both Shawn and Joanne are right in pointing out that you need to work as part of a team with the doctor and/or PT. However, having a bulging disc by itself does not have to throw you into confusion.
If the situation is a recent problem, working with the PT is mandatory. But you will find a lot of people with bulging discs who are asymptomatic and go through the day without pain. In that case, you may even get a physician’s approval without any restrictions on exercise. Ask whether they ever saw a PT and ask for a list of the exercises that they got.
In any case, I do my own assessment as with everbody else. If I have PT exercises, I start with those and watch how the client is doing. Else, I start very conservatively (lying down, pelvic tilts, teaching neutral spine), observing the client like a hawk to see whether my posture cues can be translated into correct movement. I saw that you train at a gym, and that may tempt you to put a client on machines. Be aware that correct posture there just as important; people often get a false sense of security with machines.
However, there may be more to the client than what I am describing. If you feel that your skills at this point in your life as a trainer are not up to the task, you will do yourself no harm in saying so.
As coincidence would have it, I just posted a blog that deals with a somewhat similar situation, I think. Please read it if you have time.
In regards to your question… I’ve read all of the responses you’ve gotten so far, and I don’t see anything that could be added without knowing more specifics about the situation. I think Karin offered some excellent advice, all around. I especially agree with what she says about machines.
The only thing that I would like to bring to the table here is… If you know someone with bulging disks, perhaps you should consider telling this person about inversion therapy? I like to consult the LIVESTRONG foundation on a variety of different topics. Here is what they have to say about it.
I strongly urge you to check out this article. Also check out the resource links at the bottom of the article to get further information on the topic. Like Joanne has said before, you can’t give away what you don’t own. Own the knowledge about this condition, and you’ll probably find yourself giving quality services to those who suffer from it. (if they’re cleared by a physician to exercise)