Motor problems in children with severe emotional and behavioural difficulties

Bronagh Taylor1, Donncha Hanna1, and Martin McPhillips2

1 Queen’s University, Belfast2 Edge Hill University

Corresponding author:

Dr Martin McPhillips, Department of Psychology, Edge Hill University, Ormskirk, Lancashire, England, L39 4QP; Email: martin.mcphillips@edgehill.ac.uk

Abstract

Background

There is growing evidence that children with motor difficulties are at risk of psychosocial

problems, and vice versa. However, it is not clear how far different aspects of motor function

are predictive of psychosocial well-being in the context of other powerful factors, such as

family-upset, that are known to affect psychosocial development.

Aims

To investigate the role of basic motor skills and primary reflex persistence in young children

with severe emotional and behavioural difficulties (EBD).

Sample

From a total sample of 225 children, 3 groups were selected; children excluded from school

(severe EBD) (n=29), a male comparison group (n=38) and a female comparison group

(n=45). The groups were matched (at group level) on age, IQ and level of social

disadvantage.

Method

All of the selected children completed a range of standardised motor, cognitive, social and

behavioural measures, as well as a clinical protocol for primary reflex persistence.

Results

Children with severe EBD had significant levels of motor difficulties, primary reflex

persistence and family-upset, as well as significant literacy problems, attention deficits and

raised levels of hyperactivity/impulsivity relative to the comparison groups. A hierarchical

multiple regression analysis revealed that basic motor skills, primary reflex persistence,

family-upset, hyperactivity and literacy were all significant predictors of psychosocial

functioning.

Conclusions

The findings suggest that motor difficulties and primary reflex persistence may act as

independent stressors of psychosocial functioning in children with EBD. We suggest that

specific movement interventions should be adopted to complement existing provision for

children at risk of psychosocial problems.

Keywords: motor difficulties; emotional problems; psychosocial functioning; behavioural

difficulties

Emotional and behavioural difficulties (EBD) is an umbrella term that is commonly

used to describe children with a complex range of psychosocial problems, disruptive

behaviours, and mental health issues. Problems with definition persist across

different educational systems (e.g., Mundschenk & Simpson, 2014), and this has

affected identification and prevalence estimates of EBD. In the UK, recent figures

show that 4.3% of the total school population (1.2% of primary school aged children)

received a fixed period exclusion from mainstream schooling, predominantly for

behavioural problems, indicating severe EBD (Department for Education, 2017). This

is of major concern as the long-term outcomes for children with severe EBD may be

particularly negative (e.g., Siperstein, Wiley, & Forness, 2011).

Children with EBD are at increased risk of co-occurring difficulties that lead to vicious

cycles where the emotional and behavioural difficulties of the child exacerbate or

compound other problems, and vice versa. For example, children with EBD are likely

to experience academic difficulties (e.g., Reid, Gonzalez, Nordness, & Epstein,

2004; Trout, Nordness, Pierce, & Epstein, 2003). This is unsurprising as early

behavioural regulation skills predict preschool literacy, vocabulary and maths skills

and readiness to learn (e.g., Blair & Raver, 2015; McClelland et al., 2007; Razza,

Martin, & Brooks-Gunn, 2012), while literacy difficulties are associated with an

increased risk of psychiatric disorders in children and young adolescents (e.g.,

Carroll, Maughan, Goodman, & Meltzer, 2005).

Recently, a growing body of research has suggested that motor function and

emotional and behavioural difficulties may be associated (e.g., Piek & Rigoli, 2015).

A number of studies have shown that children with developmental coordination

disorder (DCD) may be at risk of internalising problems, such as anxiety and

depression (e.g., Lingam et al., 2012), and externalising behaviours, such as

attention-deficit/hyperactivity disorder (ADHD) (e.g., Kaiser, Schoemaker, Albaret, &

Geuze, 2015).

The ‘elaborated environmental stress hypothesis’ (Cairney, Rigoli, & Piek, 2013), has

been proposed, where it is suggested that motor difficulties act as a primary stressor

on the psychosocial wellbeing of the child. For example, in an observational study of

social and physical play in school playgrounds, involving 55 children with DCD and

55 controls (all aged 6- to 10-years-old), it was found that the children with DCD

spent more time alone or with one other child (Smyth & Anderson, 2000). Further, it

has been shown that, in children with motor difficulties, peer problems may mediate

the risk of behavioural difficulties (Wagner, Bös, Jascenoka, Jekauc, & Petermann,

2012) and internalising problems (Mancini, Rigoli, Roberts, Heritage & Piek, 2018).

In other words, the presence of motor difficulties may act as a primary stressor that

reduces the potential protective factors available to the child, such as positive peer

relations, with subsequent risk of mental health issues.

Conversely, other studies have shown that children with a primary mental health

diagnosis or concern are at risk of experiencing significant levels of motor difficulty

(e.g., Ekornås, Lundervold, Tjus, & Heimann, 2010; Skirbekk, Hansen, Oerbeck,

Wentzel-Larsen, & Kristensen, 2012). This suggests that the relationship between

motor difficulties and psychosocial functioning may reflect complex, bi-directional

processes. In addition, motor difficulties commonly co-occur across a range of

developmental disorders and pathological conditions, including disruptive behaviours

(e.g., Van Damme, Sabbe, van West, & Simons, 2015), and it has been suggested

that motor difficulties may reflect underlying, neurological vulnerability (Dewey &

Bernier, 2016; Gillberg, 2010; Levit-Binun, Davidovitch & Golland, 2013). From this

perspective, factors that compromise early brain development may increase the risk

of motor and psychosocial difficulties, separately or in combination.

Measures of income inequality (such as relative poverty, low socioeconomic status

(SES) and social disadvantage) are strongly associated with a range of suboptimal

neurocognitive, health, economic, educational and socioemotional outcomes (e.g.,

Bradley & Corwyn 2002; Evans, 2016; Farah et al., 2006; Wadsworth & Achenbach,

2005), including literacy problems (e.g., Buckingham, Bearman, & Wheldall, 2014;

Dilnot, Hamilton, Maughan, & Snowling, 2017), motor difficulties (McPhillips &

Jordan-Black, 2007a) and ADHD (Russell, Ford, Rosenberg, & Kelly, 2014). Further,

the negative effects of clusters of adverse childhood experiences (ACEs) on later,

adult health and psychosocial outcomes (e.g., Boullier & Blair, 2018) has become a

major concern for policymakers across the world (e.g., Hughes et al., 2017). There is

also evidence that ACEs impact early motor development (e.g., Roeber, Tober, Bolt,

& Pollak, 2012; Wade, Bowden, & Sites, 2018).

There are some conflicting findings with regard to the structural impact of marked

childhood adversity on specific brain regions, but one of the most consistent findings

is that grey matter volume (GMV) in the cerebellum, a key subcortical region

involved in motor control, may be reduced (e.g., Bauer, Hanson, Pierson, Davidson,

& Pollak, 2009; De Bellis & Kuchibhatla, 2006). Most of this work has focused on the

effects of extreme childhood adversities, including neglect and abuse, but there is

emerging evidence that relatively moderate levels of parental/family discord may

impact cerebellar development. In a structural MRI study of older adolescents, Walsh

et al. (2014) found that there was a significant association between chronic, but

relatively moderate, levels of parental/family discord and reduced GMV across a

number of different brain regions. In particular, there was strong evidence of reduced

GMV in the vermis and midline areas of the cerebellum, which corresponds with

separate work on the neurological correlates of DCD (e.g., Zwicker, Missiuna, &

Boyd, 2009).

In summary, the findings from a wide body of research suggest that the problems

experienced by children with severe EBD are extensive and most likely reflect a

complex interplay of biopsychosocial processes (e.g., Cooper, 2014). From this

perspective, the emotional and behavioural difficulties of the child are unlikely to be

reducible to the impact of single factors. In other words, the elaborated

environmental stress hypothesis, which proposes that motor difficulties act as a

primary stressor on psychosocial functioning, may represent a partial model of

potential factors that may precipitate severe EBD. The findings from the few studies

that have examined motor skills in children who have been excluded from school or

identified with severe EBD suggest that motor difficulties may be common, with

males at particular risk (Hill, Pratt, Kanji, & Jones Bertoli, 2017; Iversen, Knivsberg,

Ellertsen, Nødland, & Larsen, 2006). However, it is not clear to what extent other

commonly co-occurring difficulties, such as ADHD and literacy problems, may have

contributed to the emotional and behavioural difficulties of the children in these

studies. In addition, the role of powerful social factors, such as family-upset, have not

been examined at the same time so that it is difficult to assess the importance of

motor function within a broader biopsychosocial framework.

The present study

The primary aim of the present study was to compare basic motor skills in children

with severe EBD to children from similar socially disadvantaged backgrounds, in the

context of other commonly co-occurring difficulties (attention deficits and

hyperactivity, literacy problems). A measure of an adverse childhood experience

(ACE) was also included (family-upset) in order to examine the importance of basic

motor skills in the context of a powerful social factor that previous research suggests

may impact socioemotional development.

A secondary aim of the study was to capture a broader picture of motor function by

including a clinical measure of primary reflex persistence. Primary reflex persistence

is usually associated with compromised neurological functioning in children with

cerebral palsy (e.g., Agarwal & Verma, 2012). Primary reflex tests are routinely

included as part of the neonatal pediatric motor examination (Zafieriou, 2004), and

the most frequently occurring persistent reflex in children with neurological lesions is

the asymmetric tonic neck reflex (ATNR) (Paine, 1961). The ATNR is a subcortical

response that was first demonstrated in decerebrated cats (Magnus, 1926), and a

similar response may be initiated in the human neonate; when the head is turned to

one side there is increased extensor tonus in the arms and legs on the same side

and flexor tonus in the limbs on the opposing side.

Lateral movement of the head also includes activation of the vestibular system,

which is multimodal with multiple projections to the cerebellum and other brain

regions (Angelaki & Cullen, 2008), including reciprocal projections to areas involved

in social cognition and emotion processing (Gurvich et al., 2013; Deroualle & Lopez,

2014). Vestibular dysfunction is also associated with a range of neurodevelopmental

disorders (Van Hecke et al., 2019).

Primary reflex responses typically diminish during the first year of life (Holt, 1991).

While severe persistence may indicate predominantly intractable organic problems,

such as cerebral palsy, milder persistence has been associated with less severe

motor and cognitive difficulties (e.g., Capute et al., 1984; McPhillips & Jordan-Black,

2007b). Some studies have shown that there may be very low levels of ATNR

activity in some healthy individuals without obvious motor difficulties (e.g., Bruijn et

al., 2013). This suggests that ATNR persistence may be better described on a

continuum, rather than simple presence/absence criteria, where raised levels of

ATNR persistence may be considered a behavioural marker of neurodevelopmental

delay (Morrison, 1985). This is the first study to examine the persistence of primary

reflexes in children with severe EBD.

The main aims of the present study were:

1. To examine basic motor skills and primary reflex persistence in children with

severe EBD;

2. To examine the relative impact of different aspects of motor function (basic

motor skills and primary reflex persistence) on psychosocial functioning in

children with severe EBD, in the context of commonly co-occurring factors

(family-upset, ADHD, and literacy difficulties).

Method

Participants

An independent groups design was used; 3 groups of children (aged 8-11 years)

were matched for age, IQ and levels of social disadvantage at group level. The

severe EBD group consisted of 29 children (all males) (mean age, 10y, 3m)

attending a special school for children with social, emotional and behavioural

difficulties in the Belfast district of N. Ireland. All of the children had been excluded

from mainstream primary schooling for at least 3 months.

A matched comparison group of 38 male children (mean age, 10y, 3m) and a

matched comparison group of 45 female children (mean age, 10y, 5m), with similar

levels of IQ and social disadvantage, were selected from an original sample of 192

children attending 4 mainstream primary schools in disadvantaged areas in the

Greater Belfast district. One-way ANOVAs revealed that there were no significant

differences between the three groups on age, F(2, 109) = 1.17, p =.315, ηp2 =.02, or

IQ scores, F(2, 109) = 0.41, p =.688, ηp2 =.01.

None of the children in the study groups had a diagnosed neurological disorder.

A flow diagram of how the groups were constructed is shown in Figure 1.

Insert Figure 1

Free school meal entitlement was used as an index of social disadvantage; 83% of

the severe EBD group, 87% of the male comparison group and 82% of the female

comparison group were entitled to free school meals. This compares to 31% of

children in the total primary school population in N. Ireland entitled to free school

meals at the time of the study (Department of Education, N. Ireland, 2015).

Measures

Three aspects of family background (death of a parent, lone parenthood or child in

care) were used to index the family status of the children; presence of one or more of

these background factors was used to indicate the presence of a family-upset.

Two subtests (vocabulary and matrix reasoning) from the 4 subtests available in the

Wechsler Abbreviated Scale of Intelligence (WASI-II) (Wechsler, 2011) were used to

provide a measure of full scale IQ. This is an individually administered standardised

test that can be completed in approximately 15 minutes.

The Strengths and Difficulties Questionnaire (SDQ) (Goodman, 1997) was used to

measure psychosocial functioning, and was completed by each child’s teacher. The

subscale scores were combined to provide an overall score. The SDQ has been

used extensively to screen for behavioural, emotional and psychiatric disorders in

children. Meltzer, Gatward, Goodman, and Ford (2000) found that, in a large

population sample of 5-10 year old children, females (N=2433) and males (N=2368)

had mean overall SDQ scores of 5.6 (SD = 5.3) and 8.0 (6.2), respectively.

The Conners 3 (Conners, 2008) was used to screen for levels of

attention-deficit/hyperactivity disorder (ADHD) and was also completed by the

appropriate teacher. The ‘inattention’ and ‘hyperactivity/impulsivity’ subscales were

used in this study as they were thought to be most indicative of ADHD. The Conners

3 is a standardised test with a mean T-score of 50 and a standard deviation of 10.

Scores above 70 indicate clinically significant difficulties for each subscale.

The Wechsler Individual Achievement Test (WIAT-II) (Wechsler, 2005) was used to

provide measures of core literacy skills. This is an individually administered

standardised test, which can be completed in approximately 15 minutes. The word

reading, pseudoword decoding, and spelling subtests were used. The standard

mean for each subtest of the WIAT-II is 100 with a standard deviation of 15. A

combined mean of the 3 subtest scores was used to create an overall basic literacy

composite score for each participant.

The Movement Assessment Battery for Children (MABC-2) (Henderson, Sugden and

Barnett, 2007) was used to provide detailed measures of fine and gross motor skills,

as well as static and dynamic balance, and takes approximately 25 minutes to

complete. Each participant completed 8 age-appropriate tasks; 3 manual dexterity, 2

aiming and catching, and 3 balance tasks. Composite scores were calculated for

manual dexterity, aiming and catching, and balance, as well as an overall motor

skills score and corresponding percentile values. The mean standard score for all

elements of the MABC-2 is 10 with a standard deviation of 3. According to the

MABC-2 test manual, scores in the bottom 5 percentiles (standard score of 5 or

below) represent a definite motor problem requiring motor intervention, and scores

between the 5th and 15th percentiles suggest a degree of difficulty that is borderline

(Henderson et al., 2007).

An adapted Schilder Test protocol was used to provide a measure of persistence of

a primary reflex, the asymmetric tonic neck reflex (ATNR), (Morrison, 1988;

Livingstone & McPhillips, 2014). In the present study head and arm movements were

recorded using the Qualisys Motion Capture System. The participants were asked to

stand at the centre of an arc of LED lights with their arms outstretched directly in

front at shoulder height. The trials began when the light display, which was

programmed to light in sequences either to the left or right, was initiated. Each trial

sequence lasted for 25 seconds and involved one turn of the head from the centre to

the left or right side of the arc, one turn of the head from one side of the arc across to

the other side, and one turn of the head back to the centre. This induced a sideways

rotation of the head at an angular velocity of approximately 0.35 radians per second.

The participants were instructed to keep their arms as still as possible and to

maintain the forward alignment of their arms towards a centrally located green LED

throughout.

Each participant completed two trials with their eyes open followed by two trials with

their eyes closed with the tester moving their head to follow the light sequences. To

avoid order effects, the head turns were counterbalanced. Kinematic measures of

arm and head movements in 3D space were recorded by six Qualisys cameras

suspended on a surrounding frame. The movements of the wrists and the front of the

head were measured using two reflective markers attached to elasticated wristbands

worn on the wrists, and one marker attached to the centre of a glasses frame, which

rested on the bridge of the nose.

The cameras captured at 56 frames per second, and the total extent of movement by

the markers across each formal trial was calculated using MATLAB version 7.6.0.

This was converted to a ratio of total arm movement to total head movement, thus

scaling the amplitude of the arm movement with respect to each individual’s head

rotation.

Procedure

Ethical approval for the study was given by the Research Ethics Committee, N.

Ireland. Parental consent was obtained for all of the children who participated in the

study, and each child gave written and verbal consent at the outset of all of the test

sessions.

Testing was divided into 3 separate sessions. All of the testing was conducted in a

separate, quiet room in each school. In Session 1, the total sample of children

(N=225) completed the WASI-II (Wechsler, 2011). This was used to construct the

comparison groups, which were matched as a group to the children with severe EBD

on age and IQ score. As the IQ levels of the children with severe EBD were relatively

low, male and female comparison participants were allocated on the basis of

proximity to the mean IQ score of this group; in practice, an IQ score of 95 or below

was used as a cut-off. In Session 2, the selected children completed the WIAT-II

(Wechsler, 2005), and in Session 3, the selected children completed the MABC-2

(Henderson et al., 2007) and adapted Schilder Test (Morrison, 1988; Livingstone &

McPhillips, 2014). The questionnaires were completed by the appropriate class

teacher for each selected child. Children at risk of autism spectrum disorders

(undergoing assessment) were excluded from the study.

Data Analysis

The IBM SPSS 23.0 statistical package (IBM Corporation, New York, USA) was

used to analyse the data. An a priori calculation of statistical power, assuming a

large effect size of 0.4, suggested that 3 groups of 30 participants each would

provide 92% power to detect a significant difference (Faul, Erdfelder, Lang, Buchner,

2007). Standard MANOVA and ANOVA procedures, with post hoc Bonferroni tests,

were used to make group comparisons.

A hierarchical multiple regression analysis was used to evaluate the relative

predictive power of six predictors on social-emotional functioning (total SDQ scores).

The predictors were entered in four blocks to reflect the literature outlined earlier,

and, in particular, to assess the additional contribution of motor difficulties and

primary reflex persistence in the context of previously established predictors. Family-

upset (presence of a significant upset in family life; death of a parent, lone parent or

child in care or looked after) was included at step one, inattention and

hyperactivity/impulsivity (T-scores on the two subscales of the Conners 3) were

added at step two; literacy level (composite scores of reading, pseudoword decoding

and spelling) was added at step three: motor skills (total standard scores on the

MABC-2) and ATNR persistence (ratio scores on the eyes closed condition of the

adapted Schilder test) were added at step four. The sample size was deemed

adequate to test if the model, with 6 predictors, was significant (Tabachnick & Fidell,

2007). Correlational analyses revealed that none of the predictors were highly

correlated, and collinearity statistics (Tolerance and VIF) were well within acceptable

limits (Field, 2013). Residual and scatterplots suggested that the assumptions of

normality, linearity and homoscedasticity were all met (Field, 2013).

Results

Family-upset

In total, 27 children with severe EBD (93%) had experienced at least one family-

upset. Twenty-three (79%) lived in a lone parent household following family break-up

(compared to 25% for all families living in the UK (ONS, 2015)). In addition, 4

children (14%) had experienced the death of a parent, with 2 living with the

remaining parent and 2 in care (looked after). In contrast, none of the children in

either comparison group had experienced the death of a parent or was in care.

However, 14 (37%) of the children in the male comparison group and 13 (29%) of

the children in the female comparison group had experienced family break-up. A chi-

square test revealed that there was a significant association between the groups and

the presence of a family-upset, χ2(2) = 32.10, p<.001. Standardised residuals

showed that there was a significantly higher proportion of children with a family-upset

in the severe EBD group; there were no significant differences in proportions with a

family-upset in the male and female comparison groups.

The means and standard deviations of group characteristics and dependent

measures are shown in Table 1.

Insert Table 1

One-way MANOVAs were used initially for analyses of the Conners 3 subscales, the

WIAT-II subtests, the Movement ABC-2 composites, and the arm:head ratios on the

adapted Schilder Test for ATNR persistence to reduce the risk of family-wise error

from multiple ANOVAs.

Conners 3 subscales

A one-way MANOVA revealed that there was a significant effect of group on the

combined variable of the standardised scores for inattention and

hyperactivity/impulsivity subscales, Wilks’ Lambda (Ʌ) = .70, F(4,216) = 10.53, p

<.001, ηp2 =.16.

Wechsler Individual Achievement Test (WIAT-II)

A one-way MANOVA revealed that there was a significant effect of group on the

combined variable of the WIAT-II standardised scores for reading, pseudoword

decoding and spelling, Wilks’ Lambda (Ʌ) = .77, F(6,214) = 4.94, p <.001, ηp2 =.12.

Movement ABC-2 (MABC-2)

A one-way MANOVA revealed that there was a significant effect of group on the

combined variable of the MABC-2 composite scores (manual dexterity, aiming and

catching, and balance), Wilks’ Lambda (Ʌ) = .48, F(6,214) = 15.64, p < .001, ηp2 =.31.

The distribution of total and composite scores for the MABC-2 according to group is

further illustrated in Figure 2.

Insert Figure 2

ATNR persistence

A one-way MANOVA revealed that there was a significant effect of group on the

combined variable of arm:head ratios, Wilks’ lambda (Ʌ) = .82, F(4,216) = 5.50, p

<.001, ηp2 =.09.

The distribution of arm:head movement ratio scores for each of the three groups

across the two conditions of the adapted Schilder Test is further illustrated in Figure

3.

Insert Figure 3

The follow-up ANOVAs for significant MANOVAs, with a summary of the post hoc

analyses, are also presented in Table 1.

Regression analysis

The hierarchical multiple regression showed that at Step 1, family-upset contributed

significantly to the model, F(1,111) = 67.45, p<.001, and accounted for 37% of the

variation in SDQ scores. When inattention and hyperactivity/impulsivity were added

at Step 2, a significant additional 22% of the variation in SDQ scores was explained,

F(3,109) = 53.04, p<.001. When literacy was added at Stage 3, a significant

additional 3% of the variation in SDQ scores was explained, F(4,108) = 44.29,

p<.001. Finally, the addition of basic motor skills and ATNR persistence at Stage 4

explained a significant further 10% of the variation in SDQ scores. In the final model,

F(6,106) = 44.55, p<.001, all of the predictors were significant, with the exception of

inattention (p=.55), and the linear combination of the 6 predictors accounted for 70%

of the variation in SDQ scores (psychosocial functioning). Hyperactivity/Impulsivity

explained the largest unique variation in SDQ scores followed by ATNR persistence.

A summary table of the 4-stage hierarchical multiple regression model is shown in

Table 2.

Insert Table 2

Discussion

The results showed that the children with severe EBD in the present study

experienced a significant level of family-upset (93%) relative to matched control

groups, emphasising the potential impact of family background factors on social-

emotional development.

The results also showed that the children with severe EBD had significantly higher

scores (raised levels of socio-emotional problems) on the Strength and Difficulties

Questionnaire (SDQ) than the male and female comparison groups, which were

matched for IQ and levels of social disadvantage. In fact, 83% of the children with

severe EBD had scores that indicated high (14%) or very high (69%) levels of socio-

emotional difficulty. This suggests that the SDQ provided a good measure of the

emotional and behavioural difficulties experienced by the children with severe EBD

in the present study. Further, the male comparison group had significantly higher

levels of socio-emotional difficulty than the female comparison group; this is in line

with previous work that suggests males score higher than females on this measure

(Meltzer et al., 2000).

The children with severe EBD had significantly higher scores on the inattention and

hyperactivity/impulsivity subscales of the Conners 3 than the male and female

comparison groups, who did not differ significantly on either subscale. On the

hyperactivity/impulsivity subscale, in particular, 62% of the children with severe EBD

showed clinically at-risk scores (above 70), which is unsurprising as these children

were excluded predominantly on the basis of disruptive behaviours. Further, the

comparison groups also showed raised levels of hyperactivity/impulsivity, relative to

normative data, which may reflect the overall high levels of social disadvantage

across the 3 groups (e.g., Russell et al., 2014).

The results also showed that the children with severe EBD had significantly lower

composite literacy scores than the male and female comparison groups, which did

not differ significantly; 59% of the children with severe EBD had literacy levels in the

lowest 10 percentiles in comparison to 26% and 16% for the male and female

comparison groups respectively. This is in line with previous research in children with

severe EBD (e.g., Reid et al., 2004; Trout et al., 2003). The high overall levels of

literacy difficulties across all 3 groups may, again, reflect the high levels of social

disadvantage of the study sample (e.g., Buckingham et al., 2014; Dilnot et al., 2017).

The results also showed that, on a standardised test of basic motor skills (Movement

ABC-2), the children with severe EBD displayed significantly lower overall levels of

basic motor skill than the male and female comparison groups. Overall, 55% of the

children with severe EBD scored at or below the 5th percentile on total Movement

ABC-2 scores, which suggests clinically significant motor difficulties or probable

developmental coordination disorder (DCD) (Henderson et al., 2007). In contrast, 5%

and 2% of the male and female comparison groups, respectively, scored at or below

the 5th percentile on the MABC-2. These findings are in line with previous work on

motor skills in children who experience social, emotional and behavioural problems

(e.g., Ekornås et al., 2010; Hill et al., 2017; Iversen et al., 2006; Skirbekk et al.,

2012). However, previous studies have not included measures of social factors, such

as family-upset, so it is difficult to determine the contribution of broader ecological

factors to psychosocial outcomes in earlier work.

The results also showed that the children with severe EBD had significantly higher

levels of a persistent primary reflex, the asymmetric tonic neck reflex (ATNR),

relative to the comparison groups. This is the first study to explore the relationship

between early reflex persistence, an indicator of neurodevelopmental delay, and

psychosocial outcome. The high level of ATNR persistence in children with EBD

provides behavioural evidence of disturbance in an early subcortical system that has

been linked to a range of sub-optimal motor and cognitive outcomes (McPhillips &

Jordan-Black, 2007b; Morrison, 1985).

Regression model

The regression model accounted for 70% of the variance in total SDQ scores and

revealed that family upset, hyperactivity/impulsivity, literacy, basic motor skills and

ATNR persistence were all significant predictors of psychosocial outcome. Overall,

the results highlight how children with severe EBD are at risk of experiencing

significant, multiple co-occurring problems. In other words, motor difficulties may act

as a primary stressor on psychosocial outcome to some extent, as suggested by the

‘environmental stress hypothesis’ (Cairney et al., 2013), but the findings here also

suggest potentially complex, biopsychosocial inter-relationships. Further, the

measures of basic motor skills and reflex persistence used in this study acted as

separate, significant predictors of psychosocial outcome, in the context of other

significant predictors.

This is an important finding as it suggests that socio-emotional difficulties in children

with severe EBD may be related to neurological vulnerabilities involving early motor

and, in particular, vestibular system development. This is in line with previous

research that has highlighted the structural impact of mild family discord on a

subcortical structure, the cerebellum, in adolescents (Walsh et al., 2014). Further

research is required to unpick potential reciprocal relationships between early

adversity and motor vulnerability, including primary reflex persistence and the role of

the extensive projections of the vestibular system across multiple brain systems in

early development. Similarly, hyperactivity/impulsivity was the single largest

predictor of SDQ scores, and, given the association between hyperactivity/impulsivity

and motor difficulties in children with DCD (Kaiser et al., 2015), further work is

required to examine possible neurodevelopmental links between ADHD and early

motor functioning.

As mentioned earlier, there was evidence of a gender difference in SDQ scores

between the groups. These data, in association with the high levels of family-upset in

the severe EBD group and the preponderance of males with severe EBD, suggest

that male children may be more vulnerable to psychosocial problems when families

experience difficulties, assuming male and female children are at similar risk of

experiencing family-upset.

The cross-sectional design of the present study is a major limitation. Longitudinal

work is required to assess the relative importance of specific aspects of motor

function on psychosocial outcomes over time, and to examine the possible impact of

a wider range of adverse circumstances on the development of the different aspects

of motor function measured here. Family break-up was only one of the categories of

adversity used in the original ACEs research with adult samples (Boullier & Blair,

2018), and a more extensive measure of childhood adversity than that used in the

present study may have revealed even more powerful effects of adversity. A simple

index was used in this study as preliminary discussions with the school principal

revealed that there were potentially significant traumas in the lives of some of the

children with severe EBD. More in-depth family measures (e.g., in-depth interviews

or extensive questionnaires) were beyond the scope of the present study.

Conclusions

The results illustrate the importance of a broad biopsychosocial perspective in

understanding the diverse and complex problems experienced by children with

severe EBD. Addressing adverse environmental circumstances and enhancing

resilience may require comprehensive long-term societal and family support

strategies involving multi-agency provision. However, the findings also provide

strong evidence that children with severe EBD are at significant risk of motor

problems, including primary reflex persistence. From an educational perspective, the

findings suggest that specific approaches aimed at improving different aspects of

motor function in children with EBD should be incorporated into classroom practice

as a matter of urgency, with a particular emphasis on early intervention.

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Table 1 The means and standard deviations for group characteristics and dependent measures

Children with EBD

(EBD) n=29

Male comparison (MC) n=38

Female comparison (FC) n=45 F-values Post hoc

M SD M SD M SDAge (months)

WASI-2

SDQ

Conners 3

Inattention

Hyperactivity

WIAT-II

Literacy composite

Reading

Pseudowords

Spelling

Movement ABC-2

Total

Manual dexterity

Aiming & Catching

Balance

Adapted Schilder Test

Eyes Open

Eyes Closed

123.1

87.2

20.2

65.1

74.8

79.3

78.3

80.2

79.3

5.7

6.5

7.9

5.8

0.86

1.63

10.0

12.2

5.2

7.6

13.5

13.1

16.2

14.2

11.1

2.8

2.8

2.8

3.0

0.21

0.64

122.7

88.0

8.8

57.5

62.0

88.3

85.8

91.6

87.4

9.2

7.3

10.8

10.8

0.74

1.20

8.1

4.6

5.6

8.6

16.5

11.3

10.2

13.9

12.3

2.1

2.1

2.5

2.5

0.22

0.43

125.3

88.8

5.6

53.3

55.7

93.3

90.0

95.4

94.4

10.1

9.5

9.7

10.7

0.70

1.20

6.8

4.7

5.9

8.7

11.1

11.7

10.7

13.4

13.3

2.4

2.6

2.8

2.3

0.16

0.39

F(2,109) = 1.17, p = .315

F(2,109) = 0.41, p = .668

F(2,109) = 62.31, p < .001

F(2,109) = 17.56, p < .001

F(2,109) = 17.06 p < .001

F(2,109) = 12.24, p < .001

F(2,109) = 8.12, p = .001

F(2,109) = 11.08, p < .001

F(2,109) = 13.11, p < .001

F(2,109) = 29.55, p < .001

F(2,109) = 14.30, p < .001

F(2,109) = 9.35, p < .001

F(2,109) = 39.16, p < .001

F(2,109) = 6.43, p = .002

F(2,109) = 8.65, p < .001

EBD > (MC > FC)

EBD > (MC = FC)

EBD > (MC = FC)

EBD < (MC = FC)

EBD < (MC = FC)

EBD < (MC = FC)

(EBD < MC) < FC

EBD < (MC = FC)

(EBD = MC) < FC

EBD < (MC = FC)

EBD < (MC = FC)

EBD > (MC = FC)

EBD > (MC = FC)

32

MOTOR FUNCTION AND EBD 2

Table 2. Summary of hierarchical multiple regression model for variables predicting SDQ scores

b SE B β t R R2adj ∆R2

Step 1 .61 .37 .37

Constant 6.20 0.81 7.67***

Family-upset 9.98 1.24 .61 8.08***

Step 2 .77 .58 .22

Constant -12.98 3.37 -3.85***

Family-upset 5.51 1.20 .34 4.58***

Inattention 0.11 0.07 .13 1.55

Hyperactivity/Impulsivity 0.24 0.04 .45 5.70***

Step 3 .79 .61 .04

Constant 2.53 5.88 0.43

Family-upset 4.10 1.24 .25 3.32**

Inattention 0.07 0.07 .08 1.01

Hyperactivity/Impulsivity 0.23 0.04 .44 5.78***

Literacy -0.14 0.04 -.22 -3.16**

Step 4 .85 .70 .09

Constant 0.23 5.75 0.04

Family-upset 2.72 1.12 .17 2.44*

Inattention 0.04 0.06 .04 0.60

MOTOR FUNCTION AND EBD 3

Hyperactivity/Impulsivity 0.23 0.04 .44 6.51***

Literacy -0.10 0.04 -.17 -2.63*

Motor skills -0.42 0.16 -.16 -2.66**

ATNR persistence 4.04 0.90 .25 4.49***

Note. N = 112;*p <.05, **p <.01, ***p <.001

MOTOR FUNCTION AND EBD 4

0

Figure 1. A flow chart of the construction of the 3 groups

Severe EBD; n = 33

32 male, 1 female

Comparison sample; n = 192

87 male, 105 female

Severe EBD group

n = 29

Excluded males:

3 IQ < 70

1 diagnosis of Asperger Syndrome

4 incomplete data

41 IQ > 95

Excluded females:

1 IQ < 70

1 English not first language

2 incomplete data

56 IQ > 95

Male comparison

group

n = 38

Female comparison

group

n = 45

Excluded severe EBD:

1 female

3 males undergoing assessment

for ASD

MOTOR FUNCTION AND EBD 5

Figure 2. A boxplot of total and composite Movement ABC-2 standard scores according to group.

MOTOR FUNCTION AND EBD 6

Figure 3. A boxplot of arm:head movement ratios for the adapted Schilder test according to group.