Full Swing · Drill

Listen for the whistle in the post-impact zone

As a feedback cue, the speaker says to listen for a whistle sound in the post-impact section of the swing. When the pronation is driven by momentum from the body, the whistle occurs in the post-impact zone; when it is made with arm strength instead, the sound occurs at a different point, which the speaker frames as the difference between arm strength and body strength.