I know that Warhammer is not the DF universe, but I really do believe that the Warhammer people have the appearance of dwarves mostly right.
Here's a couple that I really like:
1) Armored dwarf.
and
2) Unarmored Dwarf
and
The only thing that I disagree with in all four of these images, from my own personal in-my-head picture of dwarves is that a dwarf standing upright should be able to touch their fingertips to the ground.
In order to actually be able to fight reasonably well with weapons, you must have a wide range of motion and full coverage of the body frontage with your arms and hands. With shoulders and torsos as big as what dwarves have, to give themselves good frontal coverage and enough reach to be decent in combat, they need very long arms compared to their bodies.
Having extremely long arms and very short legs also allows dwarves to move around without much difficulty even with a missing leg. Basically a "crutch" for them would just be a gauntlet to protect their knuckles.
At times I really wish I could draw, I'd love to put my in-my-head image of dwarves on paper
Additionally, with really long and powerful arms and very short legs, dwarves could actually move very, very quickly across the ground using their arms and legs together much the same way that a gorilla moves. If you have ever seen a gorilla move quickly across the ground, it's pretty impressive looking