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visual3d:tutorials:events:kinematic_event_detection

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Kinematic Event Detection

Assessing Different Kinematic Methods of Structuring Gait

This tutorial is based on a research project presented at the Ontario Biomechanics Conference (OBC) 2025 titled “Assessing Different Kinematic Methods of Structuring Gait”.

The goal of this tutorial is to help users replicate the research process and understand ho to structure gait cycles without relying on kinetic data (e.g. from force plates or instrumented treadmills). Instead, we will use kinematic data and implement several established event detection algorithms using Visual3D.

This tutorial is intended for users who either do not have access to lab-grade kinetic instrumentation, or see this equipment as unideal for their environment- in the case of a field-based or markerless system.

Objectives

  • Introduce and implement kinematic-based gait event detection methods from peer-reviewed literature.
  • Provide a step-by-step approach to structuring gait cycles in Visual3D.
  • Compare the derived cycles to kinetic-based baseline cycle.
  • Use downloadable data, Visual3D pipelines, and batch scripting workflows in order to simulate the process of this investigation.

Background and Rationale

Traditionally, gait cycle events such as Heel Strike (HS) and Toe Off (TO) are defined using force thresholds derived from ground reaction force (GRF) data. This method is reliable but dependent on lab based equipment.

Kinematic methods detect HS and TO using joint angles, segment velocities, or spatial relationships between anatomical markers. Although these methods are not perfect, they are crucial for field-based studies, clinical gait analysis, and wearable-only workflows.

In our project, we evaluated the following kinematic event detection methods:

Each method identifies gait events based on unique kinematic patterns, such as:

  • Local minima/maxima in foot marker trajectories.
  • Peak knee flexion or extension.
  • Spatial relationship between foot and hip joint centers.

Dataset Description

Participants: 42 healthy adults (24 younger, 18 older)

Trials: 5-8 treadmill walking trials per participant, increasing speed per trial.

Collected Data: Marker trajectories and kinetic data from an instrumented treadmill.

Processing Software: Visual3D

  • Only left-side gait events were analyzed.
  • Data was pre-processed to extract joint angles, segment positions and other features required for each algorithm.
visual3d/tutorials/events/kinematic_event_detection.1748451262.txt.gz · Last modified: 2025/05/28 16:54 by wikisysop