Abstract
round:Children with motor delays often experience challenges in health- related fitness, but the impact on running skills remains unclear. Previous research has shown that children with motor coordination problems have lower cardiorespiratory fitness, muscle strength, endurance, and higher body weight compared to peers. Few studies have examined anaerobic capacity, muscular power, endurance, running performance, and fatigue in children with developmental coordination disorder (DCD). This study aims to compare repetitive running and running-induced fatigue in typically developing children and those with varying degrees of motor coordination problems.Methods:Groups were classified using the Movement Assessment Battery for Children, second edition (MABC-2), as probably having DCD (p-DCD,≤5th percentile, age 9.7 (SD 1.6), n = 141), at risk for DCD (r-DCD, 6th–16th percentile, age 9.9 (SD1.6), n = 160), and typically developing (TD, >16th percentile, age 9.6 (SD 1.6), n = 191). Anaerobic fitness and fatigue were assessed using the Children’s Repetitive and Intermittent Sprinting Performance test (CRISP), while lower and upper body muscular strength, running, and agility were measured with the performance and fitness (PERF-FIT) test battery Power and Agility subscale. Age groups (6–9 and 10–12 years) were analyzed to determine when performance deficits emerged.Results: The p-DCD group was significantly slower, had less power, and fatigued more than
the Children’s Repetitive and Intermittent Sprinting Performance test (CRISP), while lower and upper body muscular strength, running, and agility were measured with the performance and fitness (PERF-FIT) test battery Power and Agility subscale. Age groups (6–9 and 10–12 years) were analyzed to determine when performance deficits emerged.Results: The p-DCD group was significantly slower, had less power, and fatigued more than the r-DCD and TD children (p< 0.01). This was already clearly the case in the 6–9-year-olds, who slowed down already after the first runs, while the older poorly coordinated children started slower than their peers and showed a more gradual decrease in performance over the runs.Conclusions:Moderate coordination differences between r-DCD and TD children did not significantly impact fatigue, but p-DCD children exhibited greater fatigue due to overestimating their start speed, higher body weight, lower power, and reduced agility, especially in younger age groups. (Too) High starting speed, especially in the younger less coordinated children (p-DCD), is likely to lead to more fatigue. Keywords:DCD; running; fatigue; motor competence; CRISP; PERF-FIT 1. Introduction Developmental coordination disorder (DCD) is the recommended diagnostic label for children experiencing pronounced coordination challenges that disrupt their abilities to engage in daily activities (e.g., getting dressed, brushing teeth, playing ball games) and academic tasks, which cannot be explained by any intellectual disability or identifiable neurological disease. These children tend to encounter difficulties in various activities, incorporating gross motor activities like running, jumping, throwing, and catching, as well Children2025,12, 135 https://doi.org/10.3390/children12020135
Children2025,12, 135 2 of 19 as fine motor activities including handwriting. The results of a recent review indicate that children with DCD have lower physical fitness performance compared to their typically developing (TD) peers [1]. Over the past decade, it has been well-documented that children who struggle with motor skills have lower levels of aerobic and anaerobic fitness [2–6]. The inability to acquire the appropriate motor skills greatly limits the development of a healthy level of physical fitness. They showcase decreased physical activity resulting in lower cardiorespiratory fitness levels, muscle strength, muscular endurance, and a higher body composition than their peers [7–9]. This means that the overall fitness levels (strength, anaerobic fitness, and aerobic capacity) need to be examined when an intervention program is developed for children with lower levels of motor skills as limitations in all these areas can be found [1]. Further, our meta-analysis suggests a need for motor assessments that more closely mirror real-life activities (i.e., ecological validity) across different performance domains. Although running is a daily activity for most children, running items, long enough to tap into the anaerobic capacity, are not included in the most frequently used motor performance tests. Most research has focused on investigating aerobic fitness of children with DCD because it is related to the risk for health problems such as cardiovascular disease [10–13]. However, predominantly anaerobic capacity is needed when running during active play or recreational sports. Yet in young children, only a few studies have focused on anaerobic capacity, which includes power, muscular endurance, and fatigue [10–13]. 1.1. Development of Running Running is a complex skill that is a combination of coordination, motor planning, agility, and strength and is often overlooked as an important skill that also needs to be learned and later trained [14–16]. To understand the mechanism of running, one should first look at the three developmental stages of running. Usually, children begin to run around the age of two, and this is long before they partake in any organized physical activities. During the early stages, also known as the initial or discovery stage of running, it will
learned and later trained [14–16]. To understand the mechanism of running, one should first look at the three developmental stages of running. Usually, children begin to run around the age of two, and this is long before they partake in any organized physical activities. During the early stages, also known as the initial or discovery stage of running, it will seem like the child’s arm swing appears stiff and arms are swinging out from the body. The leg swing is also very limited, and the legs make uneven strides with no obvious flight phase visible. Lastly, with no flight phase present, there will always be one foot on the ground, and the child will have a wider base of support while running to maintain balance [14–19]. The next stage, also known as the intermediate or developing stage, usually occurs when the child is between the ages of three and six years. In this stage, the arm swing starts to move closer to the body and arms are swung further to the front and back. The leg swing improves, leading to an increase in speed and improved stride length. The stance leg also starts to straighten more during the push-off phase to give more momentum. Lastly, a limited flight phase is evident where both feet are off the ground for a brief moment. The final stage of the development of the running skill is the mature or consolidating stage, which usually occurs between six and nine years. In this stage, children start to run more like adults with their arms that are bent at a 90 ◦ angle at the elbows, demonstrating an arm swing that is close to the body in the opposite direction of the leg movement. Furthermore, a larger stride length with a definite flight phase is visible. The supporting leg bends slightly upon contact with the ground and then straightens to propel the body upwards during the push-off phase, which increases the running speed [17–19]. Agility, strength, and muscular power are all factors integrated during the devel- opment of the running phases. During these phases, the center
larger stride length with a definite flight phase is visible. The supporting leg bends slightly upon contact with the ground and then straightens to propel the body upwards during the push-off phase, which increases the running speed [17–19]. Agility, strength, and muscular power are all factors integrated during the devel- opment of the running phases. During these phases, the center of mass of the body exhibits a motion comparable to a mass attached to a weightless spring, rebounding off the ground [20–23] and oscillating around an equilibrium point where the vertical force equals
Children2025,12, 135 3 of 19 the body weight. Equilibrium point models describe running economy based on spring-like behaviors of the musculoskeletal system. During the first part of the contact phase on the stance leg, the spring–mass system is compressed, and potential elastic energy is stored in the muscle–tendon units of the lower limb to be further released during the second part of contact when the spring expands. This stored energy helps with power generation in the push-off phase to get the body into the next flight phase. A longer flight phase demands greater power generated during the contact phase to accelerate and lift the body appropriately. Learning to exploit these elastic properties will improve running efficiency. 1.2. Running with DCD Running is a fundamental movement skill that is not only important for participat- ing in playground activities but also for development of fitness and overall health [24]. Running should therefore be seen as an integrated part of many physical activities, and if development is delayed, this could impact participation in these activities [17–19,25]. The results of the Diamond study [26] suggested that children with DCD run with a slower and less efficient running style compared with TD children. One of the reasons could be that children with DCD struggle with the coordination of the running pattern [27] and the efficient use of strength and power. Even in walking, children with DCD tend to be slower with a shorter stride length with less ankle range of movement than TD children [28,29]. According to research by Cairney [30] and Diamond [26], possible reasons for poor running could be due to slower contraction speed and lower ankle plantar flexor power. This leads to compensatory hip flexor movements at the push-off phase and could also affect the release of the potential elastic energy normally stored in the muscle–tendon system. The reduced running speed in children with DCD could be linked to their ineffectiveness in applying the absorption/generation plantar flexor strategy while running, which in turn could restrict their running speed or induce earlier exertion. 1.3. Repetitive Sprinting and Fatigue The ability to produce a
also affect the release of the potential elastic energy normally stored in the muscle–tendon system. The reduced running speed in children with DCD could be linked to their ineffectiveness in applying the absorption/generation plantar flexor strategy while running, which in turn could restrict their running speed or induce earlier exertion. 1.3. Repetitive Sprinting and Fatigue The ability to produce a stable running performance over a series of sprints with short recovery is called repetitive sprinting ability [31]. A test to measure repeated sprinting performance and fatigue is the Children’s Repetitive and Intermittent Sprinting Perfor- mance test or CRISP. Fatigue can be seen as a continuous, multifaceted process that occurs during high-intensity exercise, for example, while sprinting [32,33]. It includes both central and peripheral mechanisms that temporarily reduce the power-generating capacity of the integrated neuromuscular system. Fatigue also refers to the inability to continue with a given activity or exercise at a given intensity. It is therefore important to understand how children with DCD experience fatigue, if this is different from their TD peers, and if fatiguing during sprinting is different in younger and older children [32,33]. Currently, one study investigated if the CRISP test could induce fatigue among school- aged children (7–12 years) and tested the validity of the test in children with probable DCD (p-DCD) and TD peers [12]. These researchers reported that the CRISP test could be used to induce fatigue among children. It was also reported that children with p-DCD exhibited lower anaerobic capacity, including muscular power and muscular endurance, in comparison to their TD peers. Despite this, fatigue levels were similar between the two groups. However, one of the limitations of this study was that only a small number of children (n = 42) were evaluated, and the study lacked power for the groups to be divided into different motor proficiency groups and age groups. Several studies have been published, indicating that children with DCD usually have a higher body mass index (BMI) than their peers [34–38], and it is well-known that body weight could also have an impact on a child’s endurance and running skills
and the study lacked power for the groups to be divided into different motor proficiency groups and age groups. Several studies have been published, indicating that children with DCD usually have a higher body mass index (BMI) than their peers [34–38], and it is well-known that body weight could also have an impact on a child’s endurance and running skills [39–41]. The
Children2025,12, 135 4 of 19 study conducted by Haapala and associates [41] on children between the ages of six and eight years reported that children who had higher body fat percentages performed poorer in the different running and jumping tests than their peers. A reason could be that during these skills children have to carry their weight, which could compromise musculoskeletal functions, especially in overweight and obese children [39,42]. To conclude, it was indicated that children with DCD tend to produce less optimal movement patterns than their peers, leading to slower running and possibly early exertion. Physical fatigue so far was only reported in one study. Other factors to take into account are the reported lower strength and power and the higher prevalence of being overweight in children with DCD. Therefore, this study aimed to compare sprinting time, power, and fatigue during repetitive sprinting in 6–12-year-old children with different levels of motor competence and in different age groups. The MABC-2 total score was used to define the three motor coordination groups. This study had the following three sub-aims. (1)To confirm that children with lower MABC-2 scores are slower in repetitive sprinting. To test if this lower performance is already present in young children (6–9 years) or only in older ones (10–12 years). (2)To examine if induced fatigue (decay in performance) during repetitive sprinting (CRISP test) is larger in children who score lower on the classification of the MABC-2. If so, to test if the increase in running time and reduction in power are age group- dependent (6–9 years versus 10–12 years). (3)To study if BMI, functional strength (power lower and upper extremities), agility (ladder run, ladder step, and side jump), and motor performance (MABC-2) are important explanatory factors for the level of fatigue on the CRISP. Considering previous studies, it was hypothesized that children with probable DCD (p-DCD), compared to typical developed children (TD), would show a longer running time, lower power, and higher fatigue indexes during running compared to TD. The at-risk-for-DCD (r-DCD) group is expected to show results between the p-DCD and TD. 2. Materials and Methods 2.1.
level of fatigue on the CRISP. Considering previous studies, it was hypothesized that children with probable DCD (p-DCD), compared to typical developed children (TD), would show a longer running time, lower power, and higher fatigue indexes during running compared to TD. The at-risk-for-DCD (r-DCD) group is expected to show results between the p-DCD and TD. 2. Materials and Methods 2.1. Study Design This study was an observational cross-sectional case-controlled study including r- DCD, p-DCD, and TD groups. Data were gathered from children aged 6–12 years, obtained during the years 2019, 2022, and 2023, as part of the PERF-FIT study. 2.2. Participant Selection Children in grades 1–6 of four schools were invited to participate. All children whose parents signed the written informed consent and gave assent themselves were included (n = 500). Children’s motor coordination was measured using the Movement Assessment Battery for Children-2 (MABC-2 test) [43]. Of the 500 children, 191 children scored above the 16th percentile on the MABC-2 test (TD), 162 scored at or below the 16th percentile and above the 5th (at risk for DCD), and 147 children scored at or below the 5th percentile (probable DCD) on the MABC-2 test. Because not all the DSM-5 criteria could be confirmed, the group identified as having severe movement difficulties will be referred to as p-DCD group [44]. After checking the data for outliers and missing values, data of 5 children were taken out (2 were extremely slow on the CRISP, both p-DCD, and 3 children had 1 item that was scored as fail (F); so, no total MABC-2 scores were available). Data were analyzed for 216 children between 6 and 9 years old and 284 children between 10 and 12 years of age (see Table).
Children2025,12, 135 5 of 19 Table 1.Characteristics of participants. Variables TD Mean (n = 191) SD r-DCD Mean (n = 162) SD p-DCD Mean (n = 146) SD Age (years) 9.6 1.6 9.9 1.6 9.7 1.6 Weight (kg) 31.4 8.5 32.4 7.6 33.6 10.1 Height (cm) 136.5 11.6 137.9 10.7 137.3 11.2 BMI (kg m −2 ) 16.6 2.7 16.9 2.5 17.6 * 3.7 MABC-2 (TSS) 9.8 1.7 6.4 ** 0.4 3.9 ** 1.2 BMI: Body mass index, MABC-2 test: Movement Assessment Battery for Children test, second edition, TSS: total standard score, SD: standard deviation, TD: typically developing children, r-DCD: at risk for developmental coordination disorder, and DCD: developmental coordination disorder. * Statistically significant between TD and p-DCD groups atp< 0.01. ** Statistically significant between TD and r-DCD groups and p-DCD and r-DCD at p< 0.01. 2.3. Measurements 2.3.1. Movement Assessment Battery for Children Test-2 (MABC-2 Test) The Movement Assessment Battery for Children, second edition (MABC-2), is a test that can be used to identify children between the ages of 3 and 16 years with impaired motor function [43]. The test consists of three age bands: age band one (3 to 6 years), age band two (7 to 10 years), and age band three (11 to 16 years). For this study, only age band two was used. There are eight test items in each age band, with three categories, namely, manual dexterity, aiming and catching, and balance. The raw score was converted to a standard score and percentile. Percentile scores of 5 or less indicate severe motor problems, while a score between 6 and 16 suggests the child is at risk of having movement difficulties. A percentile ranking above 16 indicates performance in the normal range of the tested motor skills. The test is a reliable measuring instrument with a test–retest reliability of 0.88–0.99 for the component scores and 0.97 for the total test scores [45]. Since there were no valid motor tests with norms for African countries, we elected to use the Dutch norms, as was done in our earlier studies involving South African children to make the studies
skills. The test is a reliable measuring instrument with a test–retest reliability of 0.88–0.99 for the component scores and 0.97 for the total test scores [45]. Since there were no valid motor tests with norms for African countries, we elected to use the Dutch norms, as was done in our earlier studies involving South African children to make the studies comparable [2,46]. 2.3.2. The Children’s Repetitive and Intermittent Sprinting Performance (CRISP) Test The CRISP test was used to evaluate anaerobic fitness and fatigue in the participants. This assessment comprised of six 30 m sprints at maximum speed, combined with brief recovery periods. Each participant was required to sprint as rapidly as possible from one line to the other, with explicit instructions not to decelerate before crossing the finish line. Sprint times, as taken with stopwatches, indicating the time taken to complete each run, were recorded as a key metric. Before the test, each child underwent a 1 min warm-up, and the test protocol was thoroughly explained and demonstrated, either by the tester or by observing other children undergoing the same test, ensuring a clear understanding of the test requirements. Throughout the testing period, participants received verbal encouragement. To facilitate the comparison between the TD and DCD groups, additional outcomes were derived from the sprint times. Mean power (MP) was used as a measure of anaerobic capacity and was calculated using the sprint time of the six runs and the weight of each participant. Power was calculated by using the following formula: power [(body mass×distance 2 )/sprint time 3 ] [47]. Mean and peak power (Watts), which are the average and highest power output of all six sprints, were determined. Greater MP indicates the ability to maintain power output over time and translates into better maintenance of anaerobic performance. Fatigue was measured as a percentage of the difference between the slowest and fastest running times [fatigue index time = (slowest running time−fastest running time/fastest running time)×100]. Fatigue index power was calculated using the peak and low power data points over the six runs. The children participating in this study did not
Description
The study examines running performance and fatigue in children with different motor competencies.