Players on both the LPGA and PGA tours have been measured.
There is a noticeable difference in hip speed, a minimal difference in torso/rib cage speed and a very noticeable difference in arm (specifically left arm) speed.
Average hip speed is higher on the LPGA, rib cage is barely higher on the LPGA and left arm speed is significantly higher on the PGA tour.
A kinematic sequence chart shows left arm speed to be the body part most directly responsible for club head speed.
A left-handed cross court back hand and left handed frisbee throw are similar to a right handed golf swing and in those motions, the left arm fires off the chest. Only firing the body would get you nowhere.
Not even in things like jogging, field goal kicking and martial arts kicking are the arms taught to be passive.
So why in the (fill in your choice of expletives) is golf the only activity where we’re taught to have passive arms…and why are we firing the lower body for speed?
For much more on this, check out this post.