Effect of concrete block weight and wall height on electromyographic activity and heart rate of masons

Abstract

Work-related musculoskeletal disorders (MSDs) are common among construction workers, such as masons. Few interventions are available to reduce masons' exposure to heavy lifting, a risk factor for MSDs. The purpose of this study was to determine whether one such intervention, the use of light-weight concrete blocks (LWBs), reduces physiological loads compared to standard-weight blocks (SWBs).

Using a repeated measures design, 21 masons each constructed two 32-block walls, seven courses (rows) high, entirely of either SWBs or LWBs. Surface electromyography (EMG), from arm and back muscles, and heart rate was sampled.

For certain muscles, EMG amplitudes were slightly lower when masons were laying LWBs compared to SWBs. Upper back and forearm extensor EMG amplitudes were greater for the higher wall courses for both block weights. There were no significant differences in heart rate between the two blocks. Interventions that address block weight and course height may be effective for masons.

Keywords:

• Musculoskeletal disorders
• Construction
• Intervention effectiveness
• Masonry
• Electromyography

Acknowledgements

This study was supported by the Center to Protect Workers' Rights using funding from the National Institute for Occupational Safety and Health, grant number CCU317202. The contents are solely the responsibility of the authors. The authors would like to thank the masons who participated from the International Union of Bricklayers & Allied Craftworkers Local No. 3 of Iowa. Additional thanks to Mr. Russ Gunderson, Mr. Craig Gunderson, Mr. Gary Pribyl, and Mr. Tim Wright for technical assistance, and Dr. Bridget Zimmerman for her statistical guidance.