Kinematic Variability and Accelerometers Demonstrate a Lack of Agreement
Advisor Information
Sara Myers
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
7-3-2014 1:00 PM
End Date
7-3-2014 4:00 PM
Abstract
Analysis of human movement variability has provided insights into motor coordination. It has been suggested that an optimal range of variability is preferred in biological systems. Deviations away from optimal have been associated with aging and pathology. Current methods for assessing gait variability are limited to a laboratory setting. A portable method for assessing gait variability could be very useful in the clinical setting. An accelerometer is a small portable device that quantifies acceleration in the vertical direction. The purpose of this study is to determine the agreement between gait variability obtained from an accelerometer and through laboratory-based gait analysis. A total of 19 participants (Age:27±4.9yrs, Mass:69.8±23.0kg, Height:165.9±38cm, Speed:2.9±0.4mph) were recruited for this study. Participants walked on a treadmill at a self-selected speed for 10 minutes while 3D kinematic and right hip accelerometer data was collected. The largest Lyapunov Exponent (LyE) was used to quantify structure of variability. LyE was calculated from the ankle, knee, and hip joint flexion/extension time series and from the vertical acceleration time series. A Bland-Altman statistical test was performed to assess the agreement and repeatability of variability between gait and accelerometer measures. The results indicate a lack of agreement between variability measures of gait and accelerometer while walking on a treadmill. This disagreement indicates that caution should be used when translating laboratory-based measures to the clinical setting using mobile devices. Further work is needed to investigate agreement between variability of data obtained from portable devices and through gait analysis collected in the laboratory.
Kinematic Variability and Accelerometers Demonstrate a Lack of Agreement
Dr. C.C. and Mabel L. Criss Library
Analysis of human movement variability has provided insights into motor coordination. It has been suggested that an optimal range of variability is preferred in biological systems. Deviations away from optimal have been associated with aging and pathology. Current methods for assessing gait variability are limited to a laboratory setting. A portable method for assessing gait variability could be very useful in the clinical setting. An accelerometer is a small portable device that quantifies acceleration in the vertical direction. The purpose of this study is to determine the agreement between gait variability obtained from an accelerometer and through laboratory-based gait analysis. A total of 19 participants (Age:27±4.9yrs, Mass:69.8±23.0kg, Height:165.9±38cm, Speed:2.9±0.4mph) were recruited for this study. Participants walked on a treadmill at a self-selected speed for 10 minutes while 3D kinematic and right hip accelerometer data was collected. The largest Lyapunov Exponent (LyE) was used to quantify structure of variability. LyE was calculated from the ankle, knee, and hip joint flexion/extension time series and from the vertical acceleration time series. A Bland-Altman statistical test was performed to assess the agreement and repeatability of variability between gait and accelerometer measures. The results indicate a lack of agreement between variability measures of gait and accelerometer while walking on a treadmill. This disagreement indicates that caution should be used when translating laboratory-based measures to the clinical setting using mobile devices. Further work is needed to investigate agreement between variability of data obtained from portable devices and through gait analysis collected in the laboratory.