Legal use of hand & arm in blocking?

[Robert Goodman]

Then it would appear the blocker, unless he can achieve a quick knnockdown, has to choose between keeping the opponent from moving south and keeping the opponent from moving west.

Many would advocate in such a situation that I get the blocker's head in front of the opponent, and use the far shoulder to make contact. I'd like to keep my player's head from being in front of a moving opponent wherever possible, and I'm afraid that getting his head sufficiently past danger would leave only the far, trailing arm to restrain the opponent from westward movement, and that arm would have to hook around the opponent's near side to do so. So I think the type of angle block I want to do while being safe and effective would be more likely of the type I described previously, and maybe forego the arm in front of the opponent, turning it into a pure shoulder block, possibly supplemented by a chicken wing/flipper; but that makes for a narrower target.

Here's the video. Actually as I see it now, most of the time the blockers do manage to keep their forearm "inside" rather than wrapping around even the unrealistically thin dummy, although some of the time they do miss and wind up hooking the dummy.

[mbyron]

Neither holding nor illegal use of the hands are defined with respect to blocking dummies.

[FTVMartin]

Best thing to do would be reach out to a local association and see if they wiould come to a practice or scrimmage. We do that here and it gives a chance to explain what we are seeing and not just throw flags and move on with the game.
We use this time to answer any coaches questions as well. Last year I was working the line at a scrimmage and the interior lineman lined up looking like a "V". I was able to blow the play dead before the snap and have the coach come look at what I was seeing so he could fix the line.