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

Abstract

The use of inertial measurement unit (IMU) has become popular in sports assessment. In the case of velocity-based training (VBT), there is a need to measure barbell velocity in each repetition. The use of IMUs may make the monitoring process easier; however, its validity and reliability should be established. Thus, this systematic review aimed to (1) identify and summarize studies that have examined the validity of wearable wireless IMUs for measuring barbell velocity and (2) identify and summarize studies that have examined the reliability of IMUs for measuring barbell velocity. A systematic review of Cochrane Library, EBSCO, PubMed, Scielo, Scopus, SPORTDiscus, and Web of Science databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. From the 161 studies initially identified, 22 were fully reviewed, and their outcome measures were extracted and analyzed. Among the eight different IMU models, seven can be considered valid and reliable for measuring barbell velocity. The great majority of IMUs used for measuring barbell velocity in linear trajectories are valid and reliable, and thus can be used by coaches for external load monitoring.

Validity and Effects of Placement of Velocity-Based Training Devices

“…Generally accepted are the parameters mean (v mean ) and peak (v peak ) concentric velocity (although mean propulsive velocity has also been proposed for fast, non-ballistic exercises [3]), which are usually obtained by linear position transducers (LPTs), inertial measurement units (IMUs), or some sort of optical system. Whereas Clemente et al [5] point out that devices employing IMUs are often most practical to use, Weakley et al [4] suggest that LPTs are Sports 2021, 9, 123 2 of 15 generally more accurate, although a strict distinction does not exist. Despite the abundance of largely similar studies in this area, new devices continue to become commercially available while existing devices evolve from one version to the next.…”

Wearables and Internet of Things (IoT) Technologies for Fitness Assessment: A Systematic Review

“…Internal loads are typically monitored using oxygen uptake, blood lactate concentration, heart rate, or rate of perceived exertion [ 18 ]. The external loads are typically monitored using global navigation satellite systems, inertial measurement units (IMU) [ 19 ], or linear transducers that provide measures related to distances covered at different speed thresholds, accelerations/decelerations and changes-of-direction [ 20 ]. Well-being is typically monitored using subjective scales related to fatigue, stress, quality of sleep, delayed onset muscle soreness, or mood.…”

Valid and Reliable Barbell Velocity Estimation Using an Inertial Measurement Unit

“…Velocity-based training (VBT) for strength and power conditioning has gained increasing interest in numerous sports [1]. Based on a strong relationship between the movement velocity and the relative load of the one repetition maximum (% 1RM), resistance training can be controlled by movement velocity [2,3].…”

“…In order to assess acute or training-induced changes of strength performance measures via VBT, an accurate and reliable measurement of the MCV is necessary [6]. As a minimal measurement error (reliability) is critically important to sports research [7], the validity and reliability of such sensors should be carefully examined [1]. Previous research underpins that linear position transducers provide high accuracy for an MCV assessment [8].…”