Collision and sore shoulder

Yesterday morning on our walk, Flash did one of his charging runs at Dylan where Dylan normally tells him off because he hates it when Flash does that. Well, Dylan did the same yesterday, but somehow stumbled and Flash fell over him. Flash was limping for a few seconds and then was right as rain as was Dylan, so I didn't think about it any further. However, when I walked them this morning, Flash was limping on his front right when off lead and trotting, so I put him back on lead for the rest of the walk. He wasn't limping when walking, so again wasn't worried about it. Just thought I'd keep him on lead for a few days. Once back home, I got myself ready to take Dylan and Skye to the vets... and when we walked past Flash who was laying on the upstairs bed, he cried. I then checked his front leg and when I touched his shoulder he cried again. I got him to come downstairs slowly and with each step he cried. It was obviously very painful for him, he did put weight on that leg, but only just and very gingerly. I was then going to take him to the vet instead of the other two, but then decided that Mark would just put him on Rimadyl anyway for a few days as we know that he must have injured something in his shoulder! I still have Rimadyl left from Dylan when he hurt himself recently and I never needed to use those tablets then. So I gave half to Flash. Mark confirmed that it was the right thing to do. By the time I got back from the vet's, Flash was much happier and not limping too much anymore. Emily reported back at lunch time that he wasn't limping, though a bit grumpy and retreating upstairs. When I got home in the evening, I could see a slight weakness and shifting of weight in his front, but nothing drastic. Looks like the Rimadyl is working! I have also given him my mum's pills which contain arnica amongst other things. He won't be getting a walk tomorrow or Sunday and then I shall keep him on lead for at least a week - and we'll go from there.