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Inertial Measurement Unit Sensor-to-Segment Calibration Comparison for Sport-Specific Motion Analysis
Mitchell Ekdahl1, Alex Loewen1, Ashley Erdman1
1Scottish Rite for Children, Frisco, TX 75034, USA.
Sensors (Basel, Switzerland)
|September 28, 2023
Summary
Wearable inertial measurement units (IMUs) offer a viable alternative to optical motion capture for measuring joint angles in dynamic sports movements. Selecting appropriate sensor-to-segment calibration methods is crucial for accurate lower extremity range of motion (ROM) assessment.
Area of Science:
- Biomechanics
- Sports Science
- Wearable Technology
Background:
- Optical motion capture is the gold standard for joint angle measurement.
- Wearable inertial measurement units (IMUs) present a more accessible alternative.
- IMUs require precise sensor-to-segment calibration for accurate data collection.
Purpose of the Study:
- To evaluate existing sensor-to-segment calibration methods for IMUs.
- To compare IMU-derived lower extremity range of motion (ROM) with optical motion capture during dynamic sports movements.
- To determine the most accurate calibration methods for specific joints and tasks.
Main Methods:
- Seven distinct sensor-to-segment calibration methods were assessed.
- Lower extremity ROM was measured using IMUs and compared against an optical motion capture system.
- Data were collected during various highly dynamic, sports-related movements.
Main Results:
- Accuracy of IMU ROM measurements varied significantly across different calibration methods, joints, and tasks.
- Absolute mean differences between IMU and optical capture ranged from <0.1° to 24.1°.
- Fewer significant differences were found for pelvic measurements compared to hip, knee, or ankle.
- For each task, at least one calibration method yielded non-significant ROM differences for most variables.
Conclusions:
- IMUs show potential as a practical alternative to optical motion capture for sport-specific lower extremity ROM assessment.
- The choice of sensor-to-segment calibration method is critical and should be tailored to the specific application, tasks, and ROM variables of interest.
