Validity of a novel inertial measurement unit to track barbell velocity

The objective of this work is to analyze the reliability and validity of the new inertial measurement unit (IMU) PUSHTM Band 2.0 to measure barbell velocity. Six healthy males (24.83±3.71years; 69.88±8.36kg; 175.92±4.5cm) participated in this study and performed several sets on the bench press. Barbell concentric mean (MV) and peak (PV) velocity were recorded with a LT and the IMU. Pearson correlation coefficient shows a very high relationship for MV (r = 0.97; SEE: 0.08 m/s; 95%CI: 0.95-0.98; p< 0.001) and PV (r = 0.97; SEE: 0.13 m/s; 95%CI: 0.96-0.98; p< 0.001). There was a very high agreement for the values of MV and PV (MV: ICC = 0.945, CI = 0.834–0.974, α = 0.981; PV: ICC = 0.926, CI = 0.708–0.969, α = 0.977). Paired sample t-test revealed systematic bias for MV (p< 0.001; mean difference between instruments = 0.06 ± 0.09 m/s) and PV (p< 0.001; mean difference between instruments = 0.15 ± 0.18 m/s). Bland-Altman plots showed almost trivial and moderate relationships for MV (r2 = 0.1) and PV (r2 = 0.37). In conclusion, the PUSHTM Band 2.0 was proven to be a valid alternative for measuring barbell velocity in the bench press.