From Latin CAMBA, Greek cambè, which means curve, articulation. 

Le gambe (plural) can be LUNGHE // CORTE // SOTTILI // DRITTE // STORTE FORTI // DEBOLI // ROBUSTE 

ESSERE IN GAMBA, literally ‘to be in your legs’, to be in good health, strong, a very capable person!

‘Conosci Francesca? E’ davvero una ragazza in gamba: non solo va all’ Università, ha anche due lavori!’ —

‘Francesca is really smart: not only she goes to College, she also has two jobs!’

PRENDERE SOTTO GAMBA, to let things under their legs’, don’t take something seriously enough.

‘Giovanni fa sempre così: ha preso l’esame sotto gamba, non ha studiato abbastanza e non è passato!’ — 

‘Giovanni is always the same: he let the exam under his legs(underestimated the exam), he didn’t study enough and he didn’t pass!’

ANDARE A GAMBE LEVATE, to run with fast legs

‘Ho visto Gigi l’altro giorno: stava scappando a gambe levate da sua moglie’ —

‘I saw Gig the other day: he was running like crazy from his wife’

CADERE A GAMBE ALL’ARIA, to fall with legs in the air

‘Che figuraccia!! Sono caduta dalla bicicletta a gambe all’aria!’ —

‘What a bad impression!! I fell from the bike, legs up!!’

CHI NON HA CERVELLO ABBIA GAMBE, who doesn’t have brain, better have legs! Before starting any activity, better to thing about it throughly before you have to run around using your legs trying to find solutions to repair the situation