[Andy R]

Mr Kelley referred to the "checkrein" action of the left arm, where it applies a constant resistance to the effort the right arm makes to straighten.

Confusion arises from guys thinking that extensor action is the right arm pulling, and keeping, the left arm straight; whereas it is the left arm preventing the straightening of the right arm.

Mr Kelley did not deal in confusion: that only occurs in individual interpretations of what he was very specific about.

Thats a great post and clears up some of my confusion about Extensor Action. Now I see 1-L-15 simply as a continuation of proper Extensor Action. Great stuff.