mutex77

Im working through a "100 blues licks" book, and one of the riffs it has a doublestop C power chord (5th fret on D & G strings)

The book suggests playing it barred with your 3rd finger, and the tab shows to play it with vibrato.

I can get vibrato on a doublestop if I use 2 seperate fingers, but with 1 finger barred its not happening.

Are the movements just like regular wrist vibrato and I just need to practice it more? Or is there some other technique?

This is basically the riff from the book, with the number on top specifying finger:

Livingtime

Use your 3rd finger for just that seems a bit silly in my opinion Pinky and Ring fingers would be the wiser option. What ever is most comfortable though

With 2 fingers its easier to do vibrato.
With 1 finger its definitely harder, possible, not as good as 2 fingers and harder.

Either way, vibrato will come from your wrist.