Article

Rett syndrome is a pervasive neurological disorder with impaired gait
as one criterion. This study investigated the capacity of three
accelerometer-type devices to measure walking activity in Rett syndrome. METHODS:
Twenty-six participants (mean 18 years, SD 8) wore an Actigraph, ActivPAL and
StepWatch Activity Monitor (SAM) during a video-taped session of activities.
Agreement was determined between step-counts derived from each accelerometer and
observation. Repeatability of SAM-derived step counts was determined using pairs
of one-minute epochs during which the same participant was observed to walk with
the same cadence. RESULTS: The mean difference (limit of agreement) for the
Actigraph, ActivPAL and SAM were -41 (SD 33), -16 (SD 21) and -1 (SD 16)
steps/min, respectively. Agreement was influenced by a device/cadence interaction
(p < 0.001) with greater under-recording at higher cadences. For SAM data,
repeatability of step-count pairs was excellent (intraclass correlation
coefficient 0.91, 95% CI 0.79-0.96). The standard error of measurement was 6
steps/min and we would be 95% confident that a change >/=17 steps/min would be
greater than within-subject measurement error. CONCLUSIONS: The capacity of the
SAM to measure physical activity in Rett syndrome allows focus on
participation-based activities in clinical practice and clinical trials.
Implications for Rehabilitation Many girls and women with Rett syndrome are able
to walk on their own or with assistance but with altered movement patterns.
Validated measures of physical activity, such as step counts, have potential to
monitor function during daily life. Compared with other forms of
accelerometer-type devices, such as ActiGraph and ActivPAL, the StepWatch
Activity Monitor (SAM) measured step counts with good accuracy and repeatability.
The capacity of the SAM to measure physical activity in Rett syndrome allows
focus on participation-based activities in clinical practice and clinical trials.

Langue : ANGLAIS