New Perspectives on Analyzing and Interpreting Base Running Efficiency: An IMU Foot Pod Methodological Case Approach

Abstract

<jats:p>This article presents a practical framework for implementing, collecting, and interpreting inertial measurement unit (IMU) foot pod data to improve diagnostic understanding of baseball base running mechanics. Linear sprinting is used as a baseline, whereas the home-to-second-base sprint trial is used to examine how that capacity is expressed when athletes negotiate curvilinear running demands. The purpose is not to establish generalized performance outcomes, but to illustrate how IMU-derived spatiotemporal variables may be interpreted across successive base running segments in applied settings. Three competitive baseball players were selected from a larger dataset of n = 54 base runners tested using the same protocol with distinct home-to-second-base performance profiles as follows: the fastest case (Player X), an intermediate case (Player Y), and the slowest case (Player Z) were selected based on total home-to-second-base time. The cases were selected purposively to demonstrate the application of the IMU interpretation framework, including ground contact time (GCT), stride length (SL), push-off acceleration, and impact acceleration. Particular emphasis is placed on how curvilinear demands alter inside- and outside-foot function, and how segment-to-segment comparisons may help practitioners identify phases in which base runners maintain, reorganize, or lose mechanical efficiency. Compared with broader velocity-based approaches, the IMU framework provides complementary step-level information that may help practitioners generate hypotheses about how base runners organize movement across linear and curvilinear segments. These examples are intended to demonstrate a workflow for applied interpretation rather than to establish causal mechanisms. As a result, IMU foot pod analysis may offer practitioners a structured and portable method for interpreting curvilinear sprint mechanics, yet these case examples should be understood as descriptive rather than prescriptive.</jats:p>