Accelerometry-Based Metrics to Evaluate the Relative Use of the More Affected Arm during Daily Activities in Adults Living with Cerebral Palsy

Abstract

Adults living with cerebral palsy (CP) report bimanual and unimanual difficulties that interfere with their participation in activities of daily living (ADL). There is a lack of quantitative methods to assess the impact of these motor dysfunctions on the relative use of each arm. The objective of this study was to evaluate the concurrent and discriminative validity of accelerometry-based metrics when used to assess bimanual and unimanual functions. Methods: A group of control subjects and hemiplegic adults living with CP performed six ADL tasks, during which they were wearing an Actigraph GT9X on each wrist and being filmed. Four bimanual and unimanual metrics were calculated from both accelerometry-based and video-based data; these metrics were then compared to one other with an intraclass correlation coefficient (ICC). Some of these metrics were previously validated in other clinical population, while others were novel. The discriminative validity was assessed through comparisons between groups and between tasks. Results: The concurrent validity was considered as good to excellent (ICC = 0.61–0.97) depending on the experience of the raters. The tasks made it possible to discriminate between groups. Conclusion: The proposed accelerometry-based metrics are a promising tool to evaluate bimanual and unimanual functions in adults living with CP.

Optimizing Epoch Length and Activity Count Threshold Parameters in Accelerometry: Enhancing Upper Extremity Use Quantification in Cerebral Palsy

“…Two groups of participants were recruited for this study: a group of adults with CP (Adult Group) and a group of children with CP (Children Group). The Adult Group had previously been studied in [ 13 ]. The Adult Group was recruited through the Université Laval mailing list and by consulting health records of the Centre intégré universitaire de santé et de services sociaux de la Capitale-Nationale (CIUSSS-CN).…”

“…The tasks were chosen to cover a variety of bilateral and unilateral UE uses. The tasks and the discriminative value of the tasks were already described in [ 13 ].…”

“…The ratings obtained from video processing were then interpolated to generate data equivalent to 100 frames/second, enabling a comparison with accelerometry data. In the case of the Adult Group, the inter-rater reliability of the quantification method had already been demonstrated in [ 13 ] leading to only one evaluator (IP) processing the video. However, inter-rater reliability was not previously assessed in children performing the Assisting Hand Assessment.…”

“…Alternatively, wrist-worn accelerometers allow the objective quantification of UE use in daily life. They have been validated in healthy subjects and in several populations with neurological disorders (i.e., concurrent validity and inter-rater reliability), including stroke and cerebral palsy (CP) [ 11 , 12 , 13 , 14 ]. Most commercially available movement quantification devices measure movements (accelerations) in three axes and convert them into arbitrary units called activity counts ( AC ) over a predefined time epoch.…”

“…While very interesting from a methodological perspective, setting an arm-specific threshold in each patient is currently not applicable to clinical practice. An experiment conducted by our team also demonstrated the validity of a higher threshold of ≥100 AC per 1 s epoch in adults with unilateral CP [ 13 ] when aiming to characterize various unimanual and bimanual metrics, including the use ratio ( UR ) which has been widely used in clinical studies [ 14 ].…”