Two things: perhaps it's worth looking at the etymology and older meanings of "bend", given Hopkins's preference for all things Anglo-Saxon :) http://www.etymonline.com/index.php?term=bend

Secondly, I found this: "There is yet another acceptation of the word motion which defines the point where poetic desire invests itself into the world, and that is movement as bending, what Hopkins called "entasis". This curving, which seems to indicate a pregnancy of meaning (and which, as such, is indeed a "meaning motion") is what he identified as being the punctum that, in the shape of the blue-bell, for instance, catches his interest-"I know the beauty of our Lord by it [the bluebell]. . . . Then there is the straightness of the trumpets in the bells softened by the slight entasis and the square splay of the mouth" (The Journal 199). And the sketches of architectural details published in The Journal and Papers, which seemed to differ from the other drawings by their motionlessness, can be read as examples of movement in that sense of the term. An oxymoron of motionless motion, "entasis" is then the resolute figure of Hopkins's so particular vision of the world, a kind of veiled vision, in the sense that it is warped, as if there was always some faint bouger or blur in his perception of the Ruskinian veil of the earth." http://www.gerardmanleyhopkins.org/lectures_2000/heraclitus....

Who knows, maybe it helps :)