I have flat feet. I was wearing converse for the past two months and lately I've been having lower back pain and knee pain. Is it okay to still deadlift and squat while while having lower back and knee pain if I'm wearing shoes with an arch support? It'll probably be another 2 weeks before I can get custom supports but I can wear my earth shoes or get inserts for my converses until than. I just hope my back and knees recover soon.