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A Comparison of Accelerometer Accuracy in Older Adults
Research in Gerontological Nursing
|May 6, 2015
Summary
Activity monitors struggle to accurately count steps in older adults with gait disorders. Ankle-mounted devices showed better agreement, but gait speed significantly impacts accelerometer accuracy.
Area of Science:
- Gerontology
- Biomedical Engineering
- Physical Therapy
Background:
- Gait disorders are common in older adults, complicating accurate activity monitoring.
- Existing activity monitors may not reliably capture step counts in this population.
- Accurate activity monitoring is crucial for assessing health and mobility in elderly individuals.
Purpose of the Study:
- To compare the accuracy of accelerometer-based step counts against direct observation in older adults.
- To evaluate the influence of accelerometer placement and gait speed on activity monitor accuracy.
- To determine gait speed thresholds for acceptable accelerometer accuracy.
Main Methods:
- Fifty residents from residential care/assisted living facilities participated.
- Participants wore Fitbit® Tracker and waist-, wrist-, and ankle-mounted Actigraph GT1M devices.
- Step counts were compared to hand-tallied steps using CCC, ratios, differences, and Bland-Altman plots.
Main Results:
- All tested accelerometers underestimated true step counts.
- Only the ankle-mounted Actigraph GT1M showed positive agreement (CCC = 0.205).
- Required gait speeds for ≥0.80 accuracy were ≥0.56 m/s (Fitbit) and ≥0.71 m/s (ankle GT1M).
Conclusions:
- Accelerometer accuracy for step counting in older adults is influenced by device placement and individual gait speed.
- Ankle-mounted accelerometers demonstrate potential for improved accuracy in this demographic.
- Further research is needed to optimize activity monitoring for older adults with gait impairments.
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