Limit Of Agreement Analysis Of Seated Single-arm Shot-put Test Assessing Upper-body Physical Function In Athlete

PURPOSE: There is a significant body of work on shot-put field tests that target the upper extremities. The Seated Single-Arm Shot-Put Test (SSASPT) has been reported to be related to isokinetic strength; however, there is limited information about its relationship to isotonic muscle performance. Compared to our previous work in isokinetics, the advantage of isotonics is that the resistance pattern is more similar to the SSASPT. Unlike isokinetic testing, isotonic muscle performance involves acceleration and inertia, allowing for the computation of muscle power. METHODS: Twenty-six male and female athletes (mean age: 21 ± 2 years, height: 173 ± 11 cm, weight: 78 ± 16 kg, Tegner Activity Scale: 9 ± 1 arb., bone-free lean mass: 54 ± 12 kg, fat mass: 20 ± 9 kg, percent body fat: 27 ± 8%) volunteered to participate in this study. Participants underwent SSASPT and isotonic dynamometry testing in a randomized order. The isotonic testing included four concentric repetitions at resistances corresponding to 1 kg, 2 kg, and 3 kg medicine ball masses. Participants' dominant and non-dominant limb order was randomized. We aimed to determine the relationships among isotonic peak power, isotonic peak torque, isotonic peak velocity, and shot-put distance and to assess the limits of agreement (sensitivity) among limb symmetry indices (LSI) computed for these variables. RESULTS: There was a moderate correlation between SSASPT distances and isotonic peak velocity (r = 0.391 to 0.504). The Bland-Altman comparison method utilizing LSI among the tests showed no significant differences in isotonic peak power (P > 0.05; 95% confidence intervals ranged from -0.098 to 0.337, mean biases from 0.055 to 0.134), isotonic peak torque (P > 0.05; 95% confidence intervals ranged from -0.279 to 0.111, mean biases from -0.085 to -0.070), and isotonic peak velocity (P > 0.05; 95% confidence intervals ranged from -0.140 to 0.083, mean biases from -0.034 to 0.008) when compared to the SSASPT distances. CONCLUSION: The results suggest that isotonic testing of the SSASPT provides more accurate insights into the field test for assessing upper body physical function in athletes. Medicine ball weights of 1 kg, 2 kg, and 3 kg are sufficient for administering this test.