When I first got Brahmas I read on this site that they shouldn't have perches at all. I disregarded that info because I have poop boards in my coops but after the cockerel injured himself and hearing the resounding thuds when my big hens jump down I've now added ramps or made lower roosts to help them out. I also make sure the shavings on the floor are DEEP to give them a softer landing. Imagine dropping a 10 pound bag of flour off your kitchen counter. Now think about a bird at 8 or 10 pounds or MORE hitting the floor every day....lots of stress to their legs/joints.