Sometimes emotional trauma or stressors can result in physical symptoms because the memory of the trauma is stored in the fascia. Fascia is a connective tissue, primarily collagen that forms a matrix throughout your body and helps to support overall structure, stabilize and to aid in movement. Think about when you burn yourself - by the time you realize that something is too hot - you are already burned. It takes some time for the pain signal to reach the brain and then for your brain to send out a response for you to remove the hot item. In the meantime you have cells [many of them which are in the fascia] in your body that are storing memories faster than your brain.
When you are responding to trauma, sometimes it is so overwhelming that before your brain has even had time to process what is happening - the memory of whats happening can be stored in your cells. But what happens when these memories are stored in your cells - especially in areas like your fascia for years on end without being addressed? Often times it can lead to physical symptoms like headaches, back pain, neck pain, numbness and tingling and overall dysfunction. It can even negatively affect your posture.
This may be the part of reason why treating injuries from car accidents, emotional and physical assaults and childhood trauma can be so complex. Some of it is inevitably stored in the fascia and left to fester - it can lead to physical symptoms later on.
If you have suffered from any kind of emotional trauma, in addition to seeing a psychologist or psychotherapist I recommend seeing a manual therapist. This mind-body approach to healing can allow for more in depth recovery.