Abstract
OBJECTIVES. Youth with better motor abilities may find it easier to be physically active and may be more likely to engage in physical activity compared with peers with poorer motor competence. The purpose of this study was to examine the relationship between motor proficiency and physical activity in 8- to 10-year-old children. Self-efficacy toward physical activity was also assessed.
METHODS. Sixty-five children (34 girls and 31 boys) were studied. Children's physical activity was assessed by the Manufacturing Technologies Incorporated/Computer Science and Applications Incorporated model 7164 accelerometer, and their motor proficiency was determined by the Bruininks-Oseretsky Test of Motor Proficiency. The Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity scale measured children's self-perceptions of adequacy in performing and desire to participate in physical activities.
RESULTS. Children's motor proficiency was positively associated with activity counts and percentage of time in moderate and moderate-to-vigorous intensity physical activity and inversely related to percentage of time in sedentary activity. Children in the greatest quartile of motor proficiency were the most physically active compared with children with lower levels of motor proficiency who had similar levels of physical activity. Children with greater standardized BMI were less physically active, more sedentary, and had poorer motor proficiency compared with children with a lower standardized BMI. Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity scores were positively associated with Bruininks-Oseretsky Test of Motor Proficiency standard score for boys. Children's motor proficiency explained an additional 8.7% of the variance in physical activity in multiple linear regression after controlling for factors that may influence physical activity.
CONCLUSIONS. Motor proficiency is positively associated with physical activity and inversely associated with sedentary activity in children, but there may be a threshold of motor proficiency above which children may be the most physically active. Children's motor proficiency may be an appropriate target for increasing physical activity in youth.
Many children are less physically active than recommended, and physical activity declines as children get older.1,2 There are a number of factors positively associated with physical activity in youth, including self-efficacy in one's ability to overcome barriers to physical activity,3,4 perceptions of physical or sport competence,4,5 having positive attitudes toward physical education,4 enjoying physical activity,4,6 and parent, sibling, and peer support.4,5 An additional determinant of physical activity among children and adolescents may be the level of mastery of the movement skills that are a foundation for the skills used in common forms of adult physical activity.7,8 Movement skills track at low-to-moderate levels during childhood,9–12 so greater motor proficiency in youth may be predictive of later physical activity. Youth with better motor proficiency may find it easier to be physically active and may be more likely to engage in physical activity compared with peers with poorer motor skill competence. Children with poor motor proficiency may subsequently choose a more sedentary lifestyle to avoid these movement difficulties.13
Research has shown significant positive associations among motor skills,8 visual-motor coordination,13 gross motor development,14 and self-reported athletic coordination15 and physical activity in youth. This effect may be different for girls and boys based on differences in social acceptance for physical activity.16 In addition, the effect may not be linear but may be most important at the extremes of the distribution.17 Children with the poorest motor skills may be the most sedentary. Conversely, children who are the most coordinated may be the most physically active.17
There are several factors that may be related to lower levels of coordination in youth. For example, more overweight youth may be less coordinated than leaner youth,13–15 and this relationship may extend to infant weight and motor activity relationships.18 Motor skills may also be related to self-efficacy of confidence in physical activity.19 Decreased competence and confidence may lead children with movement difficulties to avoid participating in physical activities as a coping strategy.20
Although motor coordination has been consistently related to both physical activity and body weight, there are important limitations to these studies. Much of this research has relied on self-report rather than objective measures of physical activity and has not considered the effects of children's self-perception and self-adequacy for physical activity. Likewise, there has been an absence of use of a comprehensive, validated measure of gross and fine motor skills. Therefore, the purpose of this study was to examine the relationship between motor proficiency and physical activity in 8- to 10-year-old children using an objective measure of physical activity and a comprehensive measure of motor proficiency. It was hypothesized that youth with greater motor proficiency would be more physically active and that children's self-adequacy in and predilection for physical activity would be positively related to their physical activity and motor proficiency. This research has the potential to help us understand the relationship between motor proficiency and physical activity that could lead to the development of more effective strategies for increasing physical activity in youth.
METHODS
Participants
Children aged 8–10 years living in Erie County, New York, were recruited via letters mailed to families, flyers distributed to school systems, and a 1-week ad in local newspapers. Children were healthy and free from diagnosed orthopedic, neurologic, or developmental conditions that could create motor proficiency or physical activity impairments as determined by telephone screen. One parent/guardian participated with each child and agreed to assist children as necessary. Children who were in the ≥95th BMI percentile (overweight)21 were excluded to avoid potential effects that excess weight may have on physical activity and coordination.
Experimental Design
Each child and parent was seen for 2 visits. During the first visit, consent and assent forms were completed. Children then completed the Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity (CSAPPA) scale.22,23 The CSAPPA is a 20-item survey of children's self-perceptions of their adequacy in performing and desire to participate in physical activities. A total score and an adequacy, predilection, and enjoyment factor were computed. This scale is a reliable and valid measure of adequacy in and predilection for physical activity in children.19,22–25
Parents completed an environmental questionnaire that asked about the number of televisions and children in the home. Each parent also completed the Hollingshead's Four-Factor Index of Social Status26 to assess socioeconomic status (SES). Height and weight were then measured for each child and parent. Weight was measured in kilograms to the nearest tenth using a digital scale (BF-350; Tanita, Arlington Heights, IL) that was calibrated before each use against a standard weight. Height was measured in centimeters to the nearest hundredth using a digital stadiometer (Digi-Kit, North Bend, WA) that was calibrated against a standard height before each use. Height and weight were used to calculate BMI for which the percentage overweight was determined. Percentage overweight was calculated by the formula (BMI − BMI at the 50th BMI percentile)/BMI at the 50th BMI percentile.27
The Bruininks-Oseretsky Test of Motor Proficiency-Short Form28 (BOTMP) was then used to assess children's motor ability. The short form has been validated against the full scale and consists of 14 items taken from the 8 subtests that correlate highly with the subtest score and the total score. The 8 subtests assess gross motor development, including running speed and agility, balance, bilateral coordination, and strength; gross and fine motor development, including upper limb coordination; and fine motor development, including response speed, visual-motor control, and upper-limb speed and dexterity. A total standard score, adjusted for child age, was used to interpret test performance. The BOTMP is a standardized, product-oriented assessment commonly used in the assessment of motor abilities in children.12,29
Before leaving, children were taught how to wear a Manufacturing Technologies Inc (MTI) model 7164 Actigraph (formerly Computer Science and Applications Inc [CSA]) accelerometer, and each parent and child was given a habit book to record their physical and sedentary activities, confirm when the accelerometer was worn, and document sleep. The MTI/CSA has been extensively validated as a measure of physical activity in children.30,31 Accelerometers were placed in a pouch that attached to a belt that children wore around their waist. Children were instructed to wear the accelerometers for ≥6, preferably 7, days of the week for 1 week for a minimum of 10 hours/day and to record each time the device is put on and taken off. Each child was instructed to wear the accelerometer during “typical days” and told that if it was not a typical day, to wear the accelerometer during the next typical day, and to make up the missed day so they would have a week's worth of activity. On returning to the laboratory after wearing the accelerometer for 7 days, it was downloaded, and on and off times for each day were determined. The times were examined and discrepancies resolved by review with the parent and child with the aid of their habit books. The average number of minutes that participants wore the activity monitors and the number of activity counts for each minute (cpm) were calculated. The percentage of time spent in sedentary (MTI cpm: <800), light (MTI cpm: ≥800 and <3200), moderate (MTI cpm: ≥3200 and <8200), vigorous (MTI cpm: ≥8200), and moderate-to-vigorous ([MVPA] MTI cpm: ≥3200) physical activity during the 7 days was determined. These activity threshold counts have been validated in children using the MTI/CSA and are based on activity energy expenditure.32 The relationship between activity energy expenditure and activity counts is independent of age and gender and is, therefore, appropriate for assessing physical activity in children. The study was approved by the Children and Youth Institutional Review Board at the Women and Children’s Hospital of Buffalo.
Analytic Plan
Descriptive statistics were used to compute the mean and SD for family SES, child BMI percentile, parent BMI, child and parent age, height, weight, percentage overweight, and standardized BMI (z-BMI). Descriptive statistics for physical activity and motor proficiency were determined, and independent t tests were used to test for differences in descriptive characteristics, physical activity, and BOTMP standard score between boys and girls. Analysis of covariance was used to examine differences between boys and girls for each of the 14 items of the BOTMP controlling for child age and child z-BMI. Pearson product-moment correlations were computed to examine relationships between physical activity, motor proficiency, and child z-BMI, as well as CSAPPA and physical activity and motor proficiency. BOTMP standard scores were sorted in quartiles, and the differences in physical activity between the quartiles were tested using 1-way analysis of variance with linear contrasts to examine the distribution of the relationship between motor proficiency and physical activity. Hierarchical regression was then used to establish whether BOTMP standard scores accounted for a significant amount of incremental variance in child mean activity counts per minute after controlling for child gender, SES, televisions in the home, children in the home, child z-BMI, parent z-BMI, and CSAPPA score.
RESULTS
Sixty-nine children initially met the inclusion criteria and were given accelerometers to wear. Four children were excluded from the final data set: 1 child broke his arm during the study, another child participated in a school-based physical activity program during the study, and 2 children decided not to continue with the study after a few days of wearing the accelerometer. Therefore, a total of 65 children (31 boys and 34 girls) and parents (14 fathers and 51 mothers) were included in the final sample. Baseline descriptive statistics for parents and children are presented in Table 1. There were no statistically significant differences between boys and girls or between participating mothers and fathers for any of the descriptive characteristics. Physical activity data for the children are shown in Table 2. Children wore the accelerometer an average of 693.0 minutes (11.6 hours) per day, and reported sleeping an average of 590.4 minutes (9.8 hours) per day. The average amount of time that children spent in moderate and in vigorous physical activity per day was 25.8 minutes and 6.3 minutes, respectively. There were no differences in the activity data between boys and girls.
Descriptive Characteristics of Children and Parents
Physical Activity of Children as Measured by Accelerometry
The mean standardized score for the BOTMP was 55.5 ± 10.8 and is at approximately the 72nd percentile.28 There were no differences (P = .78) between overall BOTMP score for boys (55.9 ± 11.8; range: 24–73) and girls (55.2 ± 10.0; range: 35–75). When individual BOTMP items were examined, boys had faster times in running speed and agility (P = .033) and scored higher in throwing a ball at a target (P < .001) and response speed (P = .034) compared with girls. Girls sorted a greater number of shape cards than boys (P = .019).
There were significant associations between BOTMP standard score and activity counts per minute (r = 0.32; P = .011), percentage of time in sedentary physical activity (r = −0.31; P = .012), moderate physical activity (r = 0.33; P = .008), and MVPA (r = 0.30; P = .016) as shown in Table 3.There were significant negative correlations between z-BMI and activity counts per minute (r = −0.29; P = .02), percentage of time in sedentary activity (r = 0.28; P = .022), percentage of time in moderate physical activity (r = −0.36; P = .003), percentage of time in MVPA (r = −0.30; P = .014), and BOTMP standard score (r = −0.30; P = .015). There were no differences in the relationship among motor proficiency, z-BMI, and physical activity by child gender.
Correlations Between Physical Activity and Motor Proficiency and z-BMI
Three individual BOTMP items were related to physical activity: running speed and agility, broad jump, and copying overlapping pencils. The faster that children completed the running speed and agility task and the farther they jumped, the greater their average MTI counts per minute (speed and agility: r = −0.39, P = .001; broad jump: r = 0.39, P = .001) and percentage of time in moderate (speed and agility: r = −0.37, P = .002; broad jump: r = 0.41, P = .001), vigorous (speed and agility: r = −0.25, P = .048; broad jump: r = 0.30, P = .014), and moderate-to-vigorous (speed and agility: r = −0.36, P = .004; broad jump: r = 0.40, P = .001) physical activity and the less time they spent in sedentary activity (speed and agility: r = 0.36, P = .003; broad jump: r = −0.29, P = .019) compared with children who scored lower in these areas. Children who scored higher on the visual-motor task of copying a picture of overlapping pencils spent a greater percentage of time in moderate (r = 0.25; P = .047) and moderate-to-vigorous (r = 0.26; P = .037) physical activity than children who scored poorer on this task. There were no differences between boys and girls in the association of running speed and agility, broad jump, or copying pencils with physical or sedentary activity.
When motor proficiency was divided into quartiles to assess the distribution of the relationship between movement abilities and physical activity, significant differences were noted. Children in the greatest BOTMP standard score quartile had significantly (P < .01) greater MTI average activity and percentage of time in MVPA compared with children in the lower BOTMP quartiles (Fig 1). There were no significant differences in physical activity among children in the lower 3 quartiles.
Accelerometer counts per minute and MVPA (mean ± SEM) for quartiles of the BOTMP. Letters that are different indicate quartiles that are significantly (P < .02) different from each other on the basis of 1-way analysis of variance with linear contrasts.
There were no significant associations among CSAPPA total score or adequacy, predilection, and enjoyment factors and physical activity. There was a positive association between the predilection factor and BOTMP standard score (r = 0.40; P = .001), as well as CSAPPA total score and BOTMP standard score (r = 0.39; P = .001). The relationship between CSAPPA total score and BOTMP was different by child gender. CSAPPA total score was positively related to BOTMP standard score (r = 0.58; P = .001) for boys but not for girls (r = 0.20; P = .26).
Stepwise multiple hierarchical regression analysis showed that BOTMP standard score was independently associated with MTI activity counts per minute and explained 8.7% of the variance in activity after controlling for child gender, SES, televisions in the home, children in the home, child z-BMI, parent z-BMI, and CSAPPA score (Table 4).
Hierarchical Regression Model Predicting Child Mean Accelerometer CPM
DISCUSSION
The results of this study indicate that motor proficiency is positively associated with physical activity and negatively related to percentage of time in sedentary activity in children. When this relationship was examined by quartiles of motor abilities, children in the highest quartile of motor proficiency were the most physically active, with significantly greater MTI activity and percentage of time in MVPA compared with children in lower BOTMP quartiles.
Boys had significantly faster running speed and agility, threw a ball at a target more successfully, had greater response speed, and scored lower in sorting shape cards compared with girls. Previous research supports gender differences in motor skills, with boys performance in motor tasks of strength (running speed and long jump) and throwing a ball exceeding that of girls.33,34 Gender differences in motor proficiency can be explained by environmental influences, biological factors, or their interaction. Before puberty, the physical characteristics of boys and girls are similar, and environmental influences are more likely to explain gender differences in motor proficiency.33 The type of sports and games that boys and girls are drawn to participate in give them more opportunity to practice and refine their motor skills and may contribute to gender differences. For example, throwing and running games, such as baseball, are more popular among boys than girls.35,36 Despite the important role of the environment in motor skill development in childhood, some biological factors may also be present for certain skills, such as throwing. For example, compared with girls, boys have more midarm muscle tissue and a greater shoulder/hip ratio.33,37
We found that the faster that children completed the running speed and agility task and the farther they jumped, the more physically active and less sedentary they were. This suggests that running speed and agility and broad jump may be important to consider when examining the motor proficiency-physical activity relationship or when attempting to improve motor proficiency in youth. These movement skills may be fundamental tasks that promote increased strength and endurance for participation in active games and sports. In fact, children involved in extracurricular organized physical activities had better motor fitness as measured by a standing broad jump compared with children who indicated not participating in organized physical activities even after adjusting for age, height, body mass, and organized extracurricular physical activities.38 The correlation between copying a picture of overlapping pencils and physical activity suggests that visual-motor skills may be another important determinant of physical activity in youth in addition to gross motor proficiency. This finding is supported by previous cross-sectional research that found that children who were obese committed ∼50% more errors on a visual-motor drawing task compared with their normal weight peers.13
Some studies have demonstrated improvements in movement skills through interventions, such as specially programmed physical and health education for school children,39–41 but much of the research examining changes in motor proficiency after intervention strategies has been in children with disability or movement impairment conditions.42–46 Additional research is needed to investigate how much movement skills can be increased in youth without these conditions.
Although the children in this study were not overweight, children with greater z-BMI had significantly lower activity counts, less time in moderate and MVPA, more time in sedentary activity, and poorer motor proficiency. These results are consistent with previous findings that have reported negative associations between childhood obesity and physical activity,47 as well as childhood obesity and motor proficiency.13,14
Motor proficiency explained an additional 8.7% of the variance in physical activity after controlling for child gender, SES, televisions in the home, children in the home, child z-BMI, parent z-BMI, and CSAPPA score. This is larger than the 3% of the variance in time spent in organized physical activity explained by movement skills reported previously by Okely et al.8 Their lower value may be the result of physical activity being self-reported rather than objectively measured, a limited range of movement skills being tested, and that their study sample was adolescents rather than children.
Although the results of this and other research8,17 suggest that the association between physical activity and movement skills may be relatively weak to moderate, there may be a threshold of motor proficiency at which this relationship is most important. Our findings indicate that children in the greatest quartile of motor proficiency were the most physically active compared with children with lower levels of motor proficiency who had relatively similar levels of physical activity. Children with motor proficiency in the highest quartile had an average of 17.8 minutes per day more MVPA than youth in the lower quartiles, who averaged 27.9 minutes in MVPA. Because relatively little is known about the modifiable factors associated with physical activity in youth,3 and because even a small increase in physical activity can be beneficial for health,48 these data are particularly important for providing insight into motor proficiency as a determinant of physical activity in youth.
Children with lower self-perceptions of their abilities in physical activity have poorer coordination and report lower levels of physical activity than their peers.19,23 In our study, children who scored lower on the predilection factor of the CSAPPA had significantly poorer motor proficiency compared with children who scored higher in predilection. However, children's self-perception of physical activity was not associated with their measured physical activity. Other possible mediators of the relationship between motor proficiency and physical activity could be neurologic or physiologic in nature. Coordinated movement requires biomechanical and neuromuscular systems that provide activation, sequencing, timing, and scaling of muscle activity.49 Children with greater motor proficiency may, therefore, have more opportunities for and choose to participate in more varied physical activities, because they are better at activating and sequencing movement patterns. More efficient movement patterns may also result in less energy expenditure and lower levels of fatigue that may consequently lead to greater amounts and intensity of physical activity. Additional research is needed to more fully understand the psychosocial and neurophysiological mechanisms that may explain the association between physical activity and motor abilities.
This study, in combination with previous research,8,14,15,17,19 provides support for the relationship between motor proficiency and physical activity in youth. The MTI accelerometer has been validated in youth, and pediatric cut points that provide a valid measure of activity based on free-living activity were used. There are, however, several methodologic points to consider in interpreting these results. Because of the cross-sectional nature of this research, the direction of the relationship between physical activity and motor proficiency cannot be determined. The short form of the BOTMP was administered, but further research is needed to provide a more detailed assessment of how motor proficiency may be related to physical activity. Furthermore, because the BOTMP is a product-oriented assessment tool, the potential for accurately detecting specific aspects or components of motor skill difficulties and determining where improvement needs to occur is limited. To improve specific motor skills, a process oriented-test (eg, the Test of Gross Motor Development50) that breaks down skills, such as the run and broad jump, into specific observable components that can be taught and practiced would be appropriate. The accelerometer is a widely used tool to measure physical activity but may not assess all physical activities, such as swimming. Finally, the sample included primarily white children, and research is needed on diverse samples to establish the generalizability of the findings.
CONCLUSIONS
The findings from this study indicate that motor proficiency is positively associated with physical activity and inversely associated with sedentary activity. There may be a threshold of motor proficiency above which children may be the most physically active. Future research is needed to further examine the relationship between motor proficiency and physical activity. Longitudinal and intervention studies would provide information on the direction of this association. Research that examines motor proficiency among family members, such as parents and siblings, could lead to understanding possible familial factors that may interact to influence physical activity in youth. If motor proficiency is a determinant of physical activity, then strategies that increase movement skills in childhood may be an important target for helping promote increased physical activity and health in youth.
Acknowledgments
This research was funded in part by a clinical research grant from the American Physical Therapy Association (to Dr Wrotniak) and a Mark Diamond Research Fund from the University at Buffalo (to Dr Wrotniak).
We acknowledge and thank Drs James Roemmich and Mike Sill for consultation and advice during this research. We are also grateful to the families who participated in the study.
Footnotes
- Accepted July 10, 2006.
- Address correspondence to Brian H. Wrotniak, PT, PhD, The Children’s Hospital of Philadelphia and University of Pennsylvania School of Medicine, 3535 Market St, Room 1551, Philadelphia, PA 19104-4399. E-mail: wrotniak{at}email.chop.edu
The authors have indicated they have no financial relationships relevant to this article to disclose.
REFERENCES
- Copyright © 2006 by the American Academy of Pediatrics
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