An arms-only swing is exactly what it sounds like: the arms swing the bat while the body barely turns. It's quick to spot on video — the chest is still mostly closed to the pitcher at contact, the arms reaching out to the ball instead of the body delivering the barrel to it. It can even feel fast, right up until the arms run out of speed, which they do quickly. The body is the engine; the arms are just the linkage.
Turn the barrel to the ball, don't reach for it
A full swing rotates your whole torso through contact — by the time you meet the ball, your chest is turning to face the pitcher and your back shoulder has come all the way around to the ball. The barrel gets delivered by that turn. An arms-only swing skips the turn and sends the hands out to the ball instead, so the barrel arrives on arm strength alone. There's a ceiling on that, and it's low.
The fix isn't more arm — it's finishing the turn. Let the back shoulder come all the way to the ball and let the chest face the pitcher at contact.
What the camera reads
This read lives on the behind view — camera down the pitch line. From there CoachVision measures your turn completion: how fully your shoulders finish their turn to face the pitcher by contact, against an anatomical full turn. Near a full turn means the body swung the bat; well short means the arms did.
Two honesty points you should hold onto. First, this is turn completeness, not sequence — it can tell you the body turned, but it can't tell you whether the hips led the shoulders (that's separation, and it lives on the open-side camera, not this one). So read it as "did the body turn all the way," never "was the order right." Second, the behind view can't see your load, your hand path, or your extension — those run along the camera axis and vanish. A behind clip that says nothing about them isn't finding a flaw; it's the angle.
The fix — train the engine
Med-Ball Rotational Throws: from your batting stance, load the back hip, fire the hips first, and let the arms come along late to throw the ball into a wall. The throw is impossible with arms alone — you have to turn your whole body — so it teaches the exact move an arms-only swing is missing. Three sets of six each side, a ball you can throw with intent, not strain.
No-Stride Swings isolate the turn: start at your landing position and swing with rotation only, feeling the chest come all the way around to the pitcher. Ten off the tee.
The cue: turn all the way through until your chest faces the pitcher at contact. Film one behind-view swing, check your turn completion, then a dozen med-ball throws a round until the body — not the arms — swings the bat. And film open side next time to unlock the load and hand-path reads this angle can't see.