Key Metrics
Key metrics are values derived from force data, shown together in the Key Metrics databox.
This article is about the Key Metrics data box. Version 26.2 added a separate Key Metrics column in the analysis view: see The Key Metrics Column .
This article covers the new key metrics databox introduced in version 10.0. Although released in version 10.0 this article covers functionality available in 10.2 which may be different from earlier versions.
Available in version: 10.2 and up.
Applicable to: Motion Catalyst
Required hardware: Force plate(s) / Motion Plate / Dual Motion Plate. The golf timing metrics described below are the exception: they are read from the bookmark positions and need no force plate.
Software license that supports key metrics.
What are key metrics?
The key metrics are derived from force data and analysis is performed on this data.
Different activities have different key metrics, and not all activities have the same amount of key metrics available.
What activities are key metrics available for?
Key metrics are available for the following activities in Motion Catalyst:
Counter Movement Jump
Dynamic Balance
Isometric Mid-Thigh Pull
Plyo-push up
Push Up
Repeated Hops
Static Balance
Squat Jump
Upper Body Plank
We are looking to expand this list and support other sports in the future.
Golf swings have their own set of timing metrics, described below. These do not need a force plate.
Golf timing metrics
Three timing metrics are available for golf swings. They are worked out from where the swing phase bookmarks sit on the timeline, so no force plate is involved and they are available on camera-only recordings.
| Metric | What it measures | Unit |
|---|---|---|
| Tempo Ratio | Backswing time divided by downswing time, in other words Start of Take Away to Top of Swing against Top of Swing to Impact | Ratio (no unit) |
| Transition Duration | Time from Top of Swing to Early Downswing | Milliseconds |
| Release Timing | Time from Impact to Release | Milliseconds |
Tempo Ratio has a target range of 2.0 to 3.0. The classic reference is a 3:1 tempo, so a value of 3.0 means the backswing took three times as long as the downswing.
Tempo Ratio only needs Start of Take Away, Top of Swing and Impact, so it works on older golf recordings too. Transition Duration and Release Timing read the Early Downswing and Release bookmarks, which only exist on recordings with the ten detected swing phases. On a recording without them, those two metrics report that a bookmark they need is missing.
These metrics are only as accurate as the bookmark positions they are read from. If the bookmarks are in the wrong place, so are the numbers. Letting the software place them from motion capture is the most reliable option: see Golf swing phase detection .
The Key Metrics data box
Key metrics is a new databox that shows key values from valuable points in an activity.
It’s possible to customize which key metrics are shown by selecting each “tile” and selecting from the key metrics drop-down menu. These selections will be remembered for the next recording you open, similar to how it remembers which databox is shown.
Presentation options
It’s possible to change the layout of the Key Metrics databox from 4, 6 or 8 metrics.
Reducing the amount of metrics can be helpful to reduce clutter and improve visibility.
Export all key metrics (TSV)
The Key Metrics databox also supports exporting all of the available key metrics to a tsv (tab separated values) file directly from the databox itself.
Key metrics are missing for this recording
In some cases key metrics aren’t available for a specific activity or the recorded activity, clicking “More info” can reveal more information about why key metrics are unavailable.
Common causes:
Not performing the activity properly / according to protocol.
Moving too much before performing the activity.
Incorrect body weight configuration.
Bad force plate calibration (try to calibrate / zero the force plates).
Improper force plate setup.
I don’t have the Key Metrics data box
Key metrics is only available for Motion Catalyst and for a select number of activities.
Possible causes:
License doesn’t support key metrics.
Not using Motion Catalyst / no license for Motion Catalyst.
Activity or sport doesn’t support key metrics.