Validation of Inertial Sensor to Measure Barbell Kinematics across a Spectrum of Loading Conditions

Abstract

<jats:p>The aim of this study was to evaluate the level of agreement in measuring back squat kinematics between an inertial measurement unit (IMU) and a 3D motion capture system (3DMOCAP). Kinematic variables included concentric peak velocity (CPV), concentric mean velocity (CMV), eccentric peak velocity (EPV), eccentric mean velocity (EMV), mean propulsive velocity (MPV), and POP-100: a proprietary variable. Sixteen resistance-trained males performed an incrementally loaded one repetition maximum (1RM) squat protocol. A series of Pearson correlations, 2 × 4 RM ANOVA, Cohen’s d effect size differences, coefficient of variation (CV), and standard error of the estimate (SEE) were calculated. A large relationship existed for all variables between devices (r = 0.78–0.95). Between-device agreement for CPV worsened beyond 60% 1RM. The remaining variables were in agreement between devices with trivial effect size differences and similar CV magnitudes. These results support the use of the IMU, regardless of relative intensity, when measuring EMV, EPV, MPV, and POP-100. However, practitioners should carefully select kinematic variables of interest when using the present IMU device for velocity-based training (VBT), as certain measurements (e.g., CMV, CPV) do not possess practically acceptable reliability or accuracy. Finally, the IMU device exhibited considerable practical data collection concerns, as one participant was completely excluded and 13% of the remaining attempts displayed obvious internal error.</jats:p>

Validity and Reliability of the Inertial Measurement Unit for Barbell Velocity Assessments: A Systematic Review

“…Twenty-one of the included articles tested validity of the IMU [ 23 , 24 , 27 , 34 , 46 , 48 , 49 , 56 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ]. Nineteen of the included articles tested the reliability of the IMU [ 23 , 24 , 27 , 34 , 46 , 48 , 49 , 56 , 57 , 58 , 60 , 61 , 62 , 64 , 65 , 66 , 67 , 68 , 69 ]. Six of the included articles compared the IMU with linear transducers [ 23 , 27 , 32 , 48 , 62 , 68 ].…”

“…Among the included studies, 10 tested the back squat [ 23 , 34 , 46 , 56 , 57 , 58 , 62 , 63 , 65 , 68 ]; 9 the bench press [ 1 , 23 , 24 , 34 , 49 , 58 , 64 , 66 , 69 ], 1 the hip thrust [ 34 ]; 1 the bench throw [ 58 ], 1 the prone bench pull [ 23 ]; 2 the counter movement jump [ 60 , 67 ]; 1 the power snatch, clean, jerk [ 61 ]; and 1 the hexagonal barbell deadlift [ 48 ].…”

“…Information of the reliability levels obtained in the included studies can be found in Table 5 . Generally, the Barsensei model was the only model not being considered reliable for more than one article [ 27 , 46 ]. The remaining models presented evidence of reliability.…”

“…Overall, eight different IMU models were tested for validity. The reviewed studies were conducted using the BarSensei [ 27 , 46 ], the Gyko [ 49 ], the Myotest [ 56 , 58 , 59 , 65 , 67 , 69 ], the PUSH Band [ 23 , 24 , 48 , 54 , 64 , 66 ], the Wimu Real Track [ 6 , 60 , 62 , 68 ], the PASCO [ 61 , 70 ], and the Rehagait [ 63 ]. Four studies [ 27 , 46 , 60 , 67 ] reported a lack of validity of IMU equipment.…”

“…On the basis of the importance of confirming the validity and reliability of IMU devices, different original studies have reported the results for different models in the sports sciences community [ 46 , 47 , 48 , 49 ]. Naturally, different experimental protocols have led to different results, and not all of the models are covered in the same conditions.…”