Animation streches the model all wrong

I have a bunch of animations, though in my 3D program and preview in unity, there does not seems to be a problem. As I set it up for the model I am going to use, the fingers on the model streches back to the original model preview stands location. This problem only happens with this one animation out of 10 others.

I checked out other forums threads I could find, and tried out changing the quality settings, and scaling of the model parts, though nothing seems to be the solution, yet.