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Swimming Velocity Analysis Using Wearable Inertial Sensors and Speedometer: A Comparative Study
Leandro Vieira1, Mário J Costa1, Catarina C Santos1,2
1Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, 4200-450 Porto, Portugal.
Bioengineering (Basel, Switzerland)
|August 29, 2024
Summary
Inertial measurement units (IMUs) do not accurately measure breaststroke swimming velocity compared to traditional speedometers. IMUs show lower velocity values and significant bias, making them unsuitable for evaluating intracycle velocity variations.
Area of Science:
- Sports Science
- Biomechanics
- Swimming Performance Analysis
Background:
- Traditional speedometers are used for swimming velocity but have limitations.
- Inertial measurement units (IMUs) are emerging as potential alternatives for motion analysis.
Purpose of the Study:
- To compare velocity data from an IMU and a speedometer during maximal effort breaststroke sprints.
- To assess the agreement between IMU and speedometer measurements for swimming velocity.
Main Methods:
- Sixteen swimmers performed 4x25m breaststroke sprints.
- An IMU was worn on the sacrum, and a speedometer was placed on the lumbar region.
- Statistical parametric mapping and Bland-Altman plots analyzed velocity data.
Main Results:
- IMUs and speedometers showed dissimilar velocity patterns during breaststroke.
- IMU-measured velocities were significantly lower than speedometer measurements (p < 0.001).
- Bland-Altman analysis revealed substantial bias in coefficient of variation and intracycle velocity variation.
Conclusions:
- IMUs and speedometers are not interchangeable for assessing swimming velocity.
- Current IMU technology is not a substitute for speedometers in evaluating intracycle velocity variations in breaststroke.
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