Is my employer required to make accomodations should i fail my Fitness for Duty exam?

I am an Occupational therapy assistant who has been off 11 weeks from skilled nursing facility. When I brought in 25# weight lift restriction I was asked to consider FMLA and toold I could not work with the restriction.
I am going this week for Fitness for duty exam am I am concerned about passing this test. Do I as a nursing home therapist need to lift 50-75 pounds?
I also think they have added many different requirements to their "policy". Repatitive movements, squatting, etc. are not standard requirements.
I have never been issued a policy book with requirementsn before this. I honestly dont remember receiving one at all.
I also was never drug tested, physical tested or back ground checked prior to this incident. My manager stated that this came into effect for our department after my hire and we were "grandfathered in."
Please advise me if I need to be cautious of any legalities that I might be getting myself into by taking this exam,. I also understand ADA requires employerts to consider accomodations suggestions. A recent letter stated that hiring someone to be near my patients while they stood for their/m,y safety was considered unavailable. It also stated that we both agreed to this.
At this same meeting when accomodations were brought up (by myself)I had my 24 year oold son attend with me. I was told that ghaving a co worker near by or co-treating was not an option. I have since looked further and there are different "machines" that will guarantee a persons safety when standing.
If a "machines expensive. Who determines it is too expensive to be considered an accomodation?
Other accopmodations to consider ar for the rehab manager to issue me a patient load that is low risk.
What should my next steps be to protect my jiob, myself, and if necessary seek new employment?
Thank you in advance,