Influence of thigh muscle strength and balance on hop length in one-legged hopping in children aged 7–12 years

Abstract

Background

Lower extremity muscular strength and balance are essential components in many motor performance skills. One-legged hopping is considered to be the most advanced jumping skill, because it requires greater muscle strength and better balance than other jumping skills. To what degree muscle strength and balance have significant influence on hop length in children is, however, unknown.

Objective

The purpose of the present study was to identify predictive factors for hop length in one-legged hopping. The main hypothesis was that both muscle strength of the thigh (quadriceps and hamstrings) and balance would be significant predictors in healthy children 7–12 years of age.

Method

341 girls and boys were included in the study. Hopping data was collected using the GAITRite system^®, muscle strength was tested isokinetically by a Cybex 6000 and one leg static balance was measured by the KAT 2000 system.

Results

Hop length and thigh muscle strength showed increased values from one age group to the next from 7 to 12 years of age, while static balance only showed minor fluctuation. Multiple regression analysis showed that thigh strength, static balance, age and gender all together explained 53.4% of the variance in hop length. Age, quadriceps strength and hamstrings strength made the largest contributions with Beta 0.32, p < 0.001, Beta 0.26, p = 0.001 and Beta 0.18, p = 0.003, respectively. Static balance and gender did not contribute significantly.

Conclusion

Of the measurements investigated in this study, age and thigh muscle strength are the strongest predictors for hop length in one-legged hopping skills in children.

Introduction

Fundamental movement skills (FMS) are elementary forms of movement, and acquisition and refinement of these basic movement patterns are during childhood integrated into specialized and more complex skills which are used in popular forms of adult physical activity [1], [2]. Learning to move and developing FMS in childhood are important and form the foundation for future levels of physical activity [3], [4].

Hopping on one leg is an advanced fundamental motor skill and an asymmetrical pattern of locomotion, and it evolves after upright walking is established [5]. As adults, we rarely use hopping on one leg to move around. Nevertheless, children should, in the process of becoming skilful movers, develop hopping skills during childhood [6]. Children use one-legged hopping in many play-game activities [7] and complex sports and dancing skills [6], [8]. To be able to hop on one leg, the child has to generate enough force to lift the body from the ground. Additionally, the child must absorb the weight of the body and maintain the balance on the small base of support that one leg provides before projecting the body weight in the air again [6].

Muscle strength and balance are essential components of many motor performances, in that a certain level of force and balance is needed to carry out the task. Different jumping tests are commonly used as indicators of muscle strength [2]. One-legged hopping is considered to be the most advanced jumping skill, because, in addition to controlled, rhythmical movements of both arms and legs, it requires greater strength and better balance than other jumping skills [8]. Hopping is also mentioned as a test of balance because this basic motor skill requires the body to be supported on one leg [2].

In light of the importance of muscular strength and balance in acquiring one-legged hopping, we wanted to investigate the exact influence that thigh muscle strength (the quadriceps and hamstrings muscles) and static balance have on this skill as a means of finding predictive values for hop length in children. A correlation between 0.64 and 0.78 has been found between thigh muscle strength and one-legged hopping in healthy young adults (mean age of 20 years) [9], [10]. However, no relationship has been found between static balance and one-legged hopping in young adults [10], and neither static nor dynamic balance has been shown to be predictive of mature skipping performance in children aged 4–14 years [11]. To our knowledge, no study has investigated the predictive values of thigh muscle strength and static balance on hop length in one-legged hopping in healthy children.

The purpose of this study was to identify predictive factors for hop length in one-legged hopping. The main hypothesis was that both thigh muscle strength and balance would be significant predictors in healthy children 7–12 years of age.