Reliability of consumer applied wearable sensor for kinematic and kinetic analysis of overhand pitching

The PULSE workload monitor (PULSE) is a commercially available, wearable device that assesses upper extremity kinematics and kinetics during overhand pitching with three metrics to improve pitching performance. The purpose of this study was to determine the inter-tester and intra-tester reliability of the PULSE metrics when applied by a lay consumer versus trained researcher. A total of 14 healthy, adult male (age: 44.21 ± 17.54 years) baseball players were fitted with the PULSE under two application conditions, participant application and researcher application of the device. Each participant performed seven pitches of three pitch types, including fastball, curveball, and change-up, per application condition. The protocol was repeated during a second session one week later. Intraclass correlation coefficients (ICC) were determined to examine inter-tester and intra-tester reliability of the PULSE metrics between placement conditions and across sessions. For all pitch types, inter-tester reliability (ICC > 0.758) and intra-tester reliability (participant application: ICC > 0.710; researcher application: ICC > 0.890) were strong, indicating that the device is reliable when placed by a lay consumer. Findings suggest that PULSE may serve as an easily accessible, wearable device for reproducing pitching metrics that can inform consumer training.