YAHOO LOS ANGELES-Jennifer Aniston and T.J. Miller had an ‘’immediate chemistry’’ on the set of ‘Christmas Office Party’ after she ‘’broke’’ his rib cage.

The 47-year-old actress and the 35-year-old star had an ‘’immediate chemistry’’ on the set of the forthcoming film when she got heavy handed with the actor, causing his body some damage as a result. He said: ‘’The second I met Jen, if I can call you Jen, she immediately put me in a headlock. ‘’And then did a very strange pile-driver move, and my rib cage was broken. So it was sort of an immediate chemistry, I thought.’’ The pair play brother and sister, Carol Vanstone (Aniston) and Clay (Miller), in the movie which sees the ‘Friends’ star’s CEO alter-ego attempt to close down the Christmas party at the Chicago branch of her company, which is run by her sibling.

But it results in the staff staging a wild bash to try to impress a potential client.

‘’There was a couple, they’re extras, and she was up on a filing cabinet and his head was between her legs and that’s what they decided to improv because they were told to do whatever they want.’’

But Miller insisted the extras were the ‘’most important part’’ of the motion picture because they had to film countless dancing scenes without music.

Speaking at Entertainment Weekly’s PopFest in Los Angeles, he added: ‘’I want to be very clear that the background artists were the most important part of this film.

‘’They were dancing in the background, with no music, for 12 hours, a day, for weeks and weeks. Just silence.’’