CSP Elite Baseball Development Podcast: The Next Generation of Biomechanics with Scott Selbie

How many cameras are needed to produce consistent markerless motion-capture data, and how does the size of the capture space affect that decision? A 2026 study published in the Journal of Biomechanics examined how reducing an 18-camera Theia3D setup to 12 or six cameras affected kinematics during walking, running and countermovement jumping in two capture volumes of differing size. Across 10 healthy adults, mean differences remained below 1.7° for walking, 4.1° for running and 2.6° for jumping. The findings suggest that the combined effects of camera placement and capture-volume size on consistent multi-angle segment visibility can be just as important as camera count when designing a markerless motion-capture setup.

Researchers at McMaster University and St. Joseph’s Healthcare Hamilton combined markerless motion capture, patient-reported outcomes, and free-living wearable data to examine mobility in 56 patients awaiting knee arthroplasty. The analysis identified two distinct mobility profiles. However, substantial variation within the higher-functioning group showed that how patients perceive their mobility, perform in a clinic, and move in daily life do not always align.

This article is the second in a miniseries exploring what motion capture can show beyond radar, ball data, and standard video. In this installment, Dean compares pulldowns with mound throws to examine whether the additional forward momentum athletes create during pulldowns travels up the kinetic chain and changes how the throwing arm moves.