Motor skill competence and moderate- and vigorous-intensity physical activity: a linear and non-linear cross-sectional analysis of eight pooled trials.

BACKGROUND: Few studies have examined the relationship between motor skill competence and device-measured physical activity in large samples and none have used non-linear modelling. This study assessed the linear and non-linear associations between motor skill competence and physical activity in children using pooled data from eight studies. METHODS: Cross-sectional ActiGraph accelerometer and motor skills competence data from 988 children (50.8% boys) aged 3-11 years were included. Total, object control and locomotor skill competence were assessed using the Test of Gross Motor Skill Development. Linear mixed models were fitted to examine linear associations between motor skill competence and physical activity. Then, restricted cubic splines models were used to assess potential non-linear relationships. Interactions by sex and age were assessed. RESULTS: There was evidence of positive linear associations between total skill, and object control and locomotor skills, with moderate- and vigorous-intensity physical activity; however, the associations with total skill competence and object control better fitted a non-linear model. Non-linear models indicated associations were positive but relatively weak in the low to mid ranges of TGMD/object control scores but at high ranges (~ > 70 out of 100/ and ~ 35 out of 50) the association strength increased for both moderate- and vigorous-intensity physical activity. There were sex interactions for locomotor skills only, specifically for vigorous activity with boys having a stronger positive association than girls. CONCLUSIONS: There appears to be a threshold for object control skill proficiency that children need to reach to enhance their physical activity levels which provides support for a motor skill "proficiency barrier". This provides a tangible benchmark for children to achieve in motor competence programs.

Brief clinical report: deletion of the long arm of chromosome 11, [del(11)(q23)].

We report sporadic occurrence of deletion of the long arm of chromosome 11 (q23 leads to qter) in a male newborn infant with intrauterine growth retardation, craniofacial, cardiac, and orthopedic abnormalities and neonatal death but without genital abnormalities. This deletion is seen predominantly in females; here we emphasize the importance of an XX sex chromosome constitution as a factor determining phenotypic expression of and survival in the del(11q) syndrome. We also provide a description of the cardiovascular system from postmortem examination. The cardiac findings are similar to those of two previously autopsied cases and will assist in early clinical diagnosis of the 11q-syndrome.

Partial trisomy 5 with a carrier parent t(5p-;9p+).

The significance of partial trisomies of the B group is as yet unknown. An infant with multiple congenital anomalies was found to have a partial trisomy 5p+ syndrome. The father of this patient demonstrated a 5/9 translocation carrier state. A discussion of the relationship of the partial 5p+ syndrome to the Cri du chat syndrome is noted. Partial trisomy 5 would not appear, as yet, to represent a clearly definable syndrome.