Wrist activity monitor counts are correlated with dynamic but not static assessments of arm elevation exposure made with a triaxial accelerometer

Abstract

There is evidence in the literature of a link between workplace arm elevation exposure and atraumatic shoulder injuries. However, there are several methods that can be used to assess this exposure. The goal of the present study was to compare the outcomes of an activity monitor attached to the wrist and a triaxial accelerometer mounted on the humerus. Twenty-one workers wore both sensors over the course of a full workday. While the activity monitor data was not significantly correlated with any static humeral parameters, it was strongly correlated with all dynamic parameters. The use of a simple, commercially available activity monitor might offer an inexpensive alternative for the assessment of a large number of subjects over multiple workdays to determine the relationship between dynamic motion and occupation shoulder injuries in the future.

Practitioner Summary: Arm overuse has been linked to occupation-related shoulder injuries. An activity monitor attached to the wrist and a triaxial accelerometer mounted on the humerus were compared in a field trial. The results demonstrate that, under certain conditions, a commercially available activity monitor might be a useful tool for exposure assessment.

Keywords:

• shoulder
• exposure
• accelerometers
• overuse injuries

Acknowledgements

This research was partially supported by NIOSH grant # 5R01OH008288. Additionally, the authors would like to thank the anonymous reviewer who suggested the use of the dynamic acceleration parameter.