Perfect form in javelin isn't about looking smooth. It's about hitting the targets coaches measure, phase by phase. Here's what perfect javelin form looks like at each phase, what coaches grade for, and how the AI compares your form to the standard frame by frame.
Each phase of javelin has a target. Takeoff angle. Body lean. Foot strike. Release height. "Perfect" means hitting the target on each phase, in order. The AI grades against the targets, not against how the rep looks.
A frame can look ugly and still work. A clean-looking frame can still cost you. The AI grades the mechanics, not the look. You stop chasing pretty form and start chasing the targets that matter.
Don't compare yourself to a pro's highlight reel. Compare your phase 2 to the standard for phase 2. The AI does this for you and tells you the gap, frame by frame.
Upload a clip, AI grades each phase against the form standard, and tells you the specific gap to close. Not a vague "work on your technique," a concrete read on which target you're under and by how much.
Follow up in chat and ask questions. The AI remembers your analysis and speaks the language of javelin coaching.
Each phase has a coaching cue, a measurable target, the frames a coach pauses on, and the failure mode AI flags most often. Use it as a self-diagnostic checklist on every video.
6-10 strides at moderate pace, building to controllable speed (5-6 m/s elite). Not a sprint; control is critical.
2-3 lateral crossovers preceding the throw. Right foot crosses behind left (RH thrower), turning the body sideways.
Last crossover lands long, lowering CoM. Loads the throwing leg.
Front (left) leg plants firmly to stop forward momentum, converting it to rotational and vertical lift via the trunk and arm.
Trunk arches and unloads (whip), arm comes through last (kinetic chain). Javelin released at 30-36 deg with velocity 28-30 m/s elite.
Right leg lands forward to absorb momentum. Stay behind the foul line.
The numbers coaches grade against. Levels run from beginner through elite, your AI form check compares your reps to the level above you.
Primary sources behind the numbers and methods on this page.
Five common questions about javelin that come up in coaching.
A directory of every javelin page on the site, from broad analysis tools to specific phase deep-dives. Each entry points to a focused write-up.
Download the app. Film a rep. See what the AI sees. Free first analysis, no card, no account required.
