Enriching Medicine Ball Throw with Anthropometric Information: An Alternative Assessment Method

Medicine ball throw (MBT) is a simple, fast and cost-effective field measurement method used to assess the explosive strength of the upper body strength based on throwing distance. Body weight and height have been identified as influencing factors of the traditional measure of distance thrown (MBT_T) with advantages for heavier and taller children. We designed three alternative indices taking into account body mass and height (MBT_A1 = MBT_T / (mass × height)), height-to-mass ratio (HMR) (MBT_A2 = MBT_T × HMR), or body mass index (BMI) (MBT_A3 = MBT_T / BMI). The validity of the four MBT indices was examined in linear mixed models (LMMs) and compared to achievements in other standard fitness tests (6-minute run, standing long jump, sideways jump, 4 × 10 m shuttle run, push-ups). The sample consisted of 821 Austrian primary school children, aged 7 to 10 years, from grades 2 and 3. The three anthropometrically enriched MBT_A yielded significantly better goodness of fit than MBT_T; MBT_A1 fitted best among the three MBT_A variants. When, alternatively, MBT measures were included as a covariate rather than a dependent variable in a second set of LMMs, MBT_A2 had the best goodness of fit. Results were replicated in a second sample of 173 secondary-school and 178 high-school students with standing long jump and push-up as physical fitness tasks. We recommend to enrich MBT_T with body weight and body height data to achieve a fair and realistic assessment of the explosive strength of the upper extremities.