Research in Developmental Disabilities 35 (2014) 1727–1733
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Research in Developmental Disabilities
High risk for obesity in children with a subtype of developmental coordination disorder Yi-Ching Zhu a, John Cairney b, Yao-Chuen Li b, Wei-Ying Chen c, Fu-Chen Chen d, Sheng K. Wu e,* a
Graduate Institute of Clinical Medical Science, China Medical University, Taichung City 404, Taiwan CanChild Centre for Childhood Disability Research, Departments of Family Medicine, Psychiatry & Behavioural Neurosciences & Kinesiology, McMaster University, Hamilton, ON, Canada c School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia d Department of Recreation Sport & Health Promotion, National Pingtung University of Science & Technology, Taiwan e Institute of Sport Performance, National Taiwan University of Physical Education & Sport, Taichung City 404, Taiwan b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 September 2013 Received in revised form 20 February 2014 Accepted 27 February 2014 Available online 27 March 2014
The purpose of this study was to compare the prevalence of overweight and obesity in typically developing (TD) children, children with developmental coordination disorder (DCD) and balance problems (DCD-BP), and children with DCD without balance problems (DCD-NBP). Two thousand and fifty-seven children (1095 boys, 962 girls) ages 9–12 years were recruited from 18 elementary schools in Taiwan. The Movement Assessment Battery for Children was used to assess motor coordination ability. International cut-off points for body mass index were used to classify participants into the following groups: normalweight, overweight or obese. Compared with TD children, children in the DCD-BP group were more than twice as likely to be obese (OR = 2.28; 95% CI = 1.41–3.68). DCD-BP children were also more likely to be obese compared to DCD-NBP children (OR = 1.79; 95% CI = 1.02–3.16). Boys in the DCD-BP group were more likely to be obese when compared to DCD-BP girls (OR = 3.12; 95% CI = 1.28–7.57). Similarly, DCD-NBP boys were more likely to be obese when compared to DCD-NBP girls (OR = 2.67; 95% CI = 1.21–5.89). Children with both DCD and BP were significantly more likely to be obese when compared to TD and DCD-NBP children. From an intervention perspective, the inclusion of regular physical activity, including activities that encourage development of both balance and energy expenditure, may be required to prevent obesity in this population. ß 2014 Elsevier Ltd. All rights reserved.
Keywords: Obesity Children Developmental coordination disorder Balance Taiwan
1. Introduction A diagnosis of developmental coordination disorder (DCD) is made when the level of performance of movement skills is substantially below that expected for a child’s chronological age and measured intelligence (American Psychiatric Association, 2000). The specific manifestations of the disorder affect both gross and fine motor skills. Children with DCD experience difficulties performing a wide variety of motor tasks, which results in significant negative impacts to everyday
* Corresponding author. Tel.: +886 4 22213108x2203; fax: +886 4 22250756. E-mail address: [email protected] (S.K. Wu). http://dx.doi.org/10.1016/j.ridd.2014.02.020 0891-4222/ß 2014 Elsevier Ltd. All rights reserved.
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activities of daily living, such as feeding, dressing, writing, self-care, and play skills (Barnhart, Davenport, Epps, & Nordquist, 2003; Missiuna, Moll, King, King, & Law, 2007). Even with practice/training, children with DCD have difficulties learning new skills and are likely to avoid participating in activities in order to prevent experiencing frustration and failure. Children with DCD are often less physically active and tend to prefer more sedentary lifestyle pursuits (Cairney, Kwan, Hay, & Faught, 2012; Wu, Lin, Li, Tsai, & Cairney, 2010). As a result, it has been argued that children with DCD are at increased risk of obesity and poor physical fitness, which in turn may lead to negative health outcomes later in life (Li, Wu, Cairney, & Hsieh, 2011). Currently, the precise causal connections between DCD and obesity are not yet known. Some studies report DCD as a risk factor for obesity, others stress the influence of weight on motor coordination/ability. For example, several studies have shown that children and adolescents with DCD were more likely to be overweight or obese compared to typically developing (TD) children, suggesting obesity may result from motor coordination difficulties (Cairney et al., 2010; Schott, Alof, Hultsch, & Meermann, 2007). Schott et al. (2007) in the UK study reported that the percentage of overweight and obese children ages 10–12 years was significantly higher in the DCD group than in the TD group. Cairney et al. (2010) using a large longitudinal sample of Canadian children found that those with DCD were at persistently greater risk of overweight (odds ration [OR] = 3.44) and obesity (OR = 4.00). At the same time, several studies have also shown that obesity may affect the motor proficiency of preschoolers and children. D’Hondt, Deforche, De Bourdeaudhuij, and Lenoir (2008) demonstrated that childhood overweight and obesity have a negative impact on fine motor skills performance when postural balance is simultaneously challenged. Some studies reported that overweight and obese children showed poorer locomotor skills, such as jumping, kicking and poor performance in the shuttle run and 30-m sprint when compared to their normal-weight peers (Graf et al., 2004; Okely, Booth, & Chey, 2004). Compared to balance ability, however, weight status in children may have less influence on object control and fine motor skills. Zhu, Li, and Wu (2010) reported that obesity was associated with poor performance on both static and dynamic balance tasks among boys and girls. Similarly, several studies also indicated that the higher risk for DCD in obese children in comparison to normal-weight peers was more pronounced in balance than in ball control and manual dexterity (D’Hondt et al., 2008; Wagner et al., 2011). Previous studies have investigated the balance ability of overweight and obese children and reported that these children displayed lower locomotor and balance skill levels compared with peers with healthy weight (Roberts, Veneri, Decker, & Gannotti, 2012). McGraw, McClenaghan, Williams, Dickerson, and Ward (2000) also found that obese prepubertal boys had poorer postural stability during quiet stance, and showed significantly greater sway, energy, and variability in the gait cycle. They suggested that the instability observed in obese boys may be caused by excess body weight. In addition, D’Hondt et al. (2011) demonstrated higher variability in postural sway velocity in overweight children. The above findings suggested that overweight or obesity may impose constraints on children’s balance and functional performance. It is well known that DCD is a highly heterogeneous disorder, and children frequently present with co-occurring conditions in addition to their motor difficulties (Macnab, Miller, & Polatajko, 2001; Visser, 2003). Clearly, there are no typical motor deficit profiles of children with DCD. Children with DCD have been found to show several subtypes (Hoare, 1994; Zhu et al., 2010). The construct of ‘‘subtype’’ was proposed in order to understand the nature and characteristics of children with DCD in greater depth. There are two methods used to classify different subtypes of DCD in the extant literature. The first approach is descriptive: The researcher selects specific cutoff points on different sub-tests (e.g., tests of balance; tests of fine motor skills) used to assess DCD to classify children into different subgroups (Hoare, 1994; Macnab et al., 2001). For example, Geuze (2003) and Tsai, Wu and Huang (2008) created a subtype children with DCD and balance problems (DCDBP) using the following criteria: Total Impairment Score (TIS) of the Movement Assessment Battery for Children test (MABC test) at or below 5th percentile; the Total Balance Score (TBS) of the MABC test at or below 5th percentile; and the static balance score >1 on the MABC test. The second classification method for children with DCD is based on a statistical approach - cluster analysis. However, because the initial selection of variables to include in the cluster analysis is left to the discretion of the researchers involved, this inevitably leads to different subtype classifications (Hoare, 1994; Macnab et al., 2001; Wu, Lin, & Zhu, 2007; Zhu et al., 2010). In general, the results of this work have led to subtypes characterized by a generalized motor deficit or by difficulties in particular fundamental or functional abilities, such as balance ability, fine motor skills and ball control (Wright & Sugden, 1996; Wu et al., 2007; Zhu et al., 2010). Because the present study focuses specifically on the role of balance problems in relation to overweight and obesity in children with and without DCD, the descriptive approach was selected to classify DCD subtype groups. A subtype of children with DCD-BP has been consistently identified in most subtyping studies (Hoare, 1994; Macnab et al., 2001; Wu et al., 2007; Zhu et al., 2010). Previous studies have shown that children with DCD-BP had a marked sway in the center of pressure, either during the two-leg stance or in more difficult conditions like standing on the non-preferred leg with eyes closed (Geuze, 2003; Tsai, Wu, & Huang, 2008). Although previous studies have reported that obesity may be associated with poor motor coordination ability, particularly in relation to balance ability, these studies have been somewhat limited by small samples; this in turn affects the ability to make statistical comparisons within and between subtype groups of children with DCD. Therefore, the purpose of the present study was to compare the prevalence of overweight and obesity among TD children, children with DCD and balance problems (DCD-BP), and children with DCD and no balance problems (DCD-NBP). We hypothesized that the prevalence of overweight and obesity would be higher in the DCD-BP subtype group. When compared to those in the DCD-NBP and TD groups. Because there is inconsistency in the results concerning the relationship between balance and obesity between boys and girls in the published literature (Cairney et al., 2010; Graf et al., 2004; Wagner et al., 2011), gender differences were also examined.
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2. Methods 2.1. Participants We recruited 18 elementary schools around Taiwan and randomly selected four classes in Grades 3–6 from each school. Parents or guardians of the children aged 9–12 years received a letter with information regarding the purpose and procedures of this study and signed the informed consent before the children participated in this study. A total of 2057 children (1095 boys and 962 girls) agreed to participate in this study. Children with medical conditions that affect motor ability (e.g., cerebral palsy, muscular dystrophy or any physical impairment) or intellectual disabilities were excluded from this study. This study included participants with DCD-BP (N = 178), DCD-NBP (N = 329) and TD (N = 1087), excluding borderline DCD (N = 463) for analysis. This study was approved by the Ethical Committee of the National Taiwan University of Physical Education and Sport and was supported by the National Science Council in Taiwan. 2.2. Assessments 2.2.1. Subtypes of developmental coordination disorder (DCD) The Movement Assessment Battery for Children test (MABC test) (Henderson & Sugden, 1992) was used to screen participants. The MABC consists of eight age-specific testing items and has three subscales that measure manual dexterity, ball skills, and static and dynamic balance. The Movement ABC test was administered by trained research assistants. After the assessment, the raw score of each item is converted into a scaled score ranging from 0 and 5 according to the test manual (Henderson & Sugden, 1992). The sum of these testing scores provides a Total Impairment Scores (TIS), with a lower scores representing better motor coordination ability. When the TIS of a child is greater than 13.5, according to the norm of the MABC test, he or she was classified as having DCD. When the TIS score is between 10 and 13.5, a child was defined as borderline DCD. When the TIS score was less than 10, a child was defined as typically developing (Henderson & Sugden, 1992). In this study, data from children with borderline DCD were not included for further analysis and comparison. The MABC test has been shown to have good reliability and concurrent validity (Chow & Henderson, 2003; Croce, Horvat, & McCarthy, 2001), and is widely accepted internationally as a measure for assessing DCD (Henderson & Sugden, 1992) including Taiwan (Wu et al., 2010; Zhu, Wu, & Cairney, 2011). As noted previously, the descriptive approach was selected to classify subtypes of DCD-BP and DCD-NBP in the present study. Although previous studies have used a total balance score (TBS) at or below the 5th percentile as a cutoff for classifying children with DCD and BP (Geuze, 2003; Tsai et al., 2008), we selected a broader classification (cutoff at or below the 15th percentile on the TBS), identifying children both at risk for having balance problems, and those with balance problems (N = 2057). Part of the rationale for this is based on the previous literature which shows that children scoring at or below the 15th percentile on the M-ABC to be at greater risk for overweight and obesity, when compared to TD children (Cairney, Hay, Veldhuizen, & Faught, 2011). The 15th percentile cut-off for the TBS is a score of 6.5. The selection criteria for children with DCD-BP were TIS score 13.5 and TBS score >6.5. The selection criteria for the children with DCD-NBP were TIS score 13.5 and TBS score 6.5. 2.2.2. Anthropometry Trained research assistants measured body height of participants according to standard procedures. Body height was determined to the nearest 0.1 cm using a portable, medical stadiometer. Body weight (kg) was assessed using an electric scale (TBF-521, TANITA, Tokyo, Japan) and waist and hip circumferences were measured using a tape measurement. Body weight and height measurements were used to calculate body mass index (BMI) (kg/m2) for each participant. We used BMI to identify overweight and obesity because of its safety, practical advantages and strong correlation with direct adiposity measures derived from dual energy X-ray absorptiometry (Foo, Teo, Abdullah, Aziz, & Hills, 2013). In this study, the International Obesity Task Force (IOTF) reference was used to define overweight and obesity in children (Cole, Bellizzi, Flegal, & Dietz, 2000). The IOTF reference including age and gender specific cut-offs is used for children 2–18 years of age. The IOTF reference has been recognized as one of the most definitive sources for normative data to define overweight or obesity in the world, because it was developed from a database of 97,876 boys and 94,851 girls from birth to 25 years of age from six countries (i.e., Brazil, Great Britain, Hong Kong, Netherlands, Singapore, and USA). IOTF reference percentile curves were constructed using an LMS method, and BMI values of 25 and 30 at 18 years of age for boys and girls were tracked back to define BMI values for overweight and obesity at younger ages. According to Cole et al. (2000), the definition of overweight and obesity derived from their data are less arbitrary and more international than other data, allowing researchers, policy makers, or practitioners to make direct comparisons of the prevalence of pediatric obesity around the world. 2.3. Statistical analysis Statistical analyses were carried out using the SPSS version 17.0 for Windows (SPSS Inc., Chicago, IL). The descriptive statistics for the anthropometric data and motor coordination ability are provided. A two-way analysis of variance (ANOVA)
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Table 1 Difference in anthropometric characteristics and motor coordination ability between TD, DCD-BP and DCD-NBP children. DCD-BP
TD
Demographic data Age (year)a Height (cm)a,c Weight (kg)a,b BMI (kg/m2)a,b Waist circumference Hip circumferencea WHRa,b
a,b
MABC scores Manual dexteritya,b,c Ball skillsa,b,c Total balance scorea Total impairment scorea,c
DCD-NBP
Group post hoc
Boys (N = 631)
Girls (N = 456)
Boys (N = 85)
Girls (N = 93)
Boys (N = 143)
Girls (N = 186)
10.57 1.11 145.79 10.36 41.48 11.90 19.22 3.71 65.71 13.20 77.83 13.51 0.84 0.06
10.47 1.11 144.97 9.62 38.21 9.91 17.96 3.17 62.22 12.16 77.04 13.47 0.81 0.06
11.08 0.79 147.39 9.51 47.87 12.93 21.76 4.33 72.79 14.63 83.16 13.74 0.87 0.07
11.27 0.81 150.82 8.65 45.60 11.55 19.90 4.12 67.95 12.48 82.99 13.75 0.82 0.06
10.20 0.97 142.42 10.13 40.73 13.47 19.65 4.36 67.15 13.99 77.70 13.81 0.86 0.06
10.10 0.86 141.79 8.97 36.88 8.95 18.12 2.94 61.71 13.49 74.51 14.64 0.83 0.07
BP > TD > NBP BP > TD > NBP BP > TD, NBP BP > TD, NBP BP > TD, NBP BP > TD, NBP BP, NBP > TD
6.78 3.13 3.95 2.91 8.68 1.95 19.42 5.48
4.13 2.91 5.32 2.55 8.85 1.81 18.30 3.69
7.99 2.58 4.20 2.51 4.19 1.46 16.38 2.61
6.28 2.54 6.18 2.46 3.69 1.51 16.15 2.50
NBP > BP > TD NBP > BP > TD BP > NBP > TD BP > NBP > TD
2.29 2.01 0.79 1.19 2.56 1.98 5.64 2.44
2.06 2.01 1.66 1.78 2.33 2.01 6.06 2.40
Note. BMI: body mass index; WHR: waist to hip ratio; BP: DCD-BP; NBP: DCD-NBP. a Main effects of groups, p < .001. b Main effects of genders, p < .001 c Interaction effects of group gender, p < .05.
with Scheffe’s post hoc was conducted to examine the main effects of group, gender, and the group gender interactions. We selected the Scheffe’s test because it is the most conservative with respect to Type I error (Hair, Black, Babin, Anderson, & Tatham, 2006). A Pearson Chi-Square analysis was used to compare the prevalence of overweight and obese children across the DCD-BP, DCD-NBP, and TD groups. Odds ratio (OR) with 95% confidence intervals (CI) was calculated to estimate obesity risk. A p-value less than 0.05 was set as the minimum threshold for statistical significance. 3. Results The main effect for group was significant for the anthropometric characteristics and MABC scores (Table 1). Most of the anthropometric data (e.g., weight; waist circumference) were higher in the DCD-BP group compared with the other two groups. Children in the DCD-NBP had higher subscale scores (higher scores indicate greater impairments) in manual dexterity and ball skills than those of the DCD-BP and TD groups. The total balance scores and total impairment score were significantly higher in the DCD-BP group, when compared to the DCD-NBP and TD groups. The main effect of gender was also significant for manual dexterity and ball skills: Girls had higher scores than boys in the manual dexterity domain; boys had higher scores than girls in the ball skills domain. There was also a significant interaction effect between gender and group for manual dexterity, ball skills, and total impairment scores (Table 1). Table 2 shows the prevalence of obesity, overweight and normal weight in the TD, DCD-BP and DCD-NBP groups respectively. Prevalence was highest in the DCD-BP group (15.2%), compared to the DCD-NBP (9.1%) and TD groups (7.5%) (x2 = 12.37, df = 4, p < .05). Although the prevalence of overweight was higher in the DCD-BP and DCD-NBP groups than those in the TD group, these differences were not statistically significant (x2 = 1.14, df = 2, p > .05). Compared with TD children, children in the DCD-BP group were more than twice as likely to be obese (OR = 2.28; 95% CI = 1.41–3.68; p < .01). DCD-BP children were also more likely to be obese compared to DCD-NBP children (OR = 1.79; 95% CI = 1.02–3.16; p < .05). Table 3 shows the prevalence of normal weight, overweight and obesity in TD, DCD-BP and DCD-NBP for boys and girls separately. Compared with TD girls, TD boys were more likely to be overweight (OR = 1.59; 95% CI = 1.17–2.12; p < .05) and obese (OR = 2.31; 95% CI = 1.39–3.84; p < .05). Similarly, DCD-BP boys were more than twice as likely to be overweight (OR = 2.20; 95% CI = 1.06–4.56; p < .05) and three times more likely to be obese (OR = 3.12; 95% CI = 1.28–7.57; p < .05) when compared to DCD-BP girls. DCD-NBP boys were also more likely to be obese when compared to DCD-NBP girls (OR = 2.67; 95% CI = 1.21–5.89; p < .05). Although the prevalence of overweight was higher in DCD-NBP boys when compared to DCDNBP girls, the difference was not statistically significant (x2 = 1.64, df = 1, p > .05).
Table 2 Prevalence of normal weight, overweight and obesity among three groups.
Normal-weight Overweight Obese
TD (N = 1087)
DCD-BP (N = 178)
DCD-NBP (N = 329)
761 (70.0%) 244 (22.4%) 82 (7.5%)
110 (61.8%) 41 (23.0%) 27 (15.2%)
219 (66.6%) 80 (24.3%) 30 (9.1%)
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Table 3 Prevalence of normal weight, overweight and obesity in TD, DCD-BP and DCD-NBP boys and girls. DCD-BP
TD
Normal-weight Overweight Obese
DCD-NBP
Girl (N = 456)
Boy (N = 631)
Girl (N = 93)
Boy (N = 85)
Girl (N = 186)
Boy (N = 143)
349 (76.5%) 85 (18.6%) 22 (4.8%)
412 (65.3%) 159 (25.2%) 60 (9.5%)
67 (72.0%) 17 (18.3%) 9 (9.7%)
43 (50.6%) 24 (28.2%) 18 (21.2%)
133 (71.5%) 42 (22.6%) 11 (5.9%)
86 (60.1%) 38 (26.6%) 19 (13.3%)
4. Discussion This study investigated the prevalence of overweight and obesity on two subtypes of children with DCD: Those with and without balance problems. We hypothesized that the prevalence of overweight and obesity would be higher in the DCD-BP subtype than those in the DCD-NBP and TD groups. Our hypothesis is supported by the findings that children with a subtype of DCD-BP have a higher obese risk in comparison to children with DCD-NBP and TD. It is often observed that many children with DCD demonstrate an awkward running pattern, fall frequently, and have a difficulty in imitating body positions. Because of their motor problems, including poor balance control, children with DCD perform poorly in sporting events such as track and field and ball activities. Overtime these children may become frustrated and avoid participating in sports activities altogether. Reduced time spent in physical activities further retards the development of movement skills and finally may result in decreased physical fitness and health conditions (Schott et al., 2007). Many empirical studies have confirmed that children with DCD have lower levels in physical activities and fitness compared to their peers (Rivilis et al., 2011; Wu et al., 2010). Low physical fitness is moderately to highly associated with a higher risk of obesity and several empirical studies have demonstrated that children with DCD were more likely to be overweight or obese compared to TD children (Cairney et al., 2010; Schott et al., 2007; Zhu et al., 2011). Physical activity is defined as any bodily movement produced by skeletal muscles that require energy expenditure. Most physical activities using large muscle groups such as walking, running, jumping, cycling, or participating in sports, require adequate balance abilities. This may be one of the reasons that DCD-BP children were more likely to be obese compared to DCD-NBP and TD children. In this study, however, we could not compare physical activities among children with DCD-BP, DCD-NBP and TD. A causal link between balance ability, physical activities and weight status cannot therefore be determined empirically. Hence, this crucial notion needs to be confirmed by direct examinations and further evidence. However, other explanations for a link between DCD, balance problems and obesity need to also be considered. Various studies have suggested that excessive increases in weight bearing forces caused by obesity may have a negative effect on the feet (D’Hondt et al., 2011; Dowling, Steele, & Baur, 2001; Riddiford-Harland, Steele, & Baur, 2011). Due to the continuous increased loading on the feet as a result of the excess body weight, childhood overweight and obesity may cause actual changes in foot structure. Overweight or obese children displayed significantly lower plantar arch height, larger foot dimensions, larger contact areas with the ground, and increased plantar pressure values than their non-obese counterparts (Dowling et al., 2001; Riddiford-Harland et al., 2011). These structural differences may reduce the quality and quantity of the sensory information from the mechanoreceptors within the plantar surface, which could contribute to the maintenance of postural stability (Hue et al., 2007). Furthermore, obesity affects the speed and kinematics of gait, static and dynamic balance in children, which may influence skill acquisitions (Colne, Frelut, Peres, & Thoumie, 2008). Recently, Castetbon and Andreyeva (2012) and Roberts et al. (2012) also found that balance skills involving hopping, jumping and backwards walking were more difficult for obese children compared with their peers who were not obese. Such locomotor competences are likely to be directly related to the excess weight and impaired musculoskeletal functions of obese children (Castetbon & Andreyeva, 2012). In addition, several studies have reported that overweight and obesity affects gross motor skills, not manipulative motor task and fine motor skills in young children (Castetbon & Andreyeva, 2012; Roberts et al., 2012; Wagner et al., 2011; Zhu et al., 2011). Our findings are similar to those recent studies that have indicated DCD-BP children were more likely to be obese compared to DCD-NBP children (OR = 1.79). Our findings were consistent with results shown in a previous study that boys had a higher obese risk compared to girls among DCD-BP and DCD-NBP groups (Wagner et al., 2011). In contrast with previous research suggesting the existence of no gender differences (Cairney et al., 2010; Graf et al., 2004), our results are consistent with research showing increased risk of obesity in children with DCD is specific to boys only (Cairney et al., 2012). The gender difference in motor performance may reflect different sociocultural influences on boys and girls (Cairney et al., 2010, 2012; Graf et al., 2004; Zhu, Li, & Wu, 2008). In Taiwan, particularly, boys with or without DCD were more obese and overweight than girls (Zhu et al., 2011). On the other hand, we also found gender differences in the kinds of activities which children were willing to and able to participate in: Boys tended to choose ball activities and expressed a desire to be good at such activities (Zhu et al., 2008). Girls, conversely, appear to be interested in activities that encourage the development of static and dynamic balance (Mickle, Munro, & Steele, 2011; Wagner et al., 2011). The strength of our present study includes the large sample size, which allowed us to make statistical comparisons within and between groups on the basis of both gender and DCD-subtype simultaneously. To our knowledge, this is the first
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empirical study that has examined the risk of obesity in children, across different subtypes of DCD. Nevertheless, a number of limitations still need to be considered. The current study did not include any measures of physical activity, lifestyle and physical fitness, and hence the assumption of a mediated impact remains hypothetical. This is a cross-sectional design and so a causal relationship between other influencing variables can only be hypothesized. Future research using a longitudinal, cohort design is required to establish causality. 5. Conclusion and implications This study identified that a subtype of children with DCD and balance problem were at significantly increased risk for obesity compared to typically developing children and children with DCD and no balance problem. We may expect that obese or overweight children with DCD and balance problem may also have poorer physical fitness and health compared to other children. These findings suggest that the inclusion of regular physical activity, particularly in relation to balance activities, may be important for the prevention of obesity or overweight in children. In the future, more longitudinal studies monitoring changes between obesity, physical activity, fitness, and motor coordination ability in different ages and genders of children and adolescents are urgently needed. Acknowledgements This study was supported by National Science Council in Taiwan (NSC98-2410-H-028-006 & 100-2314-B-028-001). We were greatly appreciative of the participation of children, parents and school staff in this study. Dr. Cairney is supported by an endowed professorship in child health through the Department of Family Medicine at McMaster University. References American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th text revision ed.). Washington, DC: Author. Barnhart, R. C., Davenport, M. J., Epps, S. B., & Nordquist, V. M. (2003). Developmental coordination disorder. Physical Therapy, 83(8), 722–731. Cairney, J., Hay, J., Veldhuizen, S., & Faught, B. E. (2011). Assessment of body composition using whole body air-displacement plethysmography in children with and without developmental coordination disorder. Research in Developmental Disabilities, 32, 830–835. http://dx.doi.org/10.1016/j.ridd.2010.10.011 Cairney, J., Hay, J. A., Veldhuizen, S., Missiuna, C., Mahlberg, N., & Faught, B. E. (2010). Trajectories of relative weight and waist circumference among children with and without developmental coordination disorder. Canadian Medical Association Journal, 182, 1167–1172. http://dx.doi.org/10.1503/cmaj.091454 Cairney, J., Kwan, M. Y., Hay, J. A., & Faught, B. E. (2012). Developmental coordination disorder, gender, and body weight: Examining the impact of participation in active play. Research in Developmental Disabilities, 33, 1566–1573. http://dx.doi.org/10.1016/j.ridd.2012.02.026 Castetbon, K., & Andreyeva, T. (2012). Obesity and motor skills among 4 to 6-year-old children in the United States: Nationally-representative surveys. BMC Pediatrics, 12, 28. http://dx.doi.org/10.1186/1471-2431-12-28 Chow, S. M. K., & Henderson, S. E. (2003). Interrater and test–retest reliability of the Movement Assessment Battery for Chinese preschool children. American Journal of Occupational Therapy, 57, 574–577. Cole, T. J., Bellizzi, M. C., Flegal, K. M., & Dietz, W. H. (2000). Establishing a standard definition for child overweight and obesity worldwide: International survey. British Medical Journal, 320, 1–6. http://dx.doi.org/10.1136/bmj.320.7244.1240 Colne, P., Frelut, M. L., Peres, G., & Thoumie, P. (2008). Postural control in obese adolescents assessed by limits of stability and gait initiation. Gait & Posture, 28, 164–169. http://dx.doi.org/10.1016/j.gaitpost.2007.11.006 Croce, R. V., Horvat, M., & McCarthy, E. (2001). Reliability and concurrent validity of the Movement Assessment Battery for Children. Perceptual and Motor Skills, 93, 275–280. D’Hondt, E., Deforche, B., De Bourdeaudhuij, I., Gentier, I., Tanghe, A., Shultz, S., et al. (2011). Postural balance under normal and altered sensory conditions in normal-weight and overweight children. Clinical Biomechanics, 26, 84–89. http://dx.doi.org/10.1016/j.clinbiomech.2010.08.007 D’Hondt, E., Deforche, B., De Bourdeaudhuij, I., & Lenoir, M. (2008). Childhood obesity affects fine motor skill performance under different postural constraints. Neuroscience Letters, 440, 72–75. http://dx.doi.org/10.1016/j.neulet.2008.05.056 Dowling, A. M., Steele, J. R., & Baur, L. A. (2001). Does obesity influence foot structure and plantar pressure patterns in prepubescent children? International Journal of Obesity, 25, 845–852. Foo, L. H., Teo, P. S., Abdullah, N. F., Aziz, M. E., & Hills, A. P. (2013). Relationship between anthropometric and dual energy X-ray absorptiometry measures to assess total and regional adiposity in Malaysian adolescents. Asia Pacific Journal Clinical Nutrition, 22, 348–356. Graf, C., Koch, B., Kretschmann-Kandel, E., Falkowski, G., Christ, H., Coburger, S., et al. (2004). Correlation between BMI, leisure habits and motor abilities in childhood (CHILT-project). International Journal of Obesity, 28, 22–26. http://dx.doi.org/10.1038/sj.ijo.0802428 Geuze, R. H. (2003). Static balance and developmental coordination disorder. Human Movement Science, 22, 527–548. http://dx.doi.org/10.1155/NP.2005.183 Hair, J. F., Black, W. C., Babin, B. J., Anderson, R. E., & Tatham, R. L. (2006). Multivariate data analysis (6th ed., pp. 424–). New Jersey: Pearson Prentice Hall. Henderson, S. E., & Sugden, D. A. (1992). Movement assessment battery for children (1st ed.). London: The Psychological Corporation. Hoare, D. (1994). Subtypes of developmental coordination disorder. Adapted Physical Activity Quarterly, 11, 158–169. Hue, O., Simoneau, M., Marcotte, J., Berrigan, F., Dore´, J., Marceau, P., et al. (2007). Body weight is a strong predictor of postural stability. Gait & Posture, 26, 32–38. http://dx.doi.org/10.1186/1743-0003-8-20 Li, Y. C., Wu, S. K., Cairney, J., & Hsieh, C. Y. (2011). Motor coordination and health-related physical fitness of children with developmental coordination disorder: A three-year follow-up study. Research in Developmental Disabilities, 32, 2993–3002. http://dx.doi.org/10.1016/j.ridd.2011.04.009 Macnab, J. J., Miller, L. T., & Polatajko, H. J. (2001). The search for subtypes of DCD: Is cluster analysis the answer? Human Movement Science, 20, 49–72. http:// dx.doi.org/10.1016/S0167-9457(01)00028-8 McGraw, B., McClenaghan, B. A., Williams, H. G., Dickerson, J., & Ward, D. S. (2000). Gait and postural stability in obese and nonobese prepubertal boys. Archives of Physical Medicine and Rehabilitation, 81, 484–489. http://dx.doi.org/10.1053/mr.2000.3782 Mickle, K. J., Munro, B. J., & Steele, J. R. (2011). Gender and age affect balance performance in primary school-aged children. Journal of Science and Medicine in Sport, 14, 243–248. http://dx.doi.org/10.1016/j.jsams.2010.11.002 Missiuna, C., Moll, S., King, S., King, G., & Law, M. (2007). A trajectory of troubles: Parents’ impressions of the impact of developmental coordination disorder. Physical & Occupational Therapy in Pediatrics, 27(1), 81–101. Okely, A. D., Booth, M. L., & Chey, T. (2004). Relationships between body composition and fundamental movement skills among children and adolescents. Research Quarterly for Exercise and Sport, 75, 238–247. http://dx.doi.org/10.1080/02701367.2004.10609157 Riddiford-Harland, D. L., Steele, J. R., & Baur, L. A. (2011). Are the feet of obese children fat or flat? Revisiting the debate. International Journal of Obesity, 35, 115–120. http://dx.doi.org/10.1038/ijo.2010.119
Y.-C. Zhu et al. / Research in Developmental Disabilities 35 (2014) 1727–1733
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Rivilis, I., Hay, J., Cairney, J., Klentrou, P., Liu, J., & Faught, B. E. (2011). Physical activity and fitness in children with developmental coordination disorder: A systematic review. Research in Developmental Disabilities, 32, 894–910. http://dx.doi.org/10.1016/j.ridd.2011.01.017 Roberts, D., Veneri, D., Decker, R., & Gannotti, M. (2012). Weight status and gross motor skill in kindergarten children. Pediatric Physical Therapy, 24, 353–360. http://dx.doi.org/10.1097/PEP.0b013e3182680f19 Schott, N., Alof, V., Hultsch, D., & Meermann, D. (2007). Physical fitness in children with developmental coordination disorder. Research Quarterly for Exercise and Sport, 78, 438–450. http://dx.doi.org/10.1080/02701367.2007.10599444 Tsai, C. L., Wu, S. K., & Huang, C. H. (2008). Static balance in children with developmental coordination disorder. Human Movement Science, 27, 142–153. http:// dx.doi.org/10.1016/j.humov.2007.08.002 Visser, J. (2003). Developmental coordination disorder: A review of research on subtypes and comorbidities. Human Movement Science, 22, 479–493. http:// dx.doi.org/10.1016/j.humov.2003.09.005 Wagner, M. O., Kastner, J., Petermann, F., Jekauc, D., Worth, A., & Bo¨s, K. (2011). The impact of obesity on developmental coordination disorder in adolescence. Research in Developmental Disabilities, 32, 1970–1976. http://dx.doi.org/10.1016/j.ridd.2011.04.004 Wright, H. C., & Sugden, D. A. (1996). The nature of developmental coordination disorder: Inter- and intragroup differences. Adapted Physical Activity Quarterly, 13, 357–371. Wu, S. K., Lin, H. H., Li, Y. C., Tsai, C. L., & Cairney, J. (2010). Cardiopulmonary fitness and endurance in children with developmental coordination disorder. Research in Developmental Disabilities, 31, 345–349. http://dx.doi.org/10.1016/j.ridd.2009.09.018 Wu, S. K., Lin, K. H., & Zhu, Y. C. (2007). Analysis of subgroups of children with developmental coordination disorder based on Movement ABC test. Health Promotion Science, 2, 95–105. Zhu, Y. C., Li, Y. C., & Wu, S. K. (2008). Changes of motor coordination ability in 9 and 10 year-old children in Taiwan. Health Promotion Science, 3, 11–22. Zhu, Y. C., Li, Y. C., & Wu, S. K. (2010). Subtypes of children with developmental coordination disorder in Taiwan. Formosan Journal of Physical Therapy, 35, 243–250. Zhu, Y. C., Wu, S. K., & Cairney, J. (2011). Obesity and motor coordination ability in Taiwanese children with and without developmental coordination disorder. Research in Developmental Disabilities, 32, 801–807. http://dx.doi.org/10.1016/j.ridd.2010.10.020
Contents lists available at ScienceDirect
Research in Developmental Disabilities
High risk for obesity in children with a subtype of developmental coordination disorder Yi-Ching Zhu a, John Cairney b, Yao-Chuen Li b, Wei-Ying Chen c, Fu-Chen Chen d, Sheng K. Wu e,* a
Graduate Institute of Clinical Medical Science, China Medical University, Taichung City 404, Taiwan CanChild Centre for Childhood Disability Research, Departments of Family Medicine, Psychiatry & Behavioural Neurosciences & Kinesiology, McMaster University, Hamilton, ON, Canada c School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia d Department of Recreation Sport & Health Promotion, National Pingtung University of Science & Technology, Taiwan e Institute of Sport Performance, National Taiwan University of Physical Education & Sport, Taichung City 404, Taiwan b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 September 2013 Received in revised form 20 February 2014 Accepted 27 February 2014 Available online 27 March 2014
The purpose of this study was to compare the prevalence of overweight and obesity in typically developing (TD) children, children with developmental coordination disorder (DCD) and balance problems (DCD-BP), and children with DCD without balance problems (DCD-NBP). Two thousand and fifty-seven children (1095 boys, 962 girls) ages 9–12 years were recruited from 18 elementary schools in Taiwan. The Movement Assessment Battery for Children was used to assess motor coordination ability. International cut-off points for body mass index were used to classify participants into the following groups: normalweight, overweight or obese. Compared with TD children, children in the DCD-BP group were more than twice as likely to be obese (OR = 2.28; 95% CI = 1.41–3.68). DCD-BP children were also more likely to be obese compared to DCD-NBP children (OR = 1.79; 95% CI = 1.02–3.16). Boys in the DCD-BP group were more likely to be obese when compared to DCD-BP girls (OR = 3.12; 95% CI = 1.28–7.57). Similarly, DCD-NBP boys were more likely to be obese when compared to DCD-NBP girls (OR = 2.67; 95% CI = 1.21–5.89). Children with both DCD and BP were significantly more likely to be obese when compared to TD and DCD-NBP children. From an intervention perspective, the inclusion of regular physical activity, including activities that encourage development of both balance and energy expenditure, may be required to prevent obesity in this population. ß 2014 Elsevier Ltd. All rights reserved.
Keywords: Obesity Children Developmental coordination disorder Balance Taiwan
1. Introduction A diagnosis of developmental coordination disorder (DCD) is made when the level of performance of movement skills is substantially below that expected for a child’s chronological age and measured intelligence (American Psychiatric Association, 2000). The specific manifestations of the disorder affect both gross and fine motor skills. Children with DCD experience difficulties performing a wide variety of motor tasks, which results in significant negative impacts to everyday
* Corresponding author. Tel.: +886 4 22213108x2203; fax: +886 4 22250756. E-mail address: [email protected] (S.K. Wu). http://dx.doi.org/10.1016/j.ridd.2014.02.020 0891-4222/ß 2014 Elsevier Ltd. All rights reserved.
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activities of daily living, such as feeding, dressing, writing, self-care, and play skills (Barnhart, Davenport, Epps, & Nordquist, 2003; Missiuna, Moll, King, King, & Law, 2007). Even with practice/training, children with DCD have difficulties learning new skills and are likely to avoid participating in activities in order to prevent experiencing frustration and failure. Children with DCD are often less physically active and tend to prefer more sedentary lifestyle pursuits (Cairney, Kwan, Hay, & Faught, 2012; Wu, Lin, Li, Tsai, & Cairney, 2010). As a result, it has been argued that children with DCD are at increased risk of obesity and poor physical fitness, which in turn may lead to negative health outcomes later in life (Li, Wu, Cairney, & Hsieh, 2011). Currently, the precise causal connections between DCD and obesity are not yet known. Some studies report DCD as a risk factor for obesity, others stress the influence of weight on motor coordination/ability. For example, several studies have shown that children and adolescents with DCD were more likely to be overweight or obese compared to typically developing (TD) children, suggesting obesity may result from motor coordination difficulties (Cairney et al., 2010; Schott, Alof, Hultsch, & Meermann, 2007). Schott et al. (2007) in the UK study reported that the percentage of overweight and obese children ages 10–12 years was significantly higher in the DCD group than in the TD group. Cairney et al. (2010) using a large longitudinal sample of Canadian children found that those with DCD were at persistently greater risk of overweight (odds ration [OR] = 3.44) and obesity (OR = 4.00). At the same time, several studies have also shown that obesity may affect the motor proficiency of preschoolers and children. D’Hondt, Deforche, De Bourdeaudhuij, and Lenoir (2008) demonstrated that childhood overweight and obesity have a negative impact on fine motor skills performance when postural balance is simultaneously challenged. Some studies reported that overweight and obese children showed poorer locomotor skills, such as jumping, kicking and poor performance in the shuttle run and 30-m sprint when compared to their normal-weight peers (Graf et al., 2004; Okely, Booth, & Chey, 2004). Compared to balance ability, however, weight status in children may have less influence on object control and fine motor skills. Zhu, Li, and Wu (2010) reported that obesity was associated with poor performance on both static and dynamic balance tasks among boys and girls. Similarly, several studies also indicated that the higher risk for DCD in obese children in comparison to normal-weight peers was more pronounced in balance than in ball control and manual dexterity (D’Hondt et al., 2008; Wagner et al., 2011). Previous studies have investigated the balance ability of overweight and obese children and reported that these children displayed lower locomotor and balance skill levels compared with peers with healthy weight (Roberts, Veneri, Decker, & Gannotti, 2012). McGraw, McClenaghan, Williams, Dickerson, and Ward (2000) also found that obese prepubertal boys had poorer postural stability during quiet stance, and showed significantly greater sway, energy, and variability in the gait cycle. They suggested that the instability observed in obese boys may be caused by excess body weight. In addition, D’Hondt et al. (2011) demonstrated higher variability in postural sway velocity in overweight children. The above findings suggested that overweight or obesity may impose constraints on children’s balance and functional performance. It is well known that DCD is a highly heterogeneous disorder, and children frequently present with co-occurring conditions in addition to their motor difficulties (Macnab, Miller, & Polatajko, 2001; Visser, 2003). Clearly, there are no typical motor deficit profiles of children with DCD. Children with DCD have been found to show several subtypes (Hoare, 1994; Zhu et al., 2010). The construct of ‘‘subtype’’ was proposed in order to understand the nature and characteristics of children with DCD in greater depth. There are two methods used to classify different subtypes of DCD in the extant literature. The first approach is descriptive: The researcher selects specific cutoff points on different sub-tests (e.g., tests of balance; tests of fine motor skills) used to assess DCD to classify children into different subgroups (Hoare, 1994; Macnab et al., 2001). For example, Geuze (2003) and Tsai, Wu and Huang (2008) created a subtype children with DCD and balance problems (DCDBP) using the following criteria: Total Impairment Score (TIS) of the Movement Assessment Battery for Children test (MABC test) at or below 5th percentile; the Total Balance Score (TBS) of the MABC test at or below 5th percentile; and the static balance score >1 on the MABC test. The second classification method for children with DCD is based on a statistical approach - cluster analysis. However, because the initial selection of variables to include in the cluster analysis is left to the discretion of the researchers involved, this inevitably leads to different subtype classifications (Hoare, 1994; Macnab et al., 2001; Wu, Lin, & Zhu, 2007; Zhu et al., 2010). In general, the results of this work have led to subtypes characterized by a generalized motor deficit or by difficulties in particular fundamental or functional abilities, such as balance ability, fine motor skills and ball control (Wright & Sugden, 1996; Wu et al., 2007; Zhu et al., 2010). Because the present study focuses specifically on the role of balance problems in relation to overweight and obesity in children with and without DCD, the descriptive approach was selected to classify DCD subtype groups. A subtype of children with DCD-BP has been consistently identified in most subtyping studies (Hoare, 1994; Macnab et al., 2001; Wu et al., 2007; Zhu et al., 2010). Previous studies have shown that children with DCD-BP had a marked sway in the center of pressure, either during the two-leg stance or in more difficult conditions like standing on the non-preferred leg with eyes closed (Geuze, 2003; Tsai, Wu, & Huang, 2008). Although previous studies have reported that obesity may be associated with poor motor coordination ability, particularly in relation to balance ability, these studies have been somewhat limited by small samples; this in turn affects the ability to make statistical comparisons within and between subtype groups of children with DCD. Therefore, the purpose of the present study was to compare the prevalence of overweight and obesity among TD children, children with DCD and balance problems (DCD-BP), and children with DCD and no balance problems (DCD-NBP). We hypothesized that the prevalence of overweight and obesity would be higher in the DCD-BP subtype group. When compared to those in the DCD-NBP and TD groups. Because there is inconsistency in the results concerning the relationship between balance and obesity between boys and girls in the published literature (Cairney et al., 2010; Graf et al., 2004; Wagner et al., 2011), gender differences were also examined.
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2. Methods 2.1. Participants We recruited 18 elementary schools around Taiwan and randomly selected four classes in Grades 3–6 from each school. Parents or guardians of the children aged 9–12 years received a letter with information regarding the purpose and procedures of this study and signed the informed consent before the children participated in this study. A total of 2057 children (1095 boys and 962 girls) agreed to participate in this study. Children with medical conditions that affect motor ability (e.g., cerebral palsy, muscular dystrophy or any physical impairment) or intellectual disabilities were excluded from this study. This study included participants with DCD-BP (N = 178), DCD-NBP (N = 329) and TD (N = 1087), excluding borderline DCD (N = 463) for analysis. This study was approved by the Ethical Committee of the National Taiwan University of Physical Education and Sport and was supported by the National Science Council in Taiwan. 2.2. Assessments 2.2.1. Subtypes of developmental coordination disorder (DCD) The Movement Assessment Battery for Children test (MABC test) (Henderson & Sugden, 1992) was used to screen participants. The MABC consists of eight age-specific testing items and has three subscales that measure manual dexterity, ball skills, and static and dynamic balance. The Movement ABC test was administered by trained research assistants. After the assessment, the raw score of each item is converted into a scaled score ranging from 0 and 5 according to the test manual (Henderson & Sugden, 1992). The sum of these testing scores provides a Total Impairment Scores (TIS), with a lower scores representing better motor coordination ability. When the TIS of a child is greater than 13.5, according to the norm of the MABC test, he or she was classified as having DCD. When the TIS score is between 10 and 13.5, a child was defined as borderline DCD. When the TIS score was less than 10, a child was defined as typically developing (Henderson & Sugden, 1992). In this study, data from children with borderline DCD were not included for further analysis and comparison. The MABC test has been shown to have good reliability and concurrent validity (Chow & Henderson, 2003; Croce, Horvat, & McCarthy, 2001), and is widely accepted internationally as a measure for assessing DCD (Henderson & Sugden, 1992) including Taiwan (Wu et al., 2010; Zhu, Wu, & Cairney, 2011). As noted previously, the descriptive approach was selected to classify subtypes of DCD-BP and DCD-NBP in the present study. Although previous studies have used a total balance score (TBS) at or below the 5th percentile as a cutoff for classifying children with DCD and BP (Geuze, 2003; Tsai et al., 2008), we selected a broader classification (cutoff at or below the 15th percentile on the TBS), identifying children both at risk for having balance problems, and those with balance problems (N = 2057). Part of the rationale for this is based on the previous literature which shows that children scoring at or below the 15th percentile on the M-ABC to be at greater risk for overweight and obesity, when compared to TD children (Cairney, Hay, Veldhuizen, & Faught, 2011). The 15th percentile cut-off for the TBS is a score of 6.5. The selection criteria for children with DCD-BP were TIS score 13.5 and TBS score >6.5. The selection criteria for the children with DCD-NBP were TIS score 13.5 and TBS score 6.5. 2.2.2. Anthropometry Trained research assistants measured body height of participants according to standard procedures. Body height was determined to the nearest 0.1 cm using a portable, medical stadiometer. Body weight (kg) was assessed using an electric scale (TBF-521, TANITA, Tokyo, Japan) and waist and hip circumferences were measured using a tape measurement. Body weight and height measurements were used to calculate body mass index (BMI) (kg/m2) for each participant. We used BMI to identify overweight and obesity because of its safety, practical advantages and strong correlation with direct adiposity measures derived from dual energy X-ray absorptiometry (Foo, Teo, Abdullah, Aziz, & Hills, 2013). In this study, the International Obesity Task Force (IOTF) reference was used to define overweight and obesity in children (Cole, Bellizzi, Flegal, & Dietz, 2000). The IOTF reference including age and gender specific cut-offs is used for children 2–18 years of age. The IOTF reference has been recognized as one of the most definitive sources for normative data to define overweight or obesity in the world, because it was developed from a database of 97,876 boys and 94,851 girls from birth to 25 years of age from six countries (i.e., Brazil, Great Britain, Hong Kong, Netherlands, Singapore, and USA). IOTF reference percentile curves were constructed using an LMS method, and BMI values of 25 and 30 at 18 years of age for boys and girls were tracked back to define BMI values for overweight and obesity at younger ages. According to Cole et al. (2000), the definition of overweight and obesity derived from their data are less arbitrary and more international than other data, allowing researchers, policy makers, or practitioners to make direct comparisons of the prevalence of pediatric obesity around the world. 2.3. Statistical analysis Statistical analyses were carried out using the SPSS version 17.0 for Windows (SPSS Inc., Chicago, IL). The descriptive statistics for the anthropometric data and motor coordination ability are provided. A two-way analysis of variance (ANOVA)
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Table 1 Difference in anthropometric characteristics and motor coordination ability between TD, DCD-BP and DCD-NBP children. DCD-BP
TD
Demographic data Age (year)a Height (cm)a,c Weight (kg)a,b BMI (kg/m2)a,b Waist circumference Hip circumferencea WHRa,b
a,b
MABC scores Manual dexteritya,b,c Ball skillsa,b,c Total balance scorea Total impairment scorea,c
DCD-NBP
Group post hoc
Boys (N = 631)
Girls (N = 456)
Boys (N = 85)
Girls (N = 93)
Boys (N = 143)
Girls (N = 186)
10.57 1.11 145.79 10.36 41.48 11.90 19.22 3.71 65.71 13.20 77.83 13.51 0.84 0.06
10.47 1.11 144.97 9.62 38.21 9.91 17.96 3.17 62.22 12.16 77.04 13.47 0.81 0.06
11.08 0.79 147.39 9.51 47.87 12.93 21.76 4.33 72.79 14.63 83.16 13.74 0.87 0.07
11.27 0.81 150.82 8.65 45.60 11.55 19.90 4.12 67.95 12.48 82.99 13.75 0.82 0.06
10.20 0.97 142.42 10.13 40.73 13.47 19.65 4.36 67.15 13.99 77.70 13.81 0.86 0.06
10.10 0.86 141.79 8.97 36.88 8.95 18.12 2.94 61.71 13.49 74.51 14.64 0.83 0.07
BP > TD > NBP BP > TD > NBP BP > TD, NBP BP > TD, NBP BP > TD, NBP BP > TD, NBP BP, NBP > TD
6.78 3.13 3.95 2.91 8.68 1.95 19.42 5.48
4.13 2.91 5.32 2.55 8.85 1.81 18.30 3.69
7.99 2.58 4.20 2.51 4.19 1.46 16.38 2.61
6.28 2.54 6.18 2.46 3.69 1.51 16.15 2.50
NBP > BP > TD NBP > BP > TD BP > NBP > TD BP > NBP > TD
2.29 2.01 0.79 1.19 2.56 1.98 5.64 2.44
2.06 2.01 1.66 1.78 2.33 2.01 6.06 2.40
Note. BMI: body mass index; WHR: waist to hip ratio; BP: DCD-BP; NBP: DCD-NBP. a Main effects of groups, p < .001. b Main effects of genders, p < .001 c Interaction effects of group gender, p < .05.
with Scheffe’s post hoc was conducted to examine the main effects of group, gender, and the group gender interactions. We selected the Scheffe’s test because it is the most conservative with respect to Type I error (Hair, Black, Babin, Anderson, & Tatham, 2006). A Pearson Chi-Square analysis was used to compare the prevalence of overweight and obese children across the DCD-BP, DCD-NBP, and TD groups. Odds ratio (OR) with 95% confidence intervals (CI) was calculated to estimate obesity risk. A p-value less than 0.05 was set as the minimum threshold for statistical significance. 3. Results The main effect for group was significant for the anthropometric characteristics and MABC scores (Table 1). Most of the anthropometric data (e.g., weight; waist circumference) were higher in the DCD-BP group compared with the other two groups. Children in the DCD-NBP had higher subscale scores (higher scores indicate greater impairments) in manual dexterity and ball skills than those of the DCD-BP and TD groups. The total balance scores and total impairment score were significantly higher in the DCD-BP group, when compared to the DCD-NBP and TD groups. The main effect of gender was also significant for manual dexterity and ball skills: Girls had higher scores than boys in the manual dexterity domain; boys had higher scores than girls in the ball skills domain. There was also a significant interaction effect between gender and group for manual dexterity, ball skills, and total impairment scores (Table 1). Table 2 shows the prevalence of obesity, overweight and normal weight in the TD, DCD-BP and DCD-NBP groups respectively. Prevalence was highest in the DCD-BP group (15.2%), compared to the DCD-NBP (9.1%) and TD groups (7.5%) (x2 = 12.37, df = 4, p < .05). Although the prevalence of overweight was higher in the DCD-BP and DCD-NBP groups than those in the TD group, these differences were not statistically significant (x2 = 1.14, df = 2, p > .05). Compared with TD children, children in the DCD-BP group were more than twice as likely to be obese (OR = 2.28; 95% CI = 1.41–3.68; p < .01). DCD-BP children were also more likely to be obese compared to DCD-NBP children (OR = 1.79; 95% CI = 1.02–3.16; p < .05). Table 3 shows the prevalence of normal weight, overweight and obesity in TD, DCD-BP and DCD-NBP for boys and girls separately. Compared with TD girls, TD boys were more likely to be overweight (OR = 1.59; 95% CI = 1.17–2.12; p < .05) and obese (OR = 2.31; 95% CI = 1.39–3.84; p < .05). Similarly, DCD-BP boys were more than twice as likely to be overweight (OR = 2.20; 95% CI = 1.06–4.56; p < .05) and three times more likely to be obese (OR = 3.12; 95% CI = 1.28–7.57; p < .05) when compared to DCD-BP girls. DCD-NBP boys were also more likely to be obese when compared to DCD-NBP girls (OR = 2.67; 95% CI = 1.21–5.89; p < .05). Although the prevalence of overweight was higher in DCD-NBP boys when compared to DCDNBP girls, the difference was not statistically significant (x2 = 1.64, df = 1, p > .05).
Table 2 Prevalence of normal weight, overweight and obesity among three groups.
Normal-weight Overweight Obese
TD (N = 1087)
DCD-BP (N = 178)
DCD-NBP (N = 329)
761 (70.0%) 244 (22.4%) 82 (7.5%)
110 (61.8%) 41 (23.0%) 27 (15.2%)
219 (66.6%) 80 (24.3%) 30 (9.1%)
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Table 3 Prevalence of normal weight, overweight and obesity in TD, DCD-BP and DCD-NBP boys and girls. DCD-BP
TD
Normal-weight Overweight Obese
DCD-NBP
Girl (N = 456)
Boy (N = 631)
Girl (N = 93)
Boy (N = 85)
Girl (N = 186)
Boy (N = 143)
349 (76.5%) 85 (18.6%) 22 (4.8%)
412 (65.3%) 159 (25.2%) 60 (9.5%)
67 (72.0%) 17 (18.3%) 9 (9.7%)
43 (50.6%) 24 (28.2%) 18 (21.2%)
133 (71.5%) 42 (22.6%) 11 (5.9%)
86 (60.1%) 38 (26.6%) 19 (13.3%)
4. Discussion This study investigated the prevalence of overweight and obesity on two subtypes of children with DCD: Those with and without balance problems. We hypothesized that the prevalence of overweight and obesity would be higher in the DCD-BP subtype than those in the DCD-NBP and TD groups. Our hypothesis is supported by the findings that children with a subtype of DCD-BP have a higher obese risk in comparison to children with DCD-NBP and TD. It is often observed that many children with DCD demonstrate an awkward running pattern, fall frequently, and have a difficulty in imitating body positions. Because of their motor problems, including poor balance control, children with DCD perform poorly in sporting events such as track and field and ball activities. Overtime these children may become frustrated and avoid participating in sports activities altogether. Reduced time spent in physical activities further retards the development of movement skills and finally may result in decreased physical fitness and health conditions (Schott et al., 2007). Many empirical studies have confirmed that children with DCD have lower levels in physical activities and fitness compared to their peers (Rivilis et al., 2011; Wu et al., 2010). Low physical fitness is moderately to highly associated with a higher risk of obesity and several empirical studies have demonstrated that children with DCD were more likely to be overweight or obese compared to TD children (Cairney et al., 2010; Schott et al., 2007; Zhu et al., 2011). Physical activity is defined as any bodily movement produced by skeletal muscles that require energy expenditure. Most physical activities using large muscle groups such as walking, running, jumping, cycling, or participating in sports, require adequate balance abilities. This may be one of the reasons that DCD-BP children were more likely to be obese compared to DCD-NBP and TD children. In this study, however, we could not compare physical activities among children with DCD-BP, DCD-NBP and TD. A causal link between balance ability, physical activities and weight status cannot therefore be determined empirically. Hence, this crucial notion needs to be confirmed by direct examinations and further evidence. However, other explanations for a link between DCD, balance problems and obesity need to also be considered. Various studies have suggested that excessive increases in weight bearing forces caused by obesity may have a negative effect on the feet (D’Hondt et al., 2011; Dowling, Steele, & Baur, 2001; Riddiford-Harland, Steele, & Baur, 2011). Due to the continuous increased loading on the feet as a result of the excess body weight, childhood overweight and obesity may cause actual changes in foot structure. Overweight or obese children displayed significantly lower plantar arch height, larger foot dimensions, larger contact areas with the ground, and increased plantar pressure values than their non-obese counterparts (Dowling et al., 2001; Riddiford-Harland et al., 2011). These structural differences may reduce the quality and quantity of the sensory information from the mechanoreceptors within the plantar surface, which could contribute to the maintenance of postural stability (Hue et al., 2007). Furthermore, obesity affects the speed and kinematics of gait, static and dynamic balance in children, which may influence skill acquisitions (Colne, Frelut, Peres, & Thoumie, 2008). Recently, Castetbon and Andreyeva (2012) and Roberts et al. (2012) also found that balance skills involving hopping, jumping and backwards walking were more difficult for obese children compared with their peers who were not obese. Such locomotor competences are likely to be directly related to the excess weight and impaired musculoskeletal functions of obese children (Castetbon & Andreyeva, 2012). In addition, several studies have reported that overweight and obesity affects gross motor skills, not manipulative motor task and fine motor skills in young children (Castetbon & Andreyeva, 2012; Roberts et al., 2012; Wagner et al., 2011; Zhu et al., 2011). Our findings are similar to those recent studies that have indicated DCD-BP children were more likely to be obese compared to DCD-NBP children (OR = 1.79). Our findings were consistent with results shown in a previous study that boys had a higher obese risk compared to girls among DCD-BP and DCD-NBP groups (Wagner et al., 2011). In contrast with previous research suggesting the existence of no gender differences (Cairney et al., 2010; Graf et al., 2004), our results are consistent with research showing increased risk of obesity in children with DCD is specific to boys only (Cairney et al., 2012). The gender difference in motor performance may reflect different sociocultural influences on boys and girls (Cairney et al., 2010, 2012; Graf et al., 2004; Zhu, Li, & Wu, 2008). In Taiwan, particularly, boys with or without DCD were more obese and overweight than girls (Zhu et al., 2011). On the other hand, we also found gender differences in the kinds of activities which children were willing to and able to participate in: Boys tended to choose ball activities and expressed a desire to be good at such activities (Zhu et al., 2008). Girls, conversely, appear to be interested in activities that encourage the development of static and dynamic balance (Mickle, Munro, & Steele, 2011; Wagner et al., 2011). The strength of our present study includes the large sample size, which allowed us to make statistical comparisons within and between groups on the basis of both gender and DCD-subtype simultaneously. To our knowledge, this is the first
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empirical study that has examined the risk of obesity in children, across different subtypes of DCD. Nevertheless, a number of limitations still need to be considered. The current study did not include any measures of physical activity, lifestyle and physical fitness, and hence the assumption of a mediated impact remains hypothetical. This is a cross-sectional design and so a causal relationship between other influencing variables can only be hypothesized. Future research using a longitudinal, cohort design is required to establish causality. 5. Conclusion and implications This study identified that a subtype of children with DCD and balance problem were at significantly increased risk for obesity compared to typically developing children and children with DCD and no balance problem. We may expect that obese or overweight children with DCD and balance problem may also have poorer physical fitness and health compared to other children. These findings suggest that the inclusion of regular physical activity, particularly in relation to balance activities, may be important for the prevention of obesity or overweight in children. In the future, more longitudinal studies monitoring changes between obesity, physical activity, fitness, and motor coordination ability in different ages and genders of children and adolescents are urgently needed. Acknowledgements This study was supported by National Science Council in Taiwan (NSC98-2410-H-028-006 & 100-2314-B-028-001). We were greatly appreciative of the participation of children, parents and school staff in this study. Dr. Cairney is supported by an endowed professorship in child health through the Department of Family Medicine at McMaster University. References American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th text revision ed.). Washington, DC: Author. Barnhart, R. C., Davenport, M. J., Epps, S. B., & Nordquist, V. M. (2003). Developmental coordination disorder. Physical Therapy, 83(8), 722–731. Cairney, J., Hay, J., Veldhuizen, S., & Faught, B. E. (2011). Assessment of body composition using whole body air-displacement plethysmography in children with and without developmental coordination disorder. Research in Developmental Disabilities, 32, 830–835. http://dx.doi.org/10.1016/j.ridd.2010.10.011 Cairney, J., Hay, J. A., Veldhuizen, S., Missiuna, C., Mahlberg, N., & Faught, B. E. (2010). Trajectories of relative weight and waist circumference among children with and without developmental coordination disorder. Canadian Medical Association Journal, 182, 1167–1172. http://dx.doi.org/10.1503/cmaj.091454 Cairney, J., Kwan, M. Y., Hay, J. A., & Faught, B. E. (2012). Developmental coordination disorder, gender, and body weight: Examining the impact of participation in active play. Research in Developmental Disabilities, 33, 1566–1573. http://dx.doi.org/10.1016/j.ridd.2012.02.026 Castetbon, K., & Andreyeva, T. (2012). Obesity and motor skills among 4 to 6-year-old children in the United States: Nationally-representative surveys. BMC Pediatrics, 12, 28. http://dx.doi.org/10.1186/1471-2431-12-28 Chow, S. M. K., & Henderson, S. E. (2003). Interrater and test–retest reliability of the Movement Assessment Battery for Chinese preschool children. American Journal of Occupational Therapy, 57, 574–577. Cole, T. J., Bellizzi, M. C., Flegal, K. M., & Dietz, W. H. (2000). Establishing a standard definition for child overweight and obesity worldwide: International survey. British Medical Journal, 320, 1–6. http://dx.doi.org/10.1136/bmj.320.7244.1240 Colne, P., Frelut, M. L., Peres, G., & Thoumie, P. (2008). Postural control in obese adolescents assessed by limits of stability and gait initiation. Gait & Posture, 28, 164–169. http://dx.doi.org/10.1016/j.gaitpost.2007.11.006 Croce, R. V., Horvat, M., & McCarthy, E. (2001). Reliability and concurrent validity of the Movement Assessment Battery for Children. Perceptual and Motor Skills, 93, 275–280. D’Hondt, E., Deforche, B., De Bourdeaudhuij, I., Gentier, I., Tanghe, A., Shultz, S., et al. (2011). Postural balance under normal and altered sensory conditions in normal-weight and overweight children. Clinical Biomechanics, 26, 84–89. http://dx.doi.org/10.1016/j.clinbiomech.2010.08.007 D’Hondt, E., Deforche, B., De Bourdeaudhuij, I., & Lenoir, M. (2008). Childhood obesity affects fine motor skill performance under different postural constraints. Neuroscience Letters, 440, 72–75. http://dx.doi.org/10.1016/j.neulet.2008.05.056 Dowling, A. M., Steele, J. R., & Baur, L. A. (2001). Does obesity influence foot structure and plantar pressure patterns in prepubescent children? International Journal of Obesity, 25, 845–852. Foo, L. H., Teo, P. S., Abdullah, N. F., Aziz, M. E., & Hills, A. P. (2013). Relationship between anthropometric and dual energy X-ray absorptiometry measures to assess total and regional adiposity in Malaysian adolescents. Asia Pacific Journal Clinical Nutrition, 22, 348–356. Graf, C., Koch, B., Kretschmann-Kandel, E., Falkowski, G., Christ, H., Coburger, S., et al. (2004). Correlation between BMI, leisure habits and motor abilities in childhood (CHILT-project). International Journal of Obesity, 28, 22–26. http://dx.doi.org/10.1038/sj.ijo.0802428 Geuze, R. H. (2003). Static balance and developmental coordination disorder. Human Movement Science, 22, 527–548. http://dx.doi.org/10.1155/NP.2005.183 Hair, J. F., Black, W. C., Babin, B. J., Anderson, R. E., & Tatham, R. L. (2006). Multivariate data analysis (6th ed., pp. 424–). New Jersey: Pearson Prentice Hall. Henderson, S. E., & Sugden, D. A. (1992). Movement assessment battery for children (1st ed.). London: The Psychological Corporation. Hoare, D. (1994). Subtypes of developmental coordination disorder. Adapted Physical Activity Quarterly, 11, 158–169. Hue, O., Simoneau, M., Marcotte, J., Berrigan, F., Dore´, J., Marceau, P., et al. (2007). Body weight is a strong predictor of postural stability. Gait & Posture, 26, 32–38. http://dx.doi.org/10.1186/1743-0003-8-20 Li, Y. C., Wu, S. K., Cairney, J., & Hsieh, C. Y. (2011). Motor coordination and health-related physical fitness of children with developmental coordination disorder: A three-year follow-up study. Research in Developmental Disabilities, 32, 2993–3002. http://dx.doi.org/10.1016/j.ridd.2011.04.009 Macnab, J. J., Miller, L. T., & Polatajko, H. J. (2001). The search for subtypes of DCD: Is cluster analysis the answer? Human Movement Science, 20, 49–72. http:// dx.doi.org/10.1016/S0167-9457(01)00028-8 McGraw, B., McClenaghan, B. A., Williams, H. G., Dickerson, J., & Ward, D. S. (2000). Gait and postural stability in obese and nonobese prepubertal boys. Archives of Physical Medicine and Rehabilitation, 81, 484–489. http://dx.doi.org/10.1053/mr.2000.3782 Mickle, K. J., Munro, B. J., & Steele, J. R. (2011). Gender and age affect balance performance in primary school-aged children. Journal of Science and Medicine in Sport, 14, 243–248. http://dx.doi.org/10.1016/j.jsams.2010.11.002 Missiuna, C., Moll, S., King, S., King, G., & Law, M. (2007). A trajectory of troubles: Parents’ impressions of the impact of developmental coordination disorder. Physical & Occupational Therapy in Pediatrics, 27(1), 81–101. Okely, A. D., Booth, M. L., & Chey, T. (2004). Relationships between body composition and fundamental movement skills among children and adolescents. Research Quarterly for Exercise and Sport, 75, 238–247. http://dx.doi.org/10.1080/02701367.2004.10609157 Riddiford-Harland, D. L., Steele, J. R., & Baur, L. A. (2011). Are the feet of obese children fat or flat? Revisiting the debate. International Journal of Obesity, 35, 115–120. http://dx.doi.org/10.1038/ijo.2010.119
Y.-C. Zhu et al. / Research in Developmental Disabilities 35 (2014) 1727–1733
1733
Rivilis, I., Hay, J., Cairney, J., Klentrou, P., Liu, J., & Faught, B. E. (2011). Physical activity and fitness in children with developmental coordination disorder: A systematic review. Research in Developmental Disabilities, 32, 894–910. http://dx.doi.org/10.1016/j.ridd.2011.01.017 Roberts, D., Veneri, D., Decker, R., & Gannotti, M. (2012). Weight status and gross motor skill in kindergarten children. Pediatric Physical Therapy, 24, 353–360. http://dx.doi.org/10.1097/PEP.0b013e3182680f19 Schott, N., Alof, V., Hultsch, D., & Meermann, D. (2007). Physical fitness in children with developmental coordination disorder. Research Quarterly for Exercise and Sport, 78, 438–450. http://dx.doi.org/10.1080/02701367.2007.10599444 Tsai, C. L., Wu, S. K., & Huang, C. H. (2008). Static balance in children with developmental coordination disorder. Human Movement Science, 27, 142–153. http:// dx.doi.org/10.1016/j.humov.2007.08.002 Visser, J. (2003). Developmental coordination disorder: A review of research on subtypes and comorbidities. Human Movement Science, 22, 479–493. http:// dx.doi.org/10.1016/j.humov.2003.09.005 Wagner, M. O., Kastner, J., Petermann, F., Jekauc, D., Worth, A., & Bo¨s, K. (2011). The impact of obesity on developmental coordination disorder in adolescence. Research in Developmental Disabilities, 32, 1970–1976. http://dx.doi.org/10.1016/j.ridd.2011.04.004 Wright, H. C., & Sugden, D. A. (1996). The nature of developmental coordination disorder: Inter- and intragroup differences. Adapted Physical Activity Quarterly, 13, 357–371. Wu, S. K., Lin, H. H., Li, Y. C., Tsai, C. L., & Cairney, J. (2010). Cardiopulmonary fitness and endurance in children with developmental coordination disorder. Research in Developmental Disabilities, 31, 345–349. http://dx.doi.org/10.1016/j.ridd.2009.09.018 Wu, S. K., Lin, K. H., & Zhu, Y. C. (2007). Analysis of subgroups of children with developmental coordination disorder based on Movement ABC test. Health Promotion Science, 2, 95–105. Zhu, Y. C., Li, Y. C., & Wu, S. K. (2008). Changes of motor coordination ability in 9 and 10 year-old children in Taiwan. Health Promotion Science, 3, 11–22. Zhu, Y. C., Li, Y. C., & Wu, S. K. (2010). Subtypes of children with developmental coordination disorder in Taiwan. Formosan Journal of Physical Therapy, 35, 243–250. Zhu, Y. C., Wu, S. K., & Cairney, J. (2011). Obesity and motor coordination ability in Taiwanese children with and without developmental coordination disorder. Research in Developmental Disabilities, 32, 801–807. http://dx.doi.org/10.1016/j.ridd.2010.10.020
