Method for Using IMU-Based Experimental Motion Data in BVH Format for Musculoskeletal Simulations via OpenSim.

Area of Science:

• Biomechanics
• Motion Capture Technology
• Musculoskeletal Modeling

Background:

• Biomechanical simulations require accurate kinematic data, often obtained via marker-based motion capture.
• Inertial Measurement Unit (IMU)-based systems offer flexible motion capture but lack standardized data transfer to simulation software like OpenSim.
• A gap exists in seamlessly integrating IMU-derived motion data into musculoskeletal modeling workflows.

Purpose of the Study:

• To develop and validate a method for transferring motion data from IMU systems (stored as BVH files) into OpenSim 4.4.
• To enable visualization and analysis of human motion within musculoskeletal models using IMU data.
• To overcome the limitation of non-universal IMU data transfer protocols.

Main Methods:

• Implementation of a virtual marker concept to map IMU data to musculoskeletal models.
• Utilizing Body, or BVH, file format for motion data storage and transfer.
• Conducting an experimental study with three participants to validate the developed method.

Main Results:

• Successful transfer of participant body dimensions from BVH files to a generic musculoskeletal model in OpenSim.
• Accurate transfer and application of motion data from BVH files to the musculoskeletal model within OpenSim 4.4.
• Demonstrated capability of the virtual marker method for IMU data integration.

Conclusions:

• The developed method effectively bridges the gap between IMU-based motion capture and OpenSim musculoskeletal simulations.
• This approach facilitates more accessible and flexible biomechanical analysis using IMU systems.
• The virtual marker technique provides a viable solution for integrating arbitrary IMU full-body measurement data into OpenSim.