if its just a finger you could use

a wire deformer

or non-linear deformer

or a lattice deormer

or a blendshape

or create a skeleton in the finger, smooth bind to the finger, shift select from the first joint you made (at the wrist) until you get to second to last.., press 'E' for rotate.., and that should work

this last choice also works well for things like birds wings.., very simple box model birds seen from a distance, it will not stand up to close inspection (close camera shot)