You'll have to be more specific about the job. In the field of medicine, there are numerous jobs including specialties. Generally, many jobs in medicine require some dexterity in the hands. But mostly it is the ability to diagnose and to understand how medicine interacts with the human body.
The situation in Haiti, for example, was baffling until a doctor diagnosed a patient with cholera. This was more cerebral than physiological.
Because medicine is cerebral, there are many disabled people working in medicine. Using microscopes and other implements, they can use their minds to find cures and solutions to medical problems. Stephen Hawking, for example, is an excellent example of a disabled person who has made great contributions to science.