Changes in motor skill and fitness measures among children with high and low motor competence: A five-year longitudinal study

Summary

Children with low motor competence (LMC) are less able to participate fully in many sports and recreational activities typically enjoyed by their well-coordinated peers. Poor fitness outcomes have been reported for these children, although previous studies have not tracked these outcomes over time. In this study, 19 children (8 girls and 11 boys) with LMC aged between 5 and 7 years were matched by age and gender with 19 children with high motor competence (HMC). Six fitness (body composition and cardiovascular endurance) and motor skill (sprint run, standing broad jump and balance) measures were repeated for each group once a year for five years. For each year of the study, the LMC groups performed less well on all measures than the HMC groups. Changes over time were significantly different between groups for cardiovascular endurance, 50-m run and balance, but not for body composition, overhand throw or standing broad jump. Between the two groups, performances were significantly different for all measures, except body composition. These findings confirm the impact of LMC on fitness measures and skill performances over time.

Introduction

Children with motor difficulties are unable to participate successfully in many physical activities enjoyed by their well-coordinated peers. In addition, they have difficulty with everyday tasks important in home, school and social life.¹ As a consequence there may be a reduction in their perceived motor competence,² confidence and motivation to participate in physical activity,³ and, as a result, they withdraw from physical activity opportunities. Bouffard et al.⁴ describe this phenomenon as an ‘activity deficit’.

One of the many consequences of reduced activity is that fitness components, such as muscle strength and endurance, flexibility, cardiovascular endurance and anaerobic performance are compromised. While motor-coordination may confound some fitness measures, cross-sectional studies have shown that young children with low motor competence (LMC) are consistently outperformed by their well-coordinated peers.5, 6, 7, 8, 9, 10, 11 In a study of 85 children with LMC, performances on push-ups, a test of muscle strength and endurance, ranged between 0 and the 65th percentile rank.¹⁰ Hammond⁶ used the flexed arm-hang to measure upper limb strength in 17 children with LMC. Their performances ranged between the 5th and 62nd percentile rank. Extreme ranges of flexibility and inflexibility can be observed in this population.6, 10 Hyperflexibility reduces stability around the joint and may make controlled movement difficult, and hypoflexibility limits the range of movement of joints and therefore restricts movement. Reduced cardiovascular endurance was reported for children with LMC compared to well-coordinated children when completing a distance run over 8005, 6 and 1600 m.¹² O’Beirne et al.¹¹ compared 50-m run times (anaerobic performance) for 24 boys aged between 7 and 9 years with LMC to 24 coordinated controls. The boys with LMC were significantly slower than their peers. The recorded heart rates of children with LMC undertaking a multistage shuttle run reached a maximal level much earlier than a control group and consequently, these children were unable to sustain the task as long.¹³ The relationship between body composition and motor competence is less conclusive. Some studies have reported higher levels of overweight and obesity among children with LMC,6, 11, 14, 15 whereas others have only found significant difference among boys.¹⁶ Low fitness outcomes combined with inefficient motor patterns can contribute to early fatigue11, 13 and thereby, limit opportunities to develop motor skills through playground play, after-school sport and backyard activities.

What is not evident from studies investigating fitness and motor skills performances in children with LMC is whether the reported deficits, when compared to typically developing children, increase or decrease with time and maturity. Few studies have tracked motor skill and fitness variables over time in this population. If the activity deficit hypothesis is correct,⁴ children with poor motor competence would increasingly withdraw from physical activity opportunities, and the potential for relatively poorer outcome in fitness levels would increase. Where fitness measures were tracked over time in typically developing children, changes in physical activity level were only related to flexibility among girls and cardiovascular endurance among boys.¹⁷ However, where children with LMC have been tracked into adolescence, quite a few continue to experience motor problems, as well as educational, social and emotional difficulties.18, 19, 20

The purpose of this paper is to report the results of a subsample of children participating in a longitudinal study tracking fitness and skill levels of children attending a school in metropolitan Perth, Australia. A group of children with LMC were identified in the first year of the study through a motor screen undertaken by all children aged 5 to 7 years. Their fitness and motor skill results for five consecutive years are reported in comparison to a group of same-aged peers who were identified as having high motor competence (HMC).