What a weird phrase to repeat over and over again when there's a goal being reviewed. As much as it's repeated I don't think there is a nice neat definition for this "kicking motion". A friend of mine (a Flyers fan) said of the Flyers goal overturned in the first overtime of the last Penguins game that his foot didn't leave the ice, so he didn't kick it. That seems like a terrible way to define it. Most of the borderline kicks are when a player is stopping and it hits his skate. Feet are bouncing. Snow is flying. Defenders are pushing. It's a confusing time to concentrate on keeping your feet still.
It's probably been suggested before, but I'd like to explicitly state my position. How about we disallow all goals off of your own team's feet? Hit it off a defender any way you want, but don't use your teammate's feet.
The first objection I can think of is "what is part of 'feet'?" Well, blades of skates are obviously part of feet. Laces and below are really pretty obvious. Do ankles count? My gut says no goals off of ankles either. Shins? Getting into a gray area again. Maybe the "no feet goals" rule idea needs to be changed. What about nothing below the knee? Nothing below the waist? I'm not sure where it should be. I think arms and hands should definitely be disallowed (in case they aren't already). Body deflections might be ok. If someone can deflect a puck off their head into the net, they deserve a goal. In any case, I think the rule should be changed from disallowing the motion (whatever that motion looks like) to disallowing the point of contact. It would make for less arguing and less confusion.