Attacksmurfen 说:
From a japanese movie? Is that meant as proof somehow? Are you serious?
Yes I'm serious. Yes it's meant as a proof (demonstration). Your view of movies being all totally unrealistic is as flawed as the view of those who think everything in movies is real.
And as for Japan:
The Japanese ultimately modified the heads of their spears into a number of different variations, leading to the use of the spear both on foot and from horseback, and for slashing as well as the primary use of attacking with thrusts
http://www.youtube.com/watch?v=ladijQstbU4
This isn't from a movie.
Of course that in tight formations like those used in Europe (hoplites, swiss..), you're not going to swing inside a formation, but that doesn't mean spears can't be used that way. Nicely seen in japanese warfare because japanese in general had more individualistic approach to warfare.
Spear handling
A yari (left) in mock combat
Spears, although apparently simple weapons, have a remarkable variety of wielding methods. Some are listed here from most passive to most active motions.
1. Holding the spear or bracing it against the ground, a charging enemy impales themselves.
2. The spear is thrust out with the arms alone.
3. The spear is held stiffly, and the thrust is delivered by stepping forward.
4. The spear is thrust out with the arms while stepping forward with one or both feet.
5. The front hand releases as the back hand and back foot move forward to perform a long thrust.
6. The spear is slid through the front hand, propelled by the back hand (a similar action to using a Billiards Cue).
7. The spear is thrown, often at a run, releasing when the opposite foot to the throwing arm is forward.
8. The spear is held couched under one arm, allowing a swinging motion as well as a powerful thrust.
9. The spear is swung rather than thrust, causing the tip of the blade to slice open the foe's flesh. The sheer momentum built up by swinging can be enough to cause serious injury even with the blunt end. The spear can then be brought around in a stabbing motion.
http://en.wikipedia.org/wiki/Spear
I think this pretty much closes the topic.