The Reliability of the Seated Medicine Ball Throw as Assessed with Accelerometer Instrumentation

The Seated Medicine Ball Throw (SMBT) is low-risk, easy to perform, requires minimal equipment, and is a valid measure of upper body explosiveness. The Ballistic Ball™ (BB) medicine ball contains inertial sensors which estimate peak velocity, and transmits these values to an iPad™ app via Bluetooth™. This method of gathering data may be superior to using horizontal distance as there is less chance of confounding factors and it is easier to administer. The objective of this study was to evaluate the reliability of the BB peak velocity measurement in the SMBT. Twenty healthy, rested, recreationally-active, undergraduate students volunteered to participate in this study. After a standard dynamic warm-up, subjects were taught proper throwing technique. For familiarization, subjects performed repeated SMBTs with a 10 lb BB until horizontal distance thrown for 3 consecutive trials was within 0.25m. After 20 minutes of rest, subjects repeated the warm-up protocol, then performed 6 trials with the same 10 lb BB for which peak velocity was recorded. The test-retest reliability of these 6 trials was analyzed using intraclass correlations (ICC). The ICCs between consecutive trials ranged from 0.94 to 0.98. Peak velocity for trials 1-6 were: 3.85±1.14 m/s, 3.86±1.06 m/s, 3.94±1.22 m/s, 3.85±1.13 m/s, 3.95±1.21 m/s, 3.92±1.20 m/s, respectively. The high ICC values suggest excellent reliability of the peak velocity measurement from the BB device. The BB peak velocity as assessed during a SMBT is a reliable method for assessment of upper body explosiveness

The Reliability of the Seated Medicine Ball Throw for Distance

Measuring distance thrown during the Seated Medicine Ball Throw (SMBT) has been used frequently within the literature to quantify upper body explosiveness, due to the test being easy to learn, low-risk, and requiring minimal equipment. The reliability of distance thrown in the SMBT has not been broadly reported, nor have familiarization protocols been thoroughly documented. The purpose of this study is to assess the reliability of distance thrown during the SMBT as a representative measurement for upper body explosiveness in active, recreationally trained adults. Before testing, 20 subjects completed a dynamic warm-up. After learning proper technique, subjects were familiarized with the exercise by completing continuous trials using a 10 lb medicine ball, with 1 minute of rest between trials, until three consecutive throws within 0.25 m were achieved. Subjects rested 20 minutes, repeated the warm-up, and then completed 6 trials of the SMBT where distance of each throw was measured. Any trial in which technique deviated significantly from the instructions was repeated. Intraclass correlation coefficients (ICCs) were used to assess reliability between trials. Distances thrown for trials 1-6 were as follows: 3.43±0.99 m, 3.41±0.95 m, 3.48±1.00 m, 3.48±1.00 m, 3.46±1.03 m, and 3.54±1.05 m respectively. ICCs for consecutive trial pairs ranged from 0.97-0.99. These findings suggest that distance thrown is a reliable representative measure of upper body explosiveness in recreationally trained adults. The familiarization protocol used was sufficient for producing consistent performance