Each client is different, obviously, with regard to their own abilities. Because of his size, I would be concerned and considerate about having him get up and down from the floor. He may or may not be ready for those exercises. I always start conservatively, perhaps with some incline exercises, and progress the client when they are comfortable and confident with their form. In reality, as trainers we should program the exercises around our client abilities–instead of having our clients perform exercises that we want them to do.
That being said, you could try a body weight exercises at different inclines. For example, wall push-ups to start. They could be progressed to a windowsill ledge push-up, to a bench push-up, and eventually to a floor push-up. Some of the same incline techniques also work well with planks. Another great body weight workout option is the TRX system. I use this with many different clients–it works well for all levels. Overall, I would go slow and work with abilities–it will give him more confidence to do exercises he can do well.
Hope this helps you and good luck.
I had a similar situation when i worked for a physical therapist. The patient was very self conscoius so I had to respect this and be careful as to what I was asking this person to do. The therapist and I acutally were able to start exercises- that we eventually wanted to be done on the floor- on a reebok step. I am only a little over 100 pounds, so the idea for this patient to get down on the floor and not be able to get up with my help and possibly cause injury to himself and to me really made him fearful of the floor.
We started with the step and set it 4 high (i think)
When we saw progress (and also really had to boost the self confidence with positive reinforcement through words) we would remove one step height from the set up. Eventually we got to a point where the patient was only using the step itself and was comfortable enough to move to the floor. It took a while to get to that point and a lot of patience, but the patient was so proud when he was able to get down to the floor and up (with help) but it wasn’t as much of a dramatic “show” anymore, that the patient wanted to learn more floor exercises to try at home.
I dont know if this is something you could try, it was what worked for us but maybe it could give you ideas of ways to make something like this work for you too. Good luck with your client and awesome job on the progress you two have already made!