One of the amazing things about the body is that it will always try to use energy in the most efficient way possible. Once we stop using a muscle, for example, the body will no longer put energy toward it. The muscle will slowly lose its function because of lack of use and energy. This also means that same muscle loses strength to hold whatever part of your skeleton it is supporting, which can lead to pain.
“I just can’t move like I used to.” Maybe it’s time to consider that we can’t move like we used to because we don’t move like we used to.
To get a glimpse of the box you are in, find a notebook and a pen. Every day write down how you move. An example is: I get out of bed, grab a cup of coffee, get in my car, sit in my desk, get back in my car, sit on the couch, go to bed. Once you see the pattern of what you aren’t using, you may start to see why you “can’t” use it.