a clan of Mountain giants believe a human mage can lead them to victory against the slightly superior Mist Giants of a neigboring mountain…their ancient cave drawings (think Bayern Tapestry on cave wall) tell them so…
In ancient China, women bind their feet for cosmetic reasons, resulting in them not able to walk without help and walking in a shuffling gait.
Possibly this can be modified such that people do it for less stupid reasons.
Disclaimer: This is NOT a racist remark since I'm Chinese myself and hence entitled to freely judge Chinese customs. NOT sexist either since I'm female as well.