Assessment of Physical Work Demands of Home Care Workers in Norway: An Observational Study Using Wearable Sensor Technology

Abstract

Objectives: High physical work demands are believed to be partly responsible for the high sickness absence among home care workers, but no studies have assessed their physical work demands using precise device-based measurements. Hence, the objective of this observational study was to assess physical work demands in home care, using wearable sensors.

Methods: From six home care units in a large municipality in Norway, 114 of 195 eligible home care workers filled in a questionnaire, a diary about work hours, and wore five accelerometers, and a heart rate sensor for up to six consecutive workdays.

Results: On average, the homecare workers spent 50% of the working hours sitting, 25.2% standing, 11.4% moving, 8.3% walking fast, 1.9% walking slow, 1.2% stair-climbing, 0.3% cycling, and 0.05% running. We found the following exposures to demanding postures: arm-elevation in an upright body position ≥30° was 36.7%, ≥60° was 4.1%, and ≥90°was 0.5%; forward trunk inclination in an upright body position ≥30° was 9.9%, ≥60° was 4%, and ≥90° was 1%; and for kneeling it was 0.8%. We found the average cardiovascular load (%heart rate reserve) during work to be 28%. There was considerable individual variation in these physical exposures at work.

Conclusions: This study presents precise information on various physical work demands of home care workers in Norway. Home care workers spent on average half the workday sitting and the remaining time in various occupational physical activities. Presently, few device-based exposure limits have been proposed for acceptable amounts of occupational physical exposures, but the level of arm-elevation, forward trunk inclination, and the considerable variation of physical workloads among home care workers, indicate that preventive measures should be taken.

Keywords: accelerometry; ergonomics; heart rate monitor; human factors; manual labor; occupational health and safety; occupational physical activity; physical exposures.

Figure 1.

Flow of participants.

Figure 2.

Time in minutes spent in occupational physical activity (A) and the corresponding %HRR (B). The violin plots depict information about the distribution of the data. The box displays the median, 25th and 75th percentile and the black lines are showing the rest of the distribution.

Figure 3.

Occupational physical activity on an individual level. Home care workers are represented during working hours on the x-axis and on the y-axis (A) Minutes in LIPA (light intensity physical activity: standing, moving, and walking slow) and MVPA (moderate to vigorous physical activity: walking fast, running, stairclimbing, and cycling) and total activity (LIPA+MVPA); (B) total steps for each home care worker; (C) total minutes sitting during working hours; and (D) mean %HRR for each home care worker and time in percentage spent with at least 33% HRR. The black horizontal dotted lines in A–C depicts the threshold for 50% of workday and in D the threshold for 33% HRR.

Figure 4.

Demanding postures on an individual level. Home care workers are represented during working hours on the x-axis and on the y-axis (A) total minutes arm-elevation ≥30°, ≥60°, and ≥90° in an upright body position, (B) total minutes ≥30°, ≥60°, and ≥90° forward trunk inclination in an upright body position and (C) total minutes kneeling.