Validity and reliability of the medicine ball throw for kindergarten children

The purpose of this study was to establish validity and reliability evidence for the medicine ball throw test for kindergarten students, an underrepresented group in the literature. The subjects were 105 students, 5-7 years old, BMI 17.44 +/- 3.17 kg x m(-2), 43% female and 57% male. Intraclass correlation coefficients (ICCs) were used to examine reliability, and Pearson correlation coefficients and a paired t-test were used to examine validity. To accomplish this, the kindergarten students completed the medicine ball throw test on two different days and the modified pull-up test, the "criterion" measure, on another day. For the medicine ball throw, each student sat on the floor before throwing the medicine ball forward like a chest pass three times. The medicine ball throw was highly reliable both within 1 day (ICCs = 0.93 and 0.94 for day 1 and day 2, respectively) and across 2 days (ICC = 0.88), with all reliability estimates over the acceptable level of 0.80. The medicine ball throw scores were positively related with height (r = 0.34) and weight (r = 0.34), and there was a significant difference between the 5-year-old group (mean +/- SD; 111.78 +/- 34.93) and the 6-year-old group (135.60 +/- 39.77), t = -3.23, p = 0.002, which supports correlational and known-difference evidence of validity for the medicine ball throw test. Even though no correlation was found between the medicine ball throw test and the modified pull-up test, r = -0.04, other forms of validity evidence (i.e., known-difference and correlational) were apparent. In conclusion, the medicine ball throw test seems to be a valid and reliable measure of upper-body strength for kindergarten children.