Analyze
Body
The 33-point skeleton, your joint angles on every frame and the charts of a whole swing in the Body tab.
The Body tab draws a skeleton on your body and gives you your joint angles on the frame you’re looking at. It can also follow a whole swing and chart how your arms and legs move. Everything runs on your computer.
Turn tracking on#
Turn on Body tracking in the tab, with the skeleton button on the tool rail or with S. The first time, the model downloads (a few seconds).
The options#
- Racket hand: right or left. It comes from the current player.
- Angles: On screen shows angles as they appear in the video; 3D est. estimates the true angles, whatever the camera position (noisier).
- Model: Fast, Balanced or Accurate. Accurate takes longer per frame.
- Angle labels and Racket-hand trail: the numbers on the video and the path your hand travels.
This frame#
The numbers for the frame you’re looking at:
- Elbow, shoulder, hip and knee, right and left, in degrees. 180° is a straight joint; the smaller the number, the more bent.
- Trunk lean: how far your trunk leans from vertical.
- Shoulder tilt: how far the line of your shoulders tilts.
- Shoulder–hip separation: how far your shoulders are turned relative to your hips, seen from above (3D estimate). It’s the “coil” of your preparation.
- Racket-hand speed: how fast your racket hand is moving.
When a joint is hidden, the app says so: its angle is less reliable.
Analyze a swing#
Analyze a swing tracks every frame of the In–Out loop (or the 2 seconds around the playhead) and charts how your angles change through the swing, with your hand speed and its peak.
- Pick the stroke. Set the start with I and the end with O, or put the playhead at contact.
- Press the button. It says how many seconds and frames it will track.
- Read the charts. Hover to see each moment; Table shows the numbers and Export CSV downloads them for a spreadsheet.
Hand speed is measured in the picture; to see it in km/h, calibrate the scale with a court line (see Playback and tools).