Ultrasound might be helpful once the inflammation is past. Other than that my guess is activities that will get blood flowing to the injured area without further stressing it would be the most helpful. For most arm injuries running will do that. One thing you also want to do is keep the arm stretched if you can do so without further injury to avoid forming scar tissue. In addition, you’ll want to strengthen the other muscles that help out the injured muscle if that is possible.
As long as you are still feeling pain there’s still some inflammation so either ice and/or a NSAID is indicated.
The problem is that other than doing the running you’ll probably want a PT helping you with the other things because it is tricky knowing just how much you can safely do and of course the ultrasound isn’t something that is self administered.
I’m not a doctor so take anything I say with a grain of salt and I’ll echo the others who said to go see a doctor if there’s pain and not just soreness.