All fingers and thumbs
Clumsy, unable to hold things steadily in one's hands. 'All fingers and thumbs' is how we might describe ourselves during a temporary loss of manual dexterity.
This joins head over heels in the list of little sayings that don't make a great deal of sense, as having fingers and thumbs is hardly unusual. Both phrases have changed in form over time yet retained their original meaning. Previously 'all fingers and thumbs' was simply 'all thumbs'.
In 1546, John Heywood published A dialogue conteinyng the nomber in effect of all the prouerbes in the Englishe tongue - no mean undertaking, even in the 16th century. In this, he gives:
"Giijb, Whan he should get ought, eche fynger is a thumbe."
In 1870, The Echo printed a direct reference to all thumbs:
"Your uneducated man is all thumbs, as the phrase runs; and what education does for him is to supply him with clever fingers."
It isn't clear when the transition to 'all fingers and thumbs' was made, as the phrase doesn't occur in print until the late 19th century.
The Lotus Corniculatus flower, called 'fingers and thumbs', is unrelated to this phrase and is so called because of its appearance.
Similarly, the (now obscure) slang term 'finger and thumb' is simply a rhyming slang term for 'chum'.