Italian gamba and Catalan cama

Only now did it occur to me that Italian gamba and Catalan cama, both meaning leg, are probably related. Catalan cama is a false friend with Portuguese/Spanish cama, bed. This Italian dictionary states that gamba comes through Late Latin camba or gamba from Greek καμπή (kampi), meaning curvature, joint. This Catalan dictionary says that cama is derived from vulgar Latin and is first attested in the 14th century, and that word is of unknown etymology, probably from a pre-Roman time. What surprises me is that Italian, which has kept Latin voiceless consonants, has gamba instead of camba or cama, whereas Catalan--along with Portuguese and Spanish--which has usually turned voiceless consonants into voiced ones, has cama instead of gama or gamba.

Both cama and gamba are related to French jambe, leg, and jambon, ham.