Physical activity, motor competence and movement and gait quality: A principal component analysis.
OBJECTIVE
While novel analytical methods have been used to examine movement behaviours, to date, no studies have examined whether a frequency-based measure, such a spectral purity, is useful in explaining key facets of human movement. The aim of this study was to investigate movement and gait quality, physical activity and motor competence using principal component analysis.


METHODS
Sixty-five children (38 boys, 4.3 ± 0.7y, 1.04 ± 0.05 m, 17.8 ± 3.2 kg, BMI; 16.2 ± 1.9 kg∙m2) took part in this study. Measures included accelerometer-derived physical activity and movement quality (spectral purity), motor competence (Movement Assessment Battery for Children 2nd edition; MABC2), height, weight and waist circumference. All data were subjected to a principal component analysis, and the internal consistency of resultant components were assessed using Cronbach's alpha.


RESULTS
Two principal components, with excellent internal consistency (Cronbach α >0.9) were found; the 1st principal component, termed "movement component", contained spectral purity, traffic light MABC2 score, fine motor% and gross motor% (α = 0.93); the 2nd principal component, termed "anthropometric component", contained weight, BMI, BMI% and body fat% (α = 0.91).


CONCLUSION
The results of the present study demonstrate that accelerometric analyses can be used to assess motor competence in an automated manner, and that spectral purity is a meaningful, indicative, metric related to children's movement quality.
['Clark|Cain C T|CCT|', 'Barnes|Claire M|CM|', 'Duncan|Michael J|MJ|', 'Summers|Huw D|HD|', 'Stratton|Gareth|G|']
D061725:Accelerometry D000886:Anthropometry D001835:Body Weight D002648:Child D002657:Child Development D002675:Child, Preschool D015444:Exercise D005260:Female D005684:Gait D006801:Humans D008297:Male D009048:Motor Skills D009068:Movement D025341:Principal Component Analysis D055105:Waist Circumference
Physical activity Motor competence Principal component analysis Motor development Pre-school