A smart-device based motor function battery
Date
2018
Authors
Monaghan, Patrick G., author
Tracy, Brian L., advisor
Fling, Brett W., committee member
Stephens, Jaclyn, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
Growth in the older population will increase the overall impact of age-related neurological disorders. Aging and neurological conditions share features such as impaired motor function and physical dysfunction including reduced muscle strength and power, slowness of movement, increased movement variability and balance dysfunction. Successful performance of daily activities and maintenance of mobility is key to independence and quality of life. Therefore, tracking changes in physical function is critical in gauging quality of life. However truly quantitative measures of physical capacity often require the use of expensive, lab-based equipment. Smart devices contain sensitive tri-axial accelerometers and gyroscopes that measure acceleration and rotation and offer a more cost-effective, portable yet still quantitative means of physical assessment. The purpose is to describe an iPod Touch-instrumented test battery designed to assess features of physical and motor function often shared by normal aging and age-related movement disorders. We have been assessing the correlation between measures taken from expensive lab devices and the iPod Touch smart device for a variety of movements. We developed and tested a multi-item smart device-based battery of motor tasks that addresses motor variability, slowness and postural instability across a range of young, healthy college students. By changing the location of the device we can assess upper and lower limb movement speed and power, hand tremor, or postural control. We have also used previously validated lab devices concurrently with the smart device, which allows us to correlate the results between devices to assess the extent of the association between devices. Outcomes such as peak acceleration and variability of movements can be obtained. Generally, the smart device demonstrated strong correlations with the lab grade sensors for all motor tasks. Furthermore, the smart device was also correlated with the accelerometer across a large range of speed and variability. Strong correlations were seen in ballistic arm and leg tasks, tremor, and postural control assessments. This finding suggests that the smart device can sufficiently assess a broad range of functional capacity. This battery can then be used to study populations exhibiting motor impairment, ranging from older adults, to neurological patients. Using the sensors on the smart device, this testing can be administered remotely and inexpensively by non-experts, providing cost-effective, mobile, user- and patient-friendly physical function testing. More importantly, accessibility of testing is increased while retaining quantitative precision. This should aid in quantifying disease progression and response to pharmacological or exercise/rehabilitative intervention, with the goal of improved function and quality of life in those with impairment.