I am unsure of which year the movie came out but there is a group of kids being chased by a killer or a few killers. In the end the group of kids (or might be a family) get away by killing the villain with a huge log with long branches sticking out of it. They have suspended the log from wires and one kid or person is the bait and when they are running through the forest someone releases the log and it swings down and impales the villain. That is all that I can remember. Sorry if it isn't a whole lot of information.

Could be 1983's The Final Terror.