I used afetr my hand accident (and still use as a bass warm up) a variation of "The Spider" Start by playing on fret 1, bottom E with First finger, fret 2 same string with second finger, fret 3 with ring and fret 4 with pinky. Move to the A string and start on fret 2 with first finger and repeat the sequence, D string starting 3rd fret and keep going a string at a time and up the neck finishing back on Low E at with your pinky on 14. Then reverse the process back down to the start. Do it as slow as you like and work to build uo speed as your fingers improve. It's not incredibly musical but the object is to get the fingers working and strengthened.

Good luck

Steve