TY  - JOUR
PY  - 2014//
TI  - Can we use accelerometry to monitor balance exercise performance in older adults?
JO  - Gait and posture
A1  - Tung, James Y.
A1  - Ng, Helen
A1  - Moore, Cameron
A1  - Giangregorio, Lora M.
SP  - 991
EP  - 994
VL  - 39
IS  - 3
N2  - While home-based balance exercises are recommended to reduce the risk of falling and fractures in older adults, adherence to exercise remains suboptimal. The long-term objective of this research is to advance body-worn sensor techniques to measure at-home exercise performance and promote adherence. In this study, a method of distinguishing 5 types of walking using hip- and ankle-worn accelerometers was developed and evaluated in a target clinical population. A secondary objective was to evaluate the method's sensitivity to sensor placement. Eighteen community-dwelling, older females (≥50 years) with low bone mass wore triaxial accelerometers at the left hip and each ankle while performing 5 walking tasks at home: 4 walking balance exercises (figure 8, heel-toe, sidestep, backwards) and straight-line walking. Sensor data were separated into low (0.5-2Hz) and high (2-10Hz) frequency bands, and root-mean-square values (energy) were computed for each sensor, axis, and band. These 18 energy estimates were used as inputs to a neural network classifier with 5 outputs, corresponding to each task. Using a leave-one-out cross-validation protocol, the neural network correctly classified 82/90 test instances (91% accuracy). Compared to random selection accuracy of 20% (i.e., 1 in 5), the results indicated excellent separation between tasks. Reducing the sensor set to one hip and one ankle resulted in 6.7-8.9% reduction in accuracy. Our findings can be used in the development of tools used to deliver exercise performance metrics (e.g., % completed) or recognize walking and balance exercise activities using body-worn accelerometers.<p />  <p>Language: en</p>
LA  - en
SN  - 0966-6362
UR  - http://dx.doi.org/10.1016/j.gaitpost.2013.11.015
ID  - ref1
ER  -