Humans can become more flexible based on the visual field.

Most of this stuff how freely you are to move your muscles is center brain region controlled which gets info from our visual field.

If you do a wide stretch. And then you turn your gaze there, and try to go further out. Your brain will allow you more muscle movement.. next time you do the stretch you will be more flexible. In fact 25-40% more in some cases.

In fact visual system is hella interesting it's nuts how much it directs from time perception to how focussed and awake we are because we also have cells in our eyes that are angled Slightly upwards that just scan for light intensity. They literally dictate if we are awake and alert or not... It's why skylights work and why desk ergonomics tell you to offset your screen. Because you get sleepy if you look down on the screen more or less because you drown out those cells.

Heck did you know our peripheral vision literally runs on a higher frame rate of sorts. You can literally focus on more things and spot more stuff if you train yourself to focus on your peripheral vision.. the center focus in your eyes runs slower and is processing stuff with more detail..you can train yourself to be good at wheres waldo... In fact it's why it even works. Because if you spot something that looks like waldo there's small attention dips due to dopamine release where you will literally miss waldo if he's next to the thing almost looking like him.. because our focus literally tunnel visions Like that if we don't pay attention to the periphery.

If you really want to get your hands on some industrial or commercial grade explosives, robbing a construction company is the way to go.