Using the RT3 accelerometer to measure everyday activity in functionally impaired older people

Area of Science:

• Gerontology
• Biomedical Engineering
• Physical Activity Measurement

Background:

• Triaxial accelerometry offers a simple method for assessing physical activity in older adults.
• The influence of walking aids and accelerometer placement on these measurements is not well understood.

Purpose of the Study:

• To investigate the impact of accelerometer placement, walking aid use, and activity type on RT3 triaxial accelerometer data in older individuals.
• To determine optimal accelerometer usage for accurate physical activity monitoring in this demographic.

Main Methods:

• Twenty older adults (over 65) and five younger volunteers participated.
• Subjects performed standardized activities (standing, sitting, rest, walking, stair climbing) with RT3 accelerometers placed on both hips.
• Data was collected while participants used various walking aids.

Main Results:

• Significant differences in accelerometer counts were observed between left and right hip placements, with high correlation for walking and stair climbing but not sedentary tasks.
• Walking activity generated counts between 250-3000 min-1 and was proportional to distance.
• Sedentary activities produced counts below 250 min-1, lacking clear differentiation.
• Walking aids did not influence accelerometer counts.

Conclusions:

• Walking can be differentiated from other activities using specific count thresholds.
• For consistent RT3 accelerometer measurements in older adults, placement on the same body side is advised.
• The use of walking aids does not appear to alter RT3 accelerometer readings.