Validity of Accelerometry to Measure Physical Activity Intensity in Children With an Acquired Brain Injury

Emerging methods for measuring physical activity using accelerometry in children and adolescents with neuromotor disorders: a narrative review

BACKGROUND

Children and adolescents with neuromotor disorders need regular physical activity to maintain optimal health and functional independence throughout their development. To this end, reliable measures of physical activity are integral to both assessing habitual physical activity and testing the efficacy of the many interventions designed to increase physical activity in these children. Wearable accelerometers have been used for children with neuromotor disorders for decades; however, studies most often use disorder-specific cut points to categorize physical activity intensity, which lack generalizability to a free-living environment. No reviews of accelerometer data processing methods have discussed the novel use of machine learning techniques for monitoring physical activity in children with neuromotor disorders.

METHODS

In this narrative review, we discuss traditional measures of physical activity (including questionnaires and objective accelerometry measures), the limitations of standard analysis for accelerometry in this unique population, and the potential benefits of applying machine learning approaches. We also provide recommendations for using machine learning approaches to monitor physical activity.

CONCLUSIONS

While wearable accelerometers provided a much-needed method to quantify physical activity, standard cut point analyses have limitations in children with neuromotor disorders. Machine learning models are a more robust method of analyzing accelerometer data in pediatric neuromotor disorders and using these methods over disorder-specific cut points is likely to improve accuracy of classifying both type and intensity of physical activity. Notably, there remains a critical need for further development of classifiers for children with more severe motor impairments, preschool aged children, and children in hospital settings.

Practitioner-led, peer-group sports intervention combined with a context-focused intervention for children with cerebral palsy: a protocol of a feasibility randomised clinical trial

BACKGROUND

There is a need to investigate relevant, acceptable and feasible approaches that promote participation in leisure-time physical activity for children with cerebral palsy (CP). The aim of this study is to assess the feasibility of a randomised controlled trial comparing a peer-group intervention focused on improving physical literacy (Sports Stars) with the combination of Sports Stars and a context-focused intervention (Pathways and Resources for Engagement and Participation, PREP) for ambulant children with CP in Brazil.

METHODS

In this feasibility trial, 18 ambulant children (aged 6-12 years) with CP will be randomised into two groups (nine per group): (1) Sports Stars and (2) Sports Stars plus PREP. The Sports Stars group will receive 8 weekly group sessions, focusing on developing the physical, social, cognitive and psychological skills required to participate in popular Brazilian sports. The combined Sports Stars and PREP group will receive Sports Stars in addition to eight individual PREP sessions focused on overcoming environmental barriers to participation. The primary outcome will include feasibility measures: willingness to participate in an RCT, eligibility and recruitment rates, maintenance of evaluator blinding, acceptability of screening procedures and random allocation, feasibility of evaluating outcomes, contamination between the groups, intervention adherence, treatment satisfaction, understanding of the intervention and implementation resources. Additional instruments will be applied to obtain data related to leisure-time physical activity participation goals, overall participation (home, school and community), physical literacy, level of physical activity and family empowerment. Outcomes will be assessed before, after and 12 weeks after intervention.

ETHICS AND DISSEMINATION

This feasibility trial has been approved by ethical Federal University of Minas Gerais' Ethics Review Committee (CAAE: 33238520.5.0000.5149). All potential subjects will provide written informed consent. The results of this study will be published in peer-reviewed journals and be presented at academic conferences.

TRIAL REGISTRATION NUMBERS

RBR-4m3b4b6, U1111-1256-4998.

Time-matched accelerometers on limbs and waist in children with CP give new insights into real-life activities after botulinum toxin treatment: A proof of concept study

PURPOSE

This study aimed to explore the feasibility of using time-matched uniaxial accelerometers for measuring movement in daily life in children with cerebral palsy (CP) before and after botulinum toxin injections.

METHODS

This observational study of clinical care with a pre-post design was set in the home and school environment. Participants included eleven children (4-13 years of age) with CP (GMFCS I-III). The children wore uniaxial accelerometers (ActiGraph, model GT1M) for 4 days on both wrists, the right ankle and around the waist before, 3 weeks and 3 months after BoNT-A injections in the legs. Five children also got BoNT-A in the most affected arm. All injections were given according to clinical indications and routine. The accelerometers were all time-matched to define ambulation, arm swing, voluntary activity of arms, and bimanual activity. The feasibility of wearing accelerometers with this setup was evaluated. A linear mixed model was used for analysis of the percentage time and at which intensity the different activities were performed. The confidence interval demonstrated any difference between the dominant and non-dominant arm.

RESULTS

Time-matching of accelerometers placed on both wrists, the waist, and one ankle is a feasible method of registering ambulation, arm swing during gait, and arm movements while not ambulating. Before injections, the children spent 5.6% of their time ambulating. This value declined to 3.9% at 3 months. Contrary to clinical goals, arm movement did not increase after injecting the most affected arm with BoNT-A, however, injections may have decreased mirror movements, which are often bothersome for the child.

CONCLUSION

A time-matched 4-accelerometer set-up is feasible in children with cerebral palsy. A future study including time-matched multi-axial accelerometers on all four limbs, could provide important information on the effect of BoNT-A in daily life.

Online Awareness among Adolescents with Acquired Brain Injury: Preliminary Findings following Performance of Motor, Cognitive and Functional Tasks

Aims: Online awareness is an ongoing ability to monitor performance within the stream of action. It involves the ability to detect errors emerging during actual performance, as well as to anticipate potential problems. This preliminary within-subject study aimed to evaluate emergent and anticipatory online awareness among adolescents with Acquired Brain Injury (ABI) during performance of motor, cognitive and functional tasks.Methods: 14 adolescents (11-18 years) following ABI were recruited. Before and after completion of the tasks, participants fulfilled task-related awareness questionnaires.Results: In the motor task, no significant correlations were found between heart rate and the subjective perceived exertion scale (emergent awareness). In the cognitive task, no significant correlations were found between the estimated difficulty before the task (anticipatory awareness) and actual performance, however a significant correlation was found between performance and the self-evaluation of performance (emergent awareness), in the easiest item of the task. In the functional task, two main patterns of online awareness were recognized: accurate and overestimation of performance.Conclusions: Online awareness deficits in adolescents after ABI, vary as a function of task characteristics. Clinicians who aim to improve online awareness should direct interventions to mainly include functional tasks, as compared to cognitive and motor tasks.

The Value of High Intensity Locomotor Training Applied to Patients With Acute-Onset Neurologic Injury

Long-standing research in animal models and humans with stroke or incomplete spinal cord injury (iSCI) indicate that specific physical training variables, such as the specificity and amount of practice, may influence neurologic recovery and locomotor function. More recent data highlight the contributions of exercise intensity, as estimated indirectly by cardiovascular exertion, as potentially more important than previously considered. The effects of exercise intensity are well described in neurologically intact individuals, although confusion regarding the definitions of intensity and safety concerns have limited its implementation during physical rehabilitation of patients with neurologic injury. The purpose of this review is to delineate some of the evidence regarding the effects of exercise intensity during locomotor training in patients with stroke and iSCI. We provide specific definitions of exercise intensity used within the literature, describe methods used to ensure appropriate levels of exertion, and discuss potential adverse events and safety concerns during its application. Further details on the effects of locomotor training intensity on clinical outcomes, and on neuromuscular and cardiovascular function will be addressed as available. Existing literature across multiple studies and meta-analyses reveals that exercise training intensity is likely a major factor that can influence locomotor function after neurologic injury. To extend these findings, we describe previous attempts to implement moderate to high intensity interventions during physical rehabilitation of patients with neurologic injury, including the utility of specific strategies to facilitate implementation, and to navigate potential barriers that may arise during implementation efforts.

Validity of accelerometry for predicting physical activity and sedentary time in ambulatory children and young adults with cerebral palsy

Background

/Objectives: This study aimed to validate five published ActiGraph (AG) cut-off points for the measurements of physical activity (PA) and sedentary time (ST) in ambulatory children and young adults with cerebral palsy (CP). Additionally, four energy expenditure (EE) prediction equations based on AG counts and activPAL (AP) steps were examined in this population, using oxygen uptake (VO₂) as the criterion.

Methods

Four male and six female participants with CP (Gross Motor Function Classification System levels I-III, ages 9-21 years) completed seven activities while simultaneously wearing an AG, AP monitor and indirect calorimetry unit. VO₂ was measured on a breath-by-breath basis using the indirect calorimetry and was converted into EE using metabolic equivalents. AG counts were classified as sedentary, light PA (LPA) or moderate-to-vigorous PA (MVPA) using five cut-off points: Puyau, Evenson, Romanzini, Clanchy and Baque. The predicted EE was computed using three AG-based equations (Freedson, Trost and Treuth) and an AP step-based equation.

Results

Based on 1920 available data points from the 10 participants, Baque (r = 0.896, κ = 0.773) and Clanchy (r = 0.935, κ = 0.721) AG cut-off points classified PA and ST most accurately. All the equations overestimated EE during sitting activities and underestimated EE during rapid walking. The Freedson, Treuth and AP equations exhibited systematic bias during rapid walking, as their differences from the criterion measure increased progressively with increasing activity intensity.

Conclusions

The AG accurately classified PA and ST when the Baque and Clanchy cut-off points were used. However, none of the available AG or AP equations accurately predicted the EE during PA and ST in children and young adults with CP. Further development is needed to ensure that both devices can estimate EE accurately in this population.

Association Between Lifestyle Characteristics and Body Mass Index of Mothers of Children With Allergic Diseases

Background

For mothers of children with allergic diseases, the amount of physical activity involved in childcare increases owing to factors, such as the need for diet therapy and environmental improvements. Reportedly, the body mass index (BMI) of mothers of children with food allergies (FAs) is significantly lower than that of those of children without allergies (non-FA mothers). The aim of this study was to evaluate the characteristics of diet and physical activity in FA mothers and to clarify their effects on BMI.

Methods

To investigate the association between lifestyle characteristics and BMI in 69 mothers of children with FA, bronchial asthma and atopic dermatitis, their diets and physical activity pattern (using a three-axis accelerometer) were investigated; dietary and physical activity patterns (every hour) were extracted using principal component analysis, and multiple regression analyses were performed.

Results

Multiple regression analyses revealed a significant positive correlation (P = 0.037) between BMI and the third principal component of dietary patterns (positive correlation with cereals and negative correlation with sweets), a significant negative correlation (P = 0.004) between BMI and FA and the total daily duration of performing low- and moderate-intensity physical activity (P = 0.031) and a significant positive correlation (P = 0.008) between FA and the first principal component of physical activity expenditure patterns (patterns of ongoing physical activity throughout the day). In FA mothers (n = 51), a significant positive correlation (P = 0.042) was observed between the third principal component of dietary patterns and BMI.

Conclusion

Low BMI in FA mothers may be related to reduced cereal intake, increased sweets intake and prolonged and continuous low- and moderate-intensity physical activity.

Developing a Low-Cost Wearable Personal Exposure Monitor for Studying Respiratory Diseases Using Metal-Oxide Sensors

Global industrialization and urbanization have led to increased levels of air pollution. Those with respiratory diseases, such as asthma, are at the highest risk for adverse health effects and reduced quality of life. Studying the relationship between pollutants and symptoms is usually achieved with data from government air quality monitoring stations, but these fail to report the spatial and temporal resolution required to track a person's true exposure, especially when the majority of their time is spent indoors. We develop and build eight wrist-worn wearable devices, weighing only 64 g, to measure known asthma symptom triggers: ozone, total volatile organic compounds, temperature, humidity, and activity level. The devices use commercial off-the-shelf components, costing under $150 each to build. This report focuses on the design, calibration, and testing of the devices. Emphasis is placed on the calibration of a metal-oxide-semiconductor gas sensor for detecting ozone, which is a difficult task because of the large variations in ambient temperature and humidity found when using a wearable device. Examples of testing the devices in four real environments are also discussed: 11 days inside a well-ventilated laboratory, ten days outdoors during the summer, alternating the devices between indoor and outdoor environments to examine their response to quickly changing environments, and a field test where scripted activities are performed for a full day. The work demonstrates a wearable device for environmental health studies and addresses the challenges of existing sensors for real-world applications.