Having the ‘fingers all thumbs' ; being as awkward in delicate manipulations as if using the thumb only.
The Century Dictionary (Public Domain)
Use "thumb-fingered" in a sentence
"After Greg, or Dr. Blockhead as I've come to think of him, the thumb-fingered surgeon who wants to be a shrink, blows his psychiatry interview despite Joan's shrewd advice, he's breaks out his bottle of whine."
"Yesterday there were more candidates confirmed but the likes of Guiliani and McCain are melting like the Wicked Witch in the Wizard of Oz. Things are changing rapidly on the IFTR website; Failor's thumb-fingered approach is not making him any friends outside the beltway."
"While the moment is also fraught with danger, we need to understand just why those in power would choose such a thumb-fingered approach to the problem of cover for the election they are poised to steal."