Yesterday I fell from my bike and landed on my shoulder, which initially did not hurt, but today I have got a quite bad muscle ache where I landed.
I know this is not unusual, as was confirmed by some googling and wikipedia, but I was wondering why overuse and falling, seemingly very different, can have the same result.
Who says it’s the same pain? You might just not be able to tell the difference.
However, there are similarities. For a long time, we thought that “overuse pain” was due to a buildup of lactic acid. Turns out, it’s actually due to microtearing. If you work a muscle too much, the strain will team the muscle fibers and that causes soreness. When you fall down, you can also tear muscle, either by direct impact, brief dislocation, or a reflexive tensing. So the pain would be rather similar.
You mention shoulder pain, though. Joint pain can be difficult to diagnose because there’s a lot going on there. There aren’t just muscles- there are tendons, ligaments, cartilage, and other point parts that could be injured, too. So without being in your body, it’s hard to say what’s wrong with you.
I have a abundance of personal experience in this area, having fallen many times including from a bike. I call it the 48 hour rule. Many injuries from athletics and trauma of falling are at their worst at the 48 hr. point. Initially, there is very little inflammation and therefore little plain. The inflammation builds for the first 48 hours and so does the pain. I have found that light activity as soon as possible tends to reverse the process more than resting.