The Seated Medicine Ball Throw As A Test Of Upper Body Power In Older Adults

This is the authors' abstract. We don't add key points for this paper.

While muscle strength is an important fitness component for older adults, muscle power production may be a better indicator of functional ability. Unfortunately, few studies have evaluated the validity and reliability of field tests for upper body power in the older adult population. PURPOSE: This study‘s aim was to evaluate the validity and reliability of the seated medicine ball throw as a measure of upper body power in older adults. METHODS: Older adults (n=42; Age 72.4±5.2 years) completed 12 trials of a medicine ball (MB) throw over 2 testing days using two weights of MBs (1.5 Kg and 3.0 Kg). For each day and each MB, 3 trials were performed. From a seated position, subjects threw the MB as far as possible using a motion similar to a chest pass in basketball. Additionally, subjects completed 6 trials of an explosive modified push-up on a force plate (Kistler, 9281C) over 2 testing days. Push-up force data were collected at 1250 Hz and maximal vertical force output (Zmax) was recorded. Validity was assessed via a Pearson Product-Moment correlation coefficient (PPM) between MB throws and Zmax. Reliability of the MB throw was determined using PPMs, Intra-class Correlation Coefficients (ICC) and Bland-Altman Plots (BAP). RESULTS: The association between the medicine ball throws and the push-up test revealed a PPM of r=0.641 and r=0.614 for the 1.5 kg and 3.0 kg medicine balls respectively. PPM values for test-retest reliability of the 1.5kg and 3.0kg MB toss was r=0.967 and r=0.958, respectively. ICC values for test-retest reliability of the 1.5kg and 3.0kg MB toss was, R=0.994 and 0.989 for the 1.5 kg and 3.0 kg MB throws, respectively. BAPs revealed >95% of the differences were within ±2 standard deviations of the mean difference for both weights of MB throws. The ICC for the push-up test was R=0.969. For the modified push-up, reliability of Zmax was r=0.944 using PPM and R=0.969 using ICC. BAP showed 90% of the differences were within ±2 standard deviations of the mean difference. CONCLUSION: As a field test for upper body power for the older adult, the seated medicine ball throw appears to be highly reliable test. Its validity relative to the maximal force exerted during modified push-up is modest. However, for assessing and tracking upper body power in the older adult the medicine ball throw test is an inexpensive, repeatable measure.