I'm an Alabama attorney. For the past year or so I've, primarily, handled workers' compensation cases for clients.
Keep in mind. I'm not your attorney, I'm not licensed to practice in your state, and I don't know anything about Arkansas workers' compensation law.
Here's how things would work if you were in Alabama.
From the date of your injury, there would be a three day waiting period until you started receiving temporary total disability checks each week for 2/3 of your average weekly wage over the past 52 weeks worked for your company. You would receive these checks until your authorized treating physician released you back to work.
In the alternative, you could return to work a different job that falls within your restrictions and, if the pay for that job was less, you would receive temporary partial disability checks that would make up the difference.
As for your "lump sum" settlement, there are three benefits for each workers' comp case. Indemnity, Vocational benefits, and future medical treatment.
Vocational benefits only come into play if the injury is not to a scheduled member.
In your case, your injury is to your shoulder, which is outside the schedule. When your doctor places you at maximum medical improvement, you will receive an impairment rating. For our purposes, let's use 5%.
To calculate the indemnity value of a 5% body as a whole impairment you multiply 300 weeks by .05 (your impairment rating), then by the comp rate (2/3), then by your average weekly wage.
So, (300)(Your Impairment)(2/3)(Your Average Weekly Wage).
It's slightly more complicated than that because you have to factor in accrued weeks at MMI, weeks of TTD paid, and present day value of lump sum payment...
If you don't hire an attorney, you are likely to receive an offer of exactly the statutory scheduled member impairment. Any workers' comp. attorney should be able to do better than that for you, along with making sure the calculations are done correctly.
In Alabama, attorney's fees are limited to 15% in workers' comp. cases. It is, literally, the cheapest you will EVER hire an attorney for ANYTHING.
I don't know how things work in Arkansas, but in Alabama, if someone told me they handled their workers' comp. claim on their own, I would call them a fool.