Meshes not deforming properly when imported from blender

Hey everyone,

I'm currently attempting to import a humanoid model from blender to unity. I created a little walk animation for him (well, a "run around with flailing arms" animation is more accurate).

Here is an image of him from blender: (I'm no artist, obviously, haha)

Upon import the animation seems to work correctly, but the meshes aren't deforming with the animation. Here is a screenshot of the final state of the dude in his animation:

Does anyone know what might cause this? It's as if it's taking the initial geometry of each of the meshes and just moving those with the bones, rather than actually deforming them as the bones move.

Thanks for any assistance!

Is your mesh skinned properly? Can you import fbx file successfully back into Blender?