I am not sure whether I would call myself ‘specialize in’ but I have have been working with a fair number of clients of this description, be it neurological or autoimmune, over the years. It is an area of special interest for me, and I tend to dissuade ‘apparently’ healthy clients at this time from training with me so that I have room for those who are not.
I do not have any formal certifications for those conditions, and I also do not know of any that exist in the personal training field of certifications. Even the ACE AHFS does not have a chapter on neurological disorder at all and little about autoimmune.
I did not all of a sudden decide that this was going to be my niche but I started with having a few clients with those conditions and was also exposed to a good number through a club where I teach a few classes. This combined scenario has afforded me the opportunity to observe and draw my own conclusions.
The one common factor in this field is that there are no commonalities except one: people who have condition X or syndrome Y are more than just that. Many of those problems spin off challenges that are ultimately unrelated to them. For example, if you have a client who has frequently fallen because of MS, she will have muscular imbalances because of those falls, making her possibly even more unstable and causing more falls. This can become a vicious circle which is often blamed on the condition. But we as trainers can very well address the additional problems and thus help quite a bit.
How the training is conducted depends entirely on the result of the assessment and the input from doctors and PTs. As Brian points out, there are good and bad days, and you need to be very flexible and ready to modify your plan or make a new one on the fly as necessary.
People with those medical problems are often very fearful. They no longer trust their bodies, and the dialogue between client and trainer has to be always an antenna out towards comments so that they can be re-framed.
The way I have ‘established’ myself is by simply having clients who improved their quality of life through my training, and they have been telling others.