So your father is experiencing some hip dysfunction. Many people call "hips" different things and point to different areas when they describe them. When you say hips I am assuming you mean the ball and socket joint of the upper thigh. From your description of the symptoms it sounds like his hips are dislocating out of the socket.
If this is so then a proper examination would be warranted. It is suggested to have an orthopedic examination and possibly x-rays of the hips by an orthopedist or a chiropractor for further evaluation.
Depending on the cause/problem treatments will vary.