[MizunoJoe]

hcw,

Yes, the action of the right arm, is what keeps the left arm stretched and extended, or "straight." In SWINGING, the left arm is like a rope. In HITTING, the left arm is more like an ax handle, but ideally there should still be Extensor Action present.

This is correct in the context of Homer's recommendations, but limits the player to a large pulley stroke. Small pulley players such as Howell, Couples, and Mickelson do not use extensor action, but have relaxed trail sides to allow the narrow downswing.