Forward lunges

Hello

I was wondering about alternative moves to forward lunges? You see I have bad knees and was told.by my physio to not do forward lunges but only reverse lunges. So I always do reverse lunge when a forward lung is called for, I’ve done this for years, but have started wondering if maybe there’s an alternative as forward lunges works s different part of the leg, and sometimes I might end up doing a lot of reverse lunges in one workout and I don’t want to put myself out of balance.

Thanks in advance for any advice given, maybe what I’m doing is fine, but thought I’d put it out there to hear others thoughts and ideas