Legal Question in Employment Law in California

Re: mandatory work

Yes. If you are being compensated by your employer, you are required to perform any reasonable order (unless unlawful or dangerous) given by the employer.

Moreover, employers are required to provide reasonable accommodations for employees with disabilities. Accommodations can be physical (wheel chair ramps or lifts) or assistance (assigning an employee to push the wheel chair).

It appears that your employer is doing what it is required and you have been selected to perform the assistance duty.

Re: mandatory work

No. Not unless there are some really extreme 'accommodations' required by the employer, and they are obligated to provide an 'assistant'. That would have to be done seperate from normal duties. Talk to your HR dept with your issue and seek correction.