Javelin Analysis
Block-leg and release mechanics from a side clip: block-to-release timing, block leg, trunk tilt, hip-shoulder separation, elbow height and release angle.
How far has this tool been checked?
The measurements were checked against computer-drawn athletes whose true answers are known exactly. That shows the arithmetic and the event rules are right under clean, controlled conditions. It does not measure how well the body-tracking model sees real people (water, loose clothing, crouching, fast limbs) and has not been compared with a lab or a coach’s stopwatch. Treat the numbers as an aid, and use the confidence label beside each value.
Where the camera goes
Seen from above. Angles are measured round from the front of the athlete; 90° is square-on from the side. Reference line: throwing direction.
Side view, 90° to the throwing direction. All javelin metrics. Front, rear and oblique views are not recommended.
How high, and how it should sit
Framing
Whole thrower and javelin for the entire throw.
The 50–75% band is our own guidance. No published source gives a camera distance in metres, so use it as a starting point and adjust until the whole movement fits.
Ready to record?
Tick each item as you set it up. This is a reminder, not a lock.
0 of 11 ready
All the camera settings
Every setting shows where it came from.
- Camera height
- No height is given. Keep it the same every session.
- Our guidance
- Distance
- No published distance exists. Stand back far enough that the full movement (arm circle, stride, follow-through) stays in frame with room to spare. Use the 1x lens and move your feet, not the zoom. The thrower, block leg, throwing arm and javelin must all stay in frame for the whole throw.
- Our guidance
- Frame rate
- 60+ fps. 60 fps minimum, higher allowed. Slow motion saved at normal speed works if you enter the recorded frame rate.
- From published guidance
- Resolution
- 1080p
- From published guidance
- Orientation
- Landscape or portrait both work.
- From published guidance
- Lens and zoom
- No zooming during the throw.
- From published guidance
- Lighting
- Clean lighting with enough contrast for the body and the javelin to stand out.
- From published guidance
- Stability
- Tripod; no handheld shake.
- From published guidance
- Calibration
- Existing tools use a manual release-angle guide that you align to the javelin before scores are trusted.
- From published guidance
Before you start
- Select the throwing arm in the app; the opposite leg is treated as the block leg.
- Start recording before the final crossover.
Cues for the athlete
Plain coaching cues, one thing at a time.
General
- Keep the elbow high and throw through the point.
- Brace the front leg, drive the heel into the ground and keep the chest back.
- Turn the rear hip before the chest opens; leave the javelin back.
Why camera position matters
Research behind these rules.
2D angles are only trustworthy when the limb moves in the plane the camera sees. Camera-side joints are measured more accurately than far-side joints, and timing is only as fine as one frame.