Asymmetry of Upper Limb Activity in Children with Congenital Hemiplegia: Validation of a Triaxial Accelerometer Approach

This study aims to validate the triaxial accelerometer as a tool for measuring upper limb activity by exploring the relationship between the asymmetry index (i.e. the difference of the mean activity of each upper limb, obtained from the analysis of the accelerometer data), the Assisting Hand Assessment (AHA: a test of bimanual activity) score and the Manual Ability Classification System (MACS: a classification of the manual capability) level, in children with hemiplegic cerebral palsy (HCP). A systematic review of literature came first, exploring to what extent the amount of upper limbs activity of both healthy and children with disability can be reliably recorded and compared with each other, using a combination of multiple wearing inertial sensors (as accelerometers), in order to legitimize their use as feasible measurement in the experimental part of the study. The main conclusion of the review was that the use of inertial sensors worn simultaneously on both upper extremities is a valid tool for assessing upper motor activities and asymmetry, both in experimental and real-world conditions. For the clinical study, 14 children with HCP (9 male) and 8 control (6 males) were enrolled and assessed at mean age 9.74 years (standard deviation 3.22) at the Stella Maris Research Centre, Pisa - Italy and at the Queensland Cerebral Palsy and Rehabilitation Research Centre, Brisbane - Australia. Upper limb activity was assessed using two Actigraph triaxial accelerometers, worn on each wrist in two different situation: (i) while performing the Assisting Hand Assessment (AHA); and (ii) during a seven day record, performed with a diary completed for all daytime hours of weartime. Accelerometer data were collected at 80Hz and 1 second epochs, and summarized in Average Counts. The mean activity of the two upper limbs was analysed separately and compared with each other by non-parametric tests. Comparing the mean activity of the two hands of the same group, the dominant one showed higher values, in the both groups, but, as expected, it reached a statistically significant difference only in the HCP group (pTD= 0.75; pHCP< 0.0001). Accordingly with these results, the difference between the non dominant hands of the TD and HCP groups was statistically significant (p<0.0001), contrary to the comparison between the dominant hands (p=0.133). In addition, also the asymmetry index (AI) obtained for the HCP group was significantly higher (p<0.0001) than the one of the TD group. Moreover, comparing the MACS level and the AI during AHA, it was possible to distinguish 4 different clusters of upper limb motor ability (TD group, MACS I, II, and III groups). A further analysis was performed to investigate the relationship among data, using linear regression. The AI during AHA showed a high correlation with the AHA score (R2= .795; p<0.0001). The AI was calculated also considering the 7days data collection, for 16 (n=5 TD, n=11 HCP) participants of the whole sample, and it showed a high correlation with the AI during AHA (R2= .935; p<0.0000001). As a result, these data are very promising about the introduction of accelerometer approach as a reliable new objective and not invasive assessment tool for measuring the upper limb activity. It could become a new suitable common device to monitor, to evaluate and to tailor rehabilitation programs in children with HCP

Actigraph assessment for measuring upper limb activity in unilateral cerebral palsy

Background: Detecting differences in upper limb use in children with unilateral cerebral palsy (UCP) is challenging and highly dependent on examiner experience. The recent introduction of technologies in the clinical environment, and in particular the use of wearable sensors, can provide quantitative measurement to overcome this issue. This study aims to evaluate ActiGraph GT3X+ as a tool for measuring asymmetry in the use of the two upper limbs (ULs) during the assessment with a standardized clinical tool, the Assisting Hand Assessment (AHA) in UCP patients aged 3-25 years compared to age-matched typically developing (TD) subjects. Methods: Fifty children with UCP and 50 TD subjects were assessed with AHA while wearing ActiGraphs GT3X+ on both wrists. The mean activity of each hand (dominant and non-dominant, MA and MA , respectively) and the asymmetry index (AI) were calculated. Two linear mixed model analyses were carried out to evaluate how dependent actigraphic variables (i.e. MA and AI) varied by group (TD vs UCP) and among levels of manual ability based on Manual Ability Classification System (MACS). In both models age, sex, side of hemiplegia, presence/absence of mirror movements were specified as random effects. Results: The MA was significantly lower in UCP compared to TD, while the AI was significantly higher in UCP compared to TD. Moreover, in UCP group there were significant differences related to MACS levels, both for MA and AI. None of the random variables (i.e. age, sex, side, presence/absence of mirror movements) showed significant interaction with MA and AI. Conclusions: These results confirm that actigraphy could provide, in a standardized setting, a quantitative description of differences between upper limbs activity. Trial registration: ClincalTrials.gov, NCT03054441. Registered 15 February 2017

Assessment of upper limb use in children with typical development and neurodevelopmental disorders by inertial sensors: A systematic review

© 2018 The Author(s). Understanding development of bimanual upper limb (UL) activities in both typical and atypical conditions in children is important for: i) tailoring rehabilitation programs, ii) monitoring progress, iii) determining outcomes and iv) evaluating effectiveness of treatment/rehabilitation. Recent technological advances, such as wearable sensors, offer possibilities to perform standard medical monitoring. Body-worn motion sensors, mainly accelerometers, have shown very promising results but, so far, these studies have mainly focused on adults. The main aim of this review was to report the evidence of UL activity of both typically developing (TD) children and children with neurodevelopmental disorders (NDDs) that are reliably reported and comparable, using a combination of multiple wearable inertial sensors, both in laboratory and natural settings. Articles were selected from three research databases (PubMed, Web of Science and EBSCO). Included studies reported data on children aged 0-20 years old simultaneously wearing at least two inertial sensors on upper extremities. The collected and reported data were relevant in order to describe the amount of physical activity performed by the two ULs separately. A total of 21 articles were selected: 11 including TD, and 10 regarding NDDs. For each article, a review of both clinical and technical data was performed. We considered inertial sensors used for following aims: (i) to establish activity intensity cut-points; (ii) to investigate validity and reliability of specified markers, placement and/or number of inertial sensors; (iii) to evaluate duration and intensity of natural UL movements, defined motor tasks and tremor; and (iv) to assess efficacy of certain rehabilitation protocols. Our conclusions were that inertial sensors are able to detect differences in use between both hands and that all reviewed studies support use of accelerometers as an objective outcome measure, appropriate in assessing UL activity in young children with NDDs and determining intervention effectiveness. Further research on responsiveness to interventions and consistency with use in real-world settings is needed. This information could be useful in planning UL rehabilitation strategies