Phase by phase, not gut feel
Good javelin technique isn't a vibe. It's a sequence. Each phase has clear targets you can measure: angles, foot positions, body lean. The AI tells you which phase in your rep is costing you the most.
Javelin technique is about precision. Every javelin rep is a chain of phases. Each phase sets up the next. Get the phase-by-phase breakdown coaches use, plus AI that grades your own technique against it, frame by frame.
Good javelin technique isn't a vibe. It's a sequence. Each phase has clear targets you can measure: angles, foot positions, body lean. The AI tells you which phase in your rep is costing you the most.
Watch a javelin coach review tape. They pause on the same handful of frames every time. The takeoff, the plant, the release, the clearance. The AI pulls those exact frames for you.
Most form errors trace back one or two phases. Fixing the symptom doesn't help. The AI traces the chain back to the cause so you fix the right thing.
Upload a clip, AI tags every phase, marks where technique breaks, and writes a coaching note for each one. The same phase-by-phase read your coach would give, but on every rep, not just meet day.
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.