Looking Beyond the Number of Repetitions: An Observational Cross-Sectional Study on Calf Raise Test Outcomes in Children Aged 10-17 Years.

Aims: The calf raise test (CRT) assesses plantarflexor strength and endurance, but normative data for children are scarce. Furthermore, contradictions exist on which factors are associated with total repetitions, with repetitions being the only metric considered. We quantified three of the main CRT outcomes (repetitions, total work, and peak height) in children 10-17 years and explored their relationship with various factors.

Methods: Healthy children (n = 165, 50.3% female) completed single-legged calf raises on a 10° incline, once on each leg. Test outcomes were extracted using the valid and reliable Calf Raise application.

Results: CRT outcomes were not significantly different between legs (p ≥ .19). The only covariates significantly associated with outcomes based on stepwise quantile regressions were body mass index centile for repetitions, meeting physical activity recommendations for total work and peak height, and age for total work. Outcomes did not significantly differ based on sex or maturation. Median values were around 26 for repetitions, 640-1460 J for total work (age dependent), and 10.1 cm for peak height for children meeting physical activity recommendations.

Conclusion: Children who were older, had lower body mass indices, and were more active exhibited superior CRT outcomes. Meeting physical activity recommendations appears beneficial for plantarflexor function and should continue to be prioritized in children.