Block setup determines drive angle
Front block 2 foot-lengths from the line, back block 3, comfortable spacing for your build. Any farther and you can't drive; any closer and you can't set. AI flags block setup against the standard.
The sprint block start is decided in the first 0.4 seconds. There are four pieces: block setup, set position, drive angle, and the first 5 strides. Each one sets up the next. Here's the breakdown, plus AI form check on your own block starts.
Front block 2 foot-lengths from the line, back block 3, comfortable spacing for your build. Any farther and you can't drive; any closer and you can't set. AI flags block setup against the standard.
Hips slightly higher than shoulders, weight forward over the line, head neutral. Most block-start errors trace back to a wrong set, hips too low, weight back, head up. Easy to spot on video.
Drive angle is held when stride length increases gradually, foot strikes are behind the center of mass, and the head stays down through stride 5. AI grades each stride independently.
A side-on phone clip from 20 feet captures the full block-start sequence. Upload it, AI grades the setup, set, drive, and first five strides separately. Each gets its own coaching note.
Follow up in chat and ask questions. The AI remembers your analysis and speaks the language of sprints coaching.
Common questions athletes and coaches ask about this topic.
A directory of every sprints 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.