[Jeff]

12PB

I think that "blast off" is Homer Kelley's wording. I simply think of the left arm moving away from the chest wall when the upper torso rotation slows in the mid-downswing. The rate of angular acceleration of the free-wheeling left arm remains the same, but its angular speed increases as it freewheels towards impact - because there is no impedance to the release of PA#4 and the freewheeling forward movement of the left arm.

This graph shows that the slope of the left arm graph doesn't increase when the shoulder rotation slows. However, angular speed increases.



Jeff.