all thumbs
Uncoordinated or clumsy with one's hands. My mother does beautiful calligraphy, but I'm all thumbs—I can barely hold the pen!
all thumbs
Fig. very awkward and clumsy, especially with one's hands. Poor Bob can't play the piano at all. He's all thumbs. Mary is all thumbs when it comes to gardening.
all thumbs
Physically awkward, especially with respect to the hands, as in When it comes to knitting, Mary is all thumbs. The notion of this idiom derives from a proverb in John Heywood's collection of 1546: "When he should get aught, each finger is a thumb." 
all thumbs
 BRITISH, AMERICAN or all fingers and thumbs
 BRITISHIf you are all thumbs or all fingers and thumbs, you do something in a very clumsy way. Can you open this? I'm all thumbs. When I came to give the baby a bath, I was all fingers and thumbs.
 all thumbs
 Lacking physical coordination, skill, or grace; clumsy.