There are 3 (main) reasons why subluxations occur:

Emotional stress - Every person responds to stress with a fight-or-flight response, this is our sympathetic system.

If a bear comes at you, you either get strong enough to fight the bear or strong enough to run like crazy.

When the bear is no longer there, any damage that may have happened during the fending off of the bear will get healed with the parasympathetic system.

But when you encounter emotionally fraught situations, for example dealing with a nasty divorce, a family crisis, or the emotional roller coaster we've all been in world wide due to the pandemic, it is like the bear has his arm around your shoulders 24/7.

This constant fending off of the emotional-weight causes sleep and digestive issues (in the grand scam of things, how could you possibly sleep or eat if you're fighting off a bear...?)

This repetitive emotional stress, causes muscles to contract, which then leads to muscle spasms, guarding, and compensations in your posture, which lead to spinal subluxations.

Physical stress - It's not just the slips, falls, bumps or incorrect lifting, but the repetitive daily actions.

Bad posture is a big one.

Repetitive movements or sustained poor posture are like a pebble in your shoe: at first, it's not a big deal, but over time it can become excruciating.

Chemical stress - These are toxins consumed by mouth, inhaled, or rubbed onto the skin that the body doesn't know what to do with, such as cigarettes, alcohol, medication, pollution, and certain types of beauty products.

Whatever the body can't tolerate will cause chemical stress in your system and the nervous system will become overwhelmed.

If the nerves that control certain muscles are inundated, then muscles can become unbalanced, causing spasms and ultimately, subluxations.