Steel toes make the front of the shoe heavier than normal. It's an odd balance and can put stress on the ankle and heel, especially if the heel of the shoe does not fit well. What is the sole of the boot make of? If it is too hard then a cushioned (e.g., gel) arch might be best. But, if your arch or heel are hurting because of lack of support then that is a different problem. If it's the arch then a firmer arch support would be best. I prefer sports arches, e.g., Spenco, and I find the 3/4 length better than the shorter, arch only, length as they provide much better foot stabilization. Sometimes an arch support can help if your heel is slipping inside the shoe but your local drug store or shoe store should carry heel pads that stick inside the upper end of the heel to stabilize it inside the shoe. Good luck!