skittsh or sad?

[delkampg]

we just got a dog from the shelter and when we were looking at him he was really skittish and shy, with his tail between his legs, he only stood in one place and almost made no eye contact. when i picked him up from the vet i had to pick him up to put him in truck and he stood up and didn't move from where i set him, until i hit the brakes a little hard and he fell...not hard though. i carried him inside and he didn't move i went into the kitchen and got him some food and when i came back he was hiding behind the chair. i had to lift him up and bring him over to his bowl. he wouldn't go into any rooms unless i carried him then he would walk into only the rooms i carried him into earlier. he wont go up or down any stairs, which might be because he was just neutered. when he was sitting on the coach i noticed he grinds his teeth. i took him out side and there were kids out across the street and he ran towards them and seemed to show just a little bit of happiness. then when he was in the back yard and there were kids playing in the background and his ears perked up. do you guys think this dog has been beaten or what?