I have been working with a gentleman with Parkinson’s for 12 year. I had actually worked with him already when he was diagnosed, and we have stayed together all those years. He is now severly disabled by Parkinson’s, and I train him at home with the assistance of another person for his safety.
You do not indicate the progression of the disease and how it manifests itself with the client you have in mind.
Looking back at how I worked with my client (always with the approval of other health care providers), my main goal was to develop as much strength, flexibility and balance as possible. When walking is getting difficult, it can often still be performed on a treadmill that assists in movement. Stretching is very important because Parkinson’s sufferers sit more and more because moving becomes difficult. And because of that, posture becomes compromised with rounded shoulders and a head forward position.
Kepp in mind that clients with Parkinson’s often have no control over the way their bodies move, and asking them to perform precise exercises can become quite frustrating.
I teach Pilates myself but I probably would not use it beyond some very basic instruction on core engagement. Even if the client can still get onto the floor, I would do as much standing as possible and only resort to sitting as necessary.
Another point to consider: I only train my client for 30 minutes and have done so for a long time because the typical hour of personal training can be too demanding. As the diesase progresses, prepare yourself for frequent cancellation on short notice. Medication needs to be adjusted from time to time, and you may need to change the exercise approach then. A person with Parkinson’s can feel okay in the morning and all of a sudden feel so weak or out of control that he cannot kep the appointment.
You will eventually watch your client having falls, and you can only hope that it is not under your supervision. Every fall has negative consequences. A final thing to remember: no matter what you do, you will watch things get worse over time, and it is a heart-breaking experience.