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Self-recordings of upper arm elevation during cleaning - comparison between analyses using a simplified reference

Camilla Dahlqvist1, Catarina Nordander2, Mikael Forsman3

  • 1Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE-221 85, Lund, Sweden. camilla.dahlqvist@med.lu.se.

BMC Musculoskeletal Disorders
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Summary

Employees can accurately self-record upper arm elevation using accelerometers and simplified instructions. This enables objective ergonomic risk assessment for preventing work-related musculoskeletal disorders.

Keywords:
Angular velocityArm elevationHotel housekeepingInclinometryPhysical workloadSelf-measurementZero position

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Area of Science:

  • Ergonomics and Occupational Health
  • Biomechanical Engineering
  • Workplace Safety Analysis

Background:

  • Ergonomic risk factors like awkward postures and high velocities necessitate objective risk assessments.
  • Technical methods for measuring physical workload are primarily used by researchers.
  • Self-recording of physical workload by employees is feasible with clear instructions and accelerometers.

Purpose of the Study:

  • To compare upper arm elevation analyses using a simplified vs. standard reference posture for self-recording.
  • To evaluate the comparability of self-recorded data with researcher-performed assessments.
  • To assess the difference between simplified and standard reference postures in ergonomic analysis.

Main Methods:

  • Twenty-eight cleaners used triaxial accelerometers to record upper arm elevation over 2-3 days.
  • Participants followed written instructions for a simplified reference posture and were later guided through a standard reference posture by a researcher.
  • Data analysis involved comparing recordings relative to both simplified and standard reference postures using Wilcoxon signed ranks test.

Main Results:

  • The group mean difference in upper arm elevation between simplified and standard reference analyses was minimal (0.2°).
  • The group mean difference between the simplified and standard reference postures themselves was 9°.
  • Participants successfully followed instructions, demonstrating feasibility of self-recording upper arm elevation and velocity.

Conclusions:

  • Self-recorded ergonomic data, when analyzed, is comparable to researcher-collected data on a group level.
  • Self-recording offers employers a viable method for objective risk assessment.
  • This approach provides a strong foundation for preventing work-related musculoskeletal disorders.