Car Wreck Accident and work release advice

A little over 3 months ago I was in a car accident. It wasn't my fault and I am confident once it goes to arbitration I will win, but I have some questions about my current work situation. I missed the two weeks following the wreck because of injuries. And i hve been seeing a chiropractor weekly and it was getting better. Last week I had to miss one day of work because of the pain and so I saw my doctor again and was put on "1/2 work days" being 5-6hrs because the pain sets in after being on my feet and I need this to heal all the way. Once I told this to my employer they said they were talking to HR to put me on a leave of absence. I have woked here almost six years so I would get some pay, but it becomes progressive less every few days and I can't afford that so I just decided to work full days for now because I really don't know what the heck to do now. Is it legal for them to force a leave of absence even though I am authorized to work 5hrs?