The uz nidbiru (r binyomin zilbershtein zt”l) paskens that its better to sit next to a girl then behind her. cuz he brings a rayah that theres a din of “achoreiy isha” even by sitting.
but for all those willing to deal with arayos issues head on , heres a little secret, the gemorah says that 2 specific amurayim are considerd tznuim legabey yichad and the mechaber paskens like that so anyone today acording to mechaber is considered prutzim and in a workplace with closed door wont help a feelow yid, even acording to the remah whos meykil r moshe says someone who watches tv is considered a parutz and duznt help for yichud, go figure how many ppl working with females are forgetting this. this is without adressing the real tzniyus issues goin on in workplaces. The amurayim had to deal with arayos somehow we got better????????????