Cain C. T. Clark

A Review of Emerging Analytical Techniques for Objective Physical Activity Measurement in Humans

Physical inactivity is one of the most prevalent risk factors for non-communicable diseases in the world. A fundamental barrier to enhancing physical activity levels and decreasing sedentary behavior is limited by our understanding of associated measurement and analytical techniques. The number of analytical techniques for physical activity measurement has grown significantly, and although emerging techniques may advance analyses, little consensus is presently available and further synthesis is therefore required. The objective of this review was to identify the accuracy of emerging analytical techniques used for physical activity measurement in humans. We conducted a search of electronic databases using Web of Science, PubMed, and Google Scholar. This review included studies written in English and published between January 2010 and December 2014 that assessed physical activity using emerging analytical techniques and reported technique accuracy. A total of 2064 papers were initially retrieved from three databases. After duplicates were removed and remaining articles screened, 50 full-text articles were reviewed, resulting in the inclusion of 11 articles that met the eligibility criteria. Despite the diverse nature and the range in accuracy associated with some of the analytic techniques, the rapid development of analytics has demonstrated that more sensitive information about physical activity may be attained. However, further refinement of these techniques is needed.

Quantitative Time-Profiling of Children's Activity and Motion.

Introduction The aim of this study was to establish childrens mechanical movement patterns during a standardized assessment of fitness by using an accelerometer. Further to this, our objective was to use the information from the accelerometer to profile individual time courses of exercise, across the cohort. Methods A multistage fitness test study was performed with 103 children (mean ± SD age = 10.3 ± 0.6 yr). Children wore an ankle-mounted accelerometer, and gait data were collected on radial acceleration traces obtained at a frequency of 40 Hz. Time-resolved metrics of foot impact force, maximum leg lift angle, and stride frequency were used to profile childrens performance across the test duration. A whole-history metric of stride quality, based on the changing ratio of stride length to stride frequency, was used in bivariate analyses of physical performance and body metrics. Results Stride angle derived by our protocol was found to have a strong positive correlation with integrated acceleration, synonymous with counts, widely used in the sport science community (r = 0.81, 0.79, and 0.80 across different stages of the multistage fitness test). Accelerometer data show that differing performance in the test is related to the childrens ability to accurately control their gait, with high performers displaying a linearly increasing speed, delivered through stride extension and well matched to the demand level of the test. A negative correlation was found between stride quality and body measures of body mass index (r = −0.61) and body mass (r = −0.60). Conclusion Profiles of the gait parameters provide information on the mechanics of childs motion, allowing detailed assessment of multiple parameter during increasing intensities of exercise.

A Kinematic Analysis of Fundamental Movement Skills

Abstract Fundamental movement skills are considered the basic building blocks for movement and provide the foundation for specialized and sport-specific movement skills required for participation in a variety of physical activities. However, kinematic analyses of fundamental movement has not been performed. The aims of this study were to, (1) characterise the relationship between facets of fundamental movement and, (2) characterise the relationship between overall integrated acceleration and three-dimensional kinematic variables whilst performing fundamental movement skills. Eleven participants (10±0.8y, 1.41±0.07m, 33.4±8.6kg, body mass index; 16.4±3.1 kg·m2) took part in this study, had anthropometric variables recorded and performed a series of fundamental movement tasks, whilst wearing a tri-axial accelerometer and were recorded using a three-dimensional motion capture system. Maximum shoulder external rotation (°) and maximum shoulder internal rotation velocity (°.s−1) (r=0.86, p<0.001), mediolateral centre of mass range (cm) and centre of mass coefficient of variation (%) (r=0.83, p<0.001), maximum stride angle (°) in the jog and walk (r=0.74, p=0.01) and maximum sprint stride angle and maximum shoulder internal rotation velocity (°.s−1) (r=0.67, p<0.02) were significantly correlated. Maximum sprint stride angle (hip: r=0.96, p<0.001, ankle: r=0.97, p<0.001) and maximum internal rotation velocity (ankle: r=0.6, p=0.05) were significantly correlated to overall integrated acceleration. Overall integrated acceleration was comparable between participants (CV: 10.5), whereas three-dimensional variables varied by up to 65%. Although overall integrated acceleration was comparable between participants, three-dimensional variables were much more varied. Indicating that although overall activity may be correspondent, the characteristics of a child’s movement may be highly varied.

Profiling Movement and Gait Quality Characteristics in Pre-School Children

ABSTRACT There is a dearth of suitable metrics capable of objectively quantifying motor competence. Further, objective movement quality characteristics during free play have not been investigated in pre-school children. The aims of this study were to characterize childrens free play physical activity and investigate how gait quality characteristics cluster with free play in pre-school children (3–5 years old). Sixty-one children (39 boys; 4.3 ± 0.7 years, 1.04 ± 0.05 m, 17.8 ± 3.2 kg) completed the movement assessment battery for children and took part in free play while wearing an ankle- and hip-mounted accelerometer. Characteristics of movement quality were profiled using a clustering algorithm. Spearmans rho and the Mann-Whitney U tests were used to assess relationships between movement quality characteristics and motor competence classification differences in integrated acceleration and spectral purity, respectively. Significant differences were found between motor competency classifications for spectral purity and integrated acceleration (p < .001). Spectral purity was hierarchically clustered with motor competence and integrated acceleration. Significant positive correlations were found between spectral purity, integrated acceleration and motor competence (p < .001). This is the first study to report spectral purity in pre-school children and the results suggest that the underlying frequency component of movement is clustered with motor competence.

SlamTracker Accuracy under Static and Controlled Movement Conditions

Abstract Accelerometry is the de facto standard in objective physical activity monitoring. However traditional accelerometer units undergo proprietary pre-processing, resulting in the ‘black-box’ phenomenon, where researchers are unaware of the processes and filters used on their data. Raw accelerometers where all frequencies related to human movement are included in the signal, would facilitate novel analyses, such as frequency domain analysis and pattern recognition. The aim of this study was to quantify the mean, standard deviation and variance of the SlamTracker raw accelerometer at a range of speeds. Four tri-axial accelerometers underwent a one minute static condition test nine movement condition tests. Accelerometers were assessed for mean, standard deviation, sample variance and coefficient of variation throughout in all axes for all experimental conditions. The sample variance was <0.001g across all speeds and axes during the movement condition tests. In conclusion, the SlamTracker is shown to be an accurate and reliable device for measuring the raw accelerations of movement.

A preliminary audit of medical and aid provision in English Rugby union clubs: compliance with Regulation 9

BackgroundGoverning bodies are largely responsible for the monitoring and management of risks associated with a safe playing environment, yet adherence to regulations is currently unknown. The aim of this study was to investigate and evaluate the current status of medical personnel, facilities, and equipment in Rugby Union clubs at regional level in England.MethodsA nationwide cross-sectional survey of 242 registered clubs was undertaken, where clubs were surveyed online on their current medical personnel, facilities, and equipment provision, according to regulation 9 of the Rugby Football Union (RFU).ResultsOverall, 91 (45. 04%) surveys were returned from the successfully contacted recipients. Of the completed responses, only 23.61% (n = 17) were found to be compliant with regulations. Furthermore, 30.56% (n = 22) of clubs were unsure if their medical personnel had required qualifications; thus, compliance could not be determined. There was a significant correlation (p = −0.029, r = 0.295) between club level and numbers of practitioners. There was no significant correlation indicated between the number of practitioners/number of teams and number of practitioners/number of players. There were significant correlations found between club level and equipment score (p = 0.003, r = −0.410), club level and automated external defibrillator (AED) access (p = 0.002, r = −0.352) and practitioner level and AED access (p = 0.0001, r = 0.404). Follow-up, thematic analysis highlighted widespread club concern around funding/cost, awareness, availability of practitioners and AED training.ConclusionThe proportion of clubs not adhering overall compliance with Regulation 9 of the RFU is concerning for player welfare, and an overhaul, nationally, is required.