility of infrared thermography for evaluation of UEMSDs and for improved understanding of UEMSD pathophysiology. The dorsal mean temperature in the hands of office workers (n = 45) was measured before and after a 9-minute typing task under controlled ambient temperature conditions. Ten asymptomatic controls and 35 subjects with symptoms in the right distal arm (elbow, wrist, or hand) were imaged for one minute prior to typing and at three 2-minute imaging periods during the 10 minutes following the typing task. Also, a near infrared spectroscopy (NIRS) probe measured relative blood volume (RBV) in the first dorsal interosseous muscle (FDI) during the experiment. The objective of Aim 1 was to evaluate the reproducibility and reliability of dorsum mean temperature thermography (DMTT). Mean temperature of the dorsal hand as ascertained through infrared thermography proved to be reliable before and after a 9-minute typing task under controlled ambient temperature conditions. Good to excellent reproducibility was obtained for controls at room temperature (22 degrees C). The objective of Aim 2 was to use DMTT to investigate differences between symptomatic and asymptomatic office workers. Mean temperature in the dorsal hand was associated with severity of musculoskeletal disorders in office workers. Specifically, as compared with asymptomatic controls, we measured colder pre-typing hand temperatures in cases a) with more anatomically widespread symptoms, and b) meeting more case definitions of upper extremity musculoskeletal disorders as ascertained through a physical examination and symptom reports. The objective of Aim 3 was to estimate the correlation between skin temperature (DMTT) and subcutaneous blood volume as measured by near-infrared spectroscopy. Post-typing mean dorsal hand temperature and muscle blood volume in the FDI as determined through NIRS were moderately correlated during a 10 minute recovery period post-typing. Hence, skin temperature in response to a typing challenge does appear to reflect underlying muscle perfusion in the hand. The reliability of thermography under controlled ambient temperature and the decreased mean dorsal hand temperature found in those with more severe UEMSDs bodes well for the consideration of the method for screening or surveillance in the workplace and diagnosis in the clinic. We found that a short typing task (possibly generalizable to other low-level manual activity) in asymptomatic subjects resulted in reduced skin temperature to the hands and likely reduced perfusion to the underlying muscles under ambient temperature conditions (18 degrees C) frequently encountered in cooler workplaces (such as in an office during the summer with air conditioning or in industrial environments during the winter). Ambient temperature should be measured in epidemiological studies of manual workers to further explore the association of this risk factor with UEMSDs. As a precautionary measure, workplaces warmer than 18 degrees C are suggested. Altered blood flow and sympathetic nervous system dysfunction are likely involved in the pathophysiology of UEMSDs. Further research, including longitudinal studies, is recommended to further elucidate this relationship. [Description provided by NIOSH]
• Subjects:
  Mining Occupational Health Safety
• Keywords:
  Arm Injuries Carpal Tunnel Syndrome Circulatory System Cold Environments CTS Hand Injuries Infrared Spectroscopy Keyboard Operators MSD Musculoskeletal Disorders Office Workers Physiological Measurements Skin Tests Temperature Effects Temperature Measurement Thermal Effects Upper Extremities

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• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-21
• NIOSHTIC Number:
  nn:20053124
• NTIS Accession Number:
  PB2019-100123
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, K01-OH-008134, 2009 Apr; :1-21
• Contact Point Address:
  Judith E. Gold, Assistant Professor, Department of Public Health, Temple University, 1301 Cecil B. Moore Ave., 9th fl. 004-09, Philadelphia, PA 19122
• Email:
  jgold@temple.edu
• Federal Fiscal Year:
  2009
• Performing Organization:
  Temple University, Philadelphia, Pennsylvania
• Peer Reviewed:
  False
• Start Date:
  20050901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20090228
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f10b681d7226c5df9beb4666dda974047d2f1c5c30aed5bae0ae60956730ccbfcc4e5bff0209400fd2e6f8805450f935b48fb9d221b775ddb44ac76abebc0489
• Download URL:
  https://stacks.cdc.gov/view/cdc/218748/cdc_218748_DS1.pdf
• File Type:
  [PDF - 9.33 MB ]