Aertssen Wendy, Bonney Emmanuel, Ferguson Gillian, Smits-Engelsman Bouwien
Avans(+) University of Professionals, The Netherlands.
Department of Health & Rehabilitation Sciences, University of Cape Town, South Africa; Department of Physiotherapy, University of Ghana, Accra, Ghana.
Hum Mov Sci. 2018 Aug;60:87-97. doi: 10.1016/j.humov.2018.05.012. Epub 2018 May 28.
Children with Developmental Coordination Disorder (DCD) are known to have poor physical fitness. However, differentiating homogenous subgroups of DCD using fitness performance has not yet been established. Therefore the purpose of this study was to identify subtypes in children with and without DCD using measures of physical fitness.
Children (aged 6-10 years, n = 217) constituted the sample for this study. They were assessed on 1) aerobic fitness (20m Shuttle Run test), 2) anaerobic fitness (Muscle Power Sprint Test), 3) isometric muscle strength (handheld dynamometry) 4) functional upper and lower body strength (Functional Strength Measurement) and 5) motor coordination [Movement Assessment Battery for Children-2nd edition (MABC-2) test]. The Ward method was used to identify the various clusters.
Five subtypes emerged in the entire sample. In the typically developing (TD) children mainly 2 subtypes (number 5 and 2) were found containing 89% of the TD children (n = 55), with the largest group demonstrating above average performance on all measures (cluster 5). Children in subtype 2 had just above average motor coordination and good aerobic fitness but lower muscle strength. Subtypes 1, 3 and 4 were clearly "DCD" clusters, however they showed difference in fitness performance. Subtype 1 contained children with DCD who showed poor performance on all fitness outcomes (n = 45). Children with DCD in subtype 3 had poor aerobic but average strength and anaerobic fitness (n = 48). Subtype 4 contained children with DCD (n = 45) who had good muscle strength and anaerobic fitness. Of these, 36% were at risk of DCD while 24% had definite motor coordination problems.
Our findings indicate that children with and without DCD demonstrate heterogeneous physical fitness profiles. The majority of the children (66%) with DCD belonged to subtypes with lower fitness performance. Further studies are needed to confirm these findings in other samples of DCD children.
已知患有发育性协调障碍（DCD）的儿童身体素质较差。然而，尚未确定使用体能表现来区分DCD的同质亚组。因此，本研究的目的是通过体能测量来识别有或无DCD儿童的亚型。
儿童（6至10岁，n = 217）构成了本研究的样本。对他们进行了以下评估：1）有氧适能（20米穿梭跑测试）；2）无氧适能（肌肉力量冲刺测试）；3）等长肌肉力量（手持测力计）；4）功能性上、下肢力量（功能性力量测量）；5）运动协调性[儿童运动评估量表第二版（MABC - 2）测试]。采用沃德法来识别不同的聚类。
整个样本中出现了五个亚型。在发育正常（TD）的儿童中，主要发现了2个亚型（5型和2型），包含了89%的TD儿童（n = 55），最大的一组在所有测量指标上表现高于平均水平（聚类5）。2型亚型的儿童运动协调性略高于平均水平，有氧适能良好，但肌肉力量较低。1型、3型和4型明显是“DCD”聚类，但它们在体能表现上存在差异。1型包含在所有体能指标上表现较差的DCD儿童（n = 45）。3型DCD儿童有氧适能较差，但力量和无氧适能平均（n = 48）。4型包含肌肉力量和无氧适能良好的DCD儿童（n = 45）。其中，36%有DCD风险，24%有明确的运动协调问题。
我们的研究结果表明，有或无DCD的儿童表现出不同的体能特征。大多数（66%）患有DCD的儿童属于体能表现较低的亚型。需要进一步研究以在其他DCD儿童样本中证实这些发现。
