Is it OK for male Dr. to ask female patient to undress in front of him?

Is it OK for male Dr. to ask female patient to undress in front of him? A friend of mine went in for a check-up. She had complaints about calf pain, and the doc asked her to take off her pants so he could examine her legs. (she was wearing a gown, with a camisole and jeans under) He stayed in the room, not looking at her undress - he was writing in the chart - but there was no privacy screen or anything. There was no one else in the room when he examined her legs. He also had her lie down, and he checked the area around her hip joint. (she has stiffness and pain in her hip too.) After, he asked her to put her pants back on, and again he stayed in the room. Are there any rules about the doctor asking the patient to undress and dress without providing privacy? Also I was wondering if a male dr. can examine a female without another female in the room. I volunteered at a hospital, one of the things I was asked to do was to stand nearby while a male dr. examined a female patient, so I thought that was standard procedure. Honestly, my friend didn't mind, she feels comfortable with this doc. I was just wondering.