How PLNU × Padres Captures Game-Speed Swing Data With Theia3D

Summary

The PLNU × Padres Biomechanics Lab set out to measure swings the way athletes actually perform them—at full intent, in real training environments. With Theia3D, the team now captures synchronized bat and body mechanics without markers, sensors, or workflow disruption. Early results reveal what game-speed swings truly look like and why this shift is reshaping both research and player development.

Overview

The PLNU × Padres Biomechanics Lab is a joint facility between Point Loma Nazarene University and the San Diego Padres. The lab is directed by Dr. Arnel Aguinaldo, an internationally recognized researcher in baseball biomechanics, and home to some of the most advanced motion analysis research in professional sports.

Their challenge: capture full-body biomechanics and bat tracking data simultaneously, at game intensity, without disrupting the swing or adding to athlete preparation time. With Theia3D, they've solved it.

The Challenge: Capturing Game-Speed Swings Without Compromise

Baseball batting is a high-speed, explosive movement. To understand it, researchers need to capture:

Whole-body kinematics – pelvis rotation, trunk sequencing, shoulder mechanics
Bat movement data – bat speed, path, and orientation through the hitting zone

Traditional systems require markers and extensive setup, which disrupts the natural feel of the swing and limits ecological validity. Until recently, there wasn’t a system that could provide both body and bat data at full intensity, in a real batting environment, without compromising the swing.

The Solution: Markerless Body Tracking + Bat Tracking

The PLNU × Padres Lab implemented Theia3D alongside integrated bat tracking to capture synchronized body and bat biomechanics in a single session setup.

Key workflow features:

No markers or wearables on the athlete
Athletes swing in game-condition clothing and with game bats
Full 3D skeleton capture plus synchronized bat position and orientation
Automatic, batch-ready data output for scalable research workflows

“Theia’s markerless technology represents a breakthrough in how we capture and analyze swing mechanics. It removes the barriers of traditional setups, letting us gather quality swing data directly from the field or the cage. That’s a game changer for both research and applied development.”

Dr. Arnel Aguinaldo, Director, PLNU × Padres Biomechanics Lab

Early Insights: What Full-Speed Swing Data Reveals

With Theia3D capturing full-speed swings, the PLNU × Padres team is beginning to establish biomechanical benchmarks that weren’t previously available. Early observations include:

Natural swing kinematics differ measurably from swings performed in traditional marker setups
Bat path and body sequencing relationships are more variable than previously assumed under controlled conditions
Individual movement signatures are consistent across sessions, suggesting reliability for longitudinal research tracking

A New Foundation for Swing Research and Development

The PLNU × Padres Lab is using this data to build normative benchmarks across athlete groups, connecting whole-body movement to bat outcomes at game intensity. This work is laying the groundwork for scalable, ecologically valid swing assessment in both research and applied settings.

Want to learn how Theia3D + bat tracking can support your program? Book a demo to see it in action.

Recent Posts

A Major Research Milestone for Theia3D

More than 50 independent, peer-reviewed research publications now cite, evaluate or review Theia3D across domains including gait, sports performance, postural control, upper-extremity movement and other biomechanics applications. These publications are available in world-leading journals including Journal of Biomechanics, Journal of Applied Biomechanics, Gait & Posture and Clinical Biomechanics. Together, they represent a growing body of evidence across different movements, populations and environments, reinforcing Theia3D’s position as the most extensively validated markerless motion capture system.

Beyond The Radar Gun: How Dean Jackson uses Theia3D For Incremental Velocity Analysis

This article is a first in a miniseries that breaks down what motion capture can show beyond radar, ball data, and standard video. In this first installment, Dean breaks down how he uses Incremental Velocity Analysis, or IVA, to study what changes biomechanically as pitchers move closer and closer to max output.

New Research on Theia3D: Comparing Markerless and Marker-Based Shoulder Kinematics Across Full Arm Range of Motion

A 2025 study published in the Journal of Biomechanics compared shoulder kinematics measured with Theia3D markerless motion capture against gold-standard marker-based motion capture across full arm ranges of motion. The results show strong agreement for many movements, particularly in the coronal plane, while also highlighting where caution is still required, especially at the extremes of ranges of motion and in transverse-plane rotations.