Hello, I recall that the practice of dismounting really picked up in the knightly classes around 1350. I was wondering what types of polearms were used by these knights. Early form of pollaxe? shortened lance (i doubt this one as in the 14th cent lances started taking on a specific form)? Any info would be greatly appreciated.

Try these threads:

Pole weapons of the 14th century

Staff weapons in the XIII and XIV century

14th century pole arms

The most common polearm would be the shortend lance which saw heavy use well into the 1420's among the men-at-arms fighting in the HYW. The most common lenght reported was lances cut down to 5 feet.

Axes increased in popularity during the period which saw the evolution of the pollaxe towards the end of the period, but shorter axes are mentioned in several battle accounts as well. And then there were of course a wide variety of swords with the types fit for two handed use and half-swording becoming increasingly popular as well.

Wondering on the construction of the shortened lance, Is it basically a spear, or is it different in any significant way? is there any pictures of a cut-down-lance/weapon?

A lance cut down to a shortened part that included the point was basically just a tapered spear.