Effects of age, sex and activity level on counter‐movement jump performance in children and adolescents

Abstract

The aim of this study was to investigate counter-movement jump performance and its reliability in children and adolescents with respect to age, sex and activity level. We tested 1835 children and adolescents aged between 4 and 17 years. All participants performed three counter-movement jumps on a force platform with arms akimbo. The participants were divided into six age groups and subdivided by sex within each group, to analyse age and sex effects. Subsequently, jumping performance of active and sedentary participants was compared. Jump height was calculated and the highest jump out of three was used for the calculations of peak force and peak rate of force development. Variability of all parameters was quantified using the coefficient of variation over all jumps. Jump height increased significantly with increasing age while peak rate of force development decreased. Peak force was similar for all age groups. Jump height was significantly higher in male participants and peak force and peak rate of force development was significantly lower in male participants. Variability of jump height and peak force decreased significantly with increasing age leading to reliable data above the age of 10 years. Peak rate of force development showed a high variability and, therefore, should be interpreted with caution. This could be useful information for coaches as they need to know from which age onwards the counter-movement jump is applicable in performance diagnostics and which parameters are sensible for interpretation. Finally, the present study provides data to be used as normative references.

Developing a Criterion Method for Assessing Countermovement Jump Variables in Children Aged 7 to 11 Years

“…Neuromuscular performance CMJ variables such as, jump height (JH), rate of force development (RFD), peak force (Fmax) and most notably lower body instantaneous peak mechanical power output (PPO) has been closely associated with a wide variety of important factors in child populations such as measuring the effects overweight and obesity (Bovet, Auguste, & Burdette, 2007), used as an indicator of bone strength and health (Schoenau & Fricke, 2008;Weeks, Young, & Beck, 2008), used to monitor maturation status (Beunen, 1988;Lloyd, Oliver, Faigenbaum, Myer, & De Ste Croix, 2014;Malina, Bouchard, & Bar-Or, 2005) and used as measure coordination (Clark, Phillips, & R, 1989;Korff, Horne, Cullen, & Blazevich, 2009), which could be used to identify children with motor disorders such as children with developmental coordination disorders (DCD). Though the interpretation of many of these studies utilising CMJs as a measure of lower body neuromuscular performance in children (PPO, RFD and JH) are confounded by methodological limitations, such as the lack of key specification necessary to determine their validity Focke et al, 2013;Gabel, Macdonald, Nettlefold, Race, & McKay, 2016;Sumnik et al, 2013). Consequently, this has produced a number of studies with unclear results (Duncan, Hankey, Lyons, James, & Nevill, 2013;Focke et al, 2013;Gabel et al, 2016;Knudson, 2009;Raffalt, Alkjaer, & Simonsen, 2016a;Sumnik et al, 2013; M. J. D. Taylor, Cohen, Voss, & Sandercock, 2010).…”

“…Though the interpretation of many of these studies utilising CMJs as a measure of lower body neuromuscular performance in children (PPO, RFD and JH) are confounded by methodological limitations, such as the lack of key specification necessary to determine their validity Focke et al, 2013;Gabel, Macdonald, Nettlefold, Race, & McKay, 2016;Sumnik et al, 2013). Consequently, this has produced a number of studies with unclear results (Duncan, Hankey, Lyons, James, & Nevill, 2013;Focke et al, 2013;Gabel et al, 2016;Knudson, 2009;Raffalt, Alkjaer, & Simonsen, 2016a;Sumnik et al, 2013; M. J. D. Taylor, Cohen, Voss, & Sandercock, 2010). When assessing human movement or collecting any type of data it is critical that the data collected is valid and reliable.…”

“…Therefore, it is essential that primary children (aged 7 to 11 years) have a valid means of measuring countermovement jump variables or a means of estimating these variables as none currently exist or have been developed for child populations. For example, if researchers collect the CMJ variable PPO without first employing a criterion method, the reported results will be unclear as errors will occur when deriving the output variable or the equipment used may not meet the required specification to collect meaningful data in children Focke et al, 2013;Gabel et al, 2016;Sumnik et al, 2013). Furthermore, if adult developed regression equations are used to estimate PPO in children as FP are expensive and limited to organisations with large budgets , the lower body mass in children coupled with the higher negative intercept values from adult models will result in a misrepresentation of the actual power values generated in the child and in some cases attain values that are biologically and biomechanically implausible .…”

“…Furthermore, the discrepancies found within the findings of CMJ variables in child populations may be a result of the interchangeable use of absolute values and values that account for body size such as normalising and allometric scaling. For example, a study by Focke et al (2013) investigated the effects of age, sex and activity level on CMJ performance in children and adolescents. The results showed that absolute jump height (JH) increased significantly with age, whereas when JH was normalised to body height, the influence of age was ameliorated.…”

“…Although significant differences may be anticipated, it remains to be reported which parameters differ and the magnitude of difference. Indeed only six previous studies have investigated CMJ F/T history variables via a FP Focke et al, 2013;Gabel et al, 2016;Sumnik et al, 2013), with only three study directly comparing children and young adults (Gabel et al, 2016;Raffalt et al, 2016bRaffalt et al, , 2016a. However, the findings of these studies remain largely unclear, due to a number of CMJ variables reported with limited to no information with regards how start time (ts) or other important specifications are determined to prior to calculation of the CMJ variables.…”