Help on My sons tattoo im getting! I want his footprints just dont know where to get them!?

I was thinking my back left shoulder, both his feet with name and birthdate, but i wouldnt be able to see it and theres gonna be a shirt covering it 90% of the time, so im trying to think where to get it thats a good spot, i was also thinking my inner forearm, and have his toes pointing towards the crease. Can somebody help me on the area? or give me any other ideas on a good tattoo to get for him?? Thank you so much.