Force Plates Are Not Just for Labs: A Practical Guide for Coaches
Summary
Force plates have moved from laboratory exclusivity to field accessibility. Here's how to use them practically—what to measure, what it means, and how to make the investment pay off.
A decade ago, force plates were synonymous with biomechanics labs and research settings. Today, portable, robust, and increasingly affordable force plates are present in elite training facilities worldwide — and the coaches using them are discovering both their power and their complexity. This guide cuts through the complexity to the practical core.
What a Force Plate Measures
A force plate measures the ground reaction force (GRF) applied by the athlete to the plate during any contact with it. GRF has three components: vertical, anterior-posterior (front-to-back), and mediolateral (side-to-side). For most jump and weight-bearing tests, the vertical component is the primary variable of interest.
From the force-time record, a long list of derivative variables can be calculated:
- Jump height (from flight time or impulse-momentum method)
- Reactive strength index (jump height ÷ contact time)
- Peak force (maximum GRF during the push-off phase)
- Rate of force development (how quickly force rises — related to explosive capacity)
- Impulse (force × time — determines change in momentum and ultimately jump height)
- Asymmetry (on dual force plates — bilateral comparison of GRF in real time)
- Phase variables (eccentric deceleration impulse, propulsive phase duration)
Hori et al. (2009) demonstrated that force plates provide reliable estimates of jump performance variables when sampling frequency is ≥1000 Hz, which is the standard for modern portable units.
What to Actually Test
The CMJ is the most versatile and most researched force plate test. Run it weekly for neuromuscular readiness monitoring. Look at:
- Jump height: The primary trend indicator
- RSI (if contact time is available): Adds reactivity data
- Peak power: Derived from peak force × velocity; responds to training block type
- Countermovement depth: Changes in movement strategy indicate fatigue or injury
The Isometric Mid-Thigh Pull (IMTP) is the standard for measuring maximal force production. The athlete pulls against an immovable bar at a standardised joint angle. This gives you peak force and rate of force development — the "strength" end of the force-velocity relationship — without the skill demands of a 1RM test. McMahon et al. (2018) established IMTP as a reliable, sensitive measure of neuromuscular readiness.
What Not to Over-Interpret
The force plate generates so many variables that over-interpretation is the primary risk. If you are running 15 metrics per session and monitoring all of them, you will find "significant" changes by chance. Choose 3–4 primary variables before you start testing, define what constitutes a meaningful change for each athlete, and stick to those.
The most common trap is chasing phase variables (eccentric deceleration impulse, for example) with small samples and poor baselines. These variables require more data points for reliable interpretation than coaches typically collect. Jump height, RSI, and peak power are more robust as primary monitoring metrics.
Portable vs Fixed
Portable force plates (strain-gauge based) are adequate for jump testing and CMJ monitoring. They are less precise than laboratory fixed plates for detailed kinetic analysis but entirely sufficient for the most valuable use cases: athlete monitoring, return-to-sport assessment, and load management.
If you are using a portable plate, ensure the sampling frequency is at minimum 500 Hz (1000 Hz preferred), the plate is level and on a consistent surface, and the athlete's foot position is standardised across sessions.
Making the Investment Pay
A force plate that is tested weekly is worth ten times one that is tested quarterly. The value is in the trend, not the number. Build a testing routine that athletes understand, value, and can complete in under five minutes. The barrier to consistent force plate data is almost always the testing burden, not the technology.
References
Mark Fisher
Founder, Swift Performance
Mark Fisher is the founder of Swift Performance and has spent 30 years designing and building athlete testing equipment used by elite sport programmes and universities worldwide. He has worked alongside researchers and PhD candidates across biomechanics, sprint mechanics, and strength science — developing the hardware and software they use to collect and analyse performance data. His writing comes from three decades at the intersection of applied sport science and precision measurement technology.
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