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Using Portable Force Plates to Assess Vertical Jump Performance: A Metrological Appraisal
François Raymond1, Benoit Lussier2, François Dugas3
1Institut National du Sport du Québec, 4141 Pierre de Coubertin, Montreal, QC H1V 3N7, Canada. fraymond@insquebec.org.
Sports (Basel, Switzerland)
|November 23, 2018
Summary
Portable force plates demonstrate good agreement and reliability for assessing countermovement jumps, making them suitable for clinical use. However, reliability of the flight time to contraction time ratio decreases on different floor surfaces.
Area of Science:
- Biomechanics
- Sports Science
- Human Movement Analysis
Background:
- Portable force plates are increasingly used for assessing countermovement jump (CMJ) performance.
- Verifying the metrological properties of these devices is crucial for accurate performance monitoring.
- Previous research has highlighted the need for validation against reference systems.
Purpose of the Study:
- To evaluate the metrological properties, specifically agreement and reliability, of portable force plates for CMJ assessment.
- To compare portable force plate measurements against a reference system.
- To determine the influence of different floor surfaces on measurement reliability.
Main Methods:
- A randomized crossover design was employed.
- Agreement analysis was conducted with 88 participants (38 males, 50 females).
- Reliability analysis involved 84 participants (37 males, 47 females) across various floor surfaces.
Main Results:
- Portable force plates showed trivial differences (ES < 0.20) and minimal mean bias (≤3.41%) compared to a reference system, indicating interchangeability.
- Absolute and relative reliability parameters were acceptable for clinical applications, even on different surfaces.
- The flight time to contraction time (FTCT) ratio exhibited questionable reliability (ICC = 0.49, CV = 26.72%) when tested on varying floor surfaces.
Conclusions:
- Portable force plates are a valid and reliable tool for assessing CMJ performance, suitable for clinical settings.
- Practitioners should exercise caution regarding floor surface consistency to ensure optimal reliability of CMJ metrics, particularly the FTCT ratio.
- Consistent installation on uniform surfaces is recommended for accurate CMJ monitoring and detecting genuine performance changes.
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