1st Joint ESMAC-GCMAS Meeting - Análise de Marcha

O-19
RELIABILITY AND VALIDITY OF AN ACTIVITY MONITOR (IDEEA®) IN A
PAEDIATRIC POPULATION.
Mackey, Anna, Dr; Hewart, Penny; Walt, Sharon, Dr; Moreau, Megan and Stott, Susan,
Associate Professor. University of Auckland Gait Laboratory, Auckland, New Zealand
Summary / conclusions
This pilot study demonstrated that the IDEEA® activity monitor has moderate to high levels of
reliability detecting everyday activities in a normal paediatric population. Concerns were
highlighted in the accurate detection of walking and gait parameters such as, step length and
cadence which need to be addressed prior to use in a pathological patient population.
Introduction
Three-dimensional gait analysis (3-DGA) provides excellent quantitative, reliable measures of
gait abnormalities and is used to determine and monitor orthopaedic surgical interventions in
children with cerebral palsy. However, the gait analysis lab setting is an artificial environment
and it is unknown how changes measured by 3-DGA reflect in the child’s community
performance. Recently a light-weight, wearable device (IDEEA®, MiniSun LLC 1 ) has shown
high reliability in adults in quantifying community walking and levels of daily activity 2 . This
portable system allows the assessment of both temporo-spatial gait parameters and a range of
functional activities, using a 5 triaxial accelerometer system 1 . As yet, there is no information
regarding the function of this IDEEA® device in the paediatric population. The aim of this
paper is to i) present preliminary reliability and validity findings on a comparison of gait
parameters determined from the IDEEA® to those collected simultaneously during a 3-DGA
and ii) determine the level of accuracy of the IDEEA® in identifying activities in a group of
control children. Future studies aim to examine the reliability of this device in children with
cerebral palsy in the community setting.
Statement of clinical significance
In accordance with World Health Organisation guidelines, clinicians are encouraged to assess
clinical outcome in terms of changes in the person’s activity levels and participation 3 . The
IDEEA® could be used to monitor the child’s functional ability in the community following
surgical and rehabilitation interventions.
Methods
Ethical approval was obtained for 12 control children. Part 1 of the study compared the gait
parameters of velocity (metres/second), stride length (metres), step length (metres) and cadence
(steps/minute) obtained from the IDEEA® to those simultaneously collected from a 3-DGA.
Part 2 determined the accuracy of the IDEEA® in detecting 5 activities including: walking,
stairs, standing, sitting and lying. The IDEEA® consists of a small box clipped to the
waistband with 5 sensors attached to the legs, feet and trunk. Once attached the IDEEA® is
calibrated before each measurement session. A stopwatch was started as soon as the IDEEA®
recording began to allow precise matching to 3-DGA and recorded activities. The children first
completed a 3-DGA with both the IDEEA® on and 21 retro-reflective markers required for 3-
DGA. Children completed a 10 metre walk six times, with data collected on a Vicon
Workstation (version 5.0) at 60HZ. Subjects then completed a set protocol of 4 activities,
progressing from a position of supine lying to sitting and then standing, maintaining each
position for 30 seconds. Subjects then walked up and down a flight of stairs. The identification
of walking activity was obtained from the previous 3-DGA walks. Each child completed two
identical data collections, one week apart at the University of Auckland Gait Laboratory. The
percentage accuracy of the IDEEA® in determining each of the 5 activities was calculated by
comparing the recorded time that the subject performed each activity with the IDEEA® output
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