He starts opening car door before car is stopped. He pushes in a crowd to get through. He carry’s his head very forward and leans forward when walking. He walks as if he is trying to get his feet to keep up with the forward momentum of head. This gait is more prominent in the house without a cane than outside with a cane. He has never been like this before.
As for the walking leaning forward... I had noticed with my Mom, who use to walk very straight, once she started to use the cane she was bending over. Thus, without using the cane, she still had that bent over appearance as she walked. Her spine was twisting.
My own Dad never developed that bent over position as he went to using a rolling walker quite quickly, preferring that over the cane. I believe with the walker, people tend to stand up straighter than using a cane, so their spine will stay straight.