somatisation is huge aspect of PTSD, however; it is psychological distress based on bodily symptoms, which are caused by internal or external factors.
I read somatization differently - that it is psychological distress
manifesting as physical symptoms
Somatization is the expression of mental phenomena as physical (somatic) symptoms. Disorders characterized by somatization extend in a continuum from those in which symptoms develop unconsciously and nonvolitionally to those in which symptoms develop consciously and volitionally. This continuum includes somatic symptom and related disorders, factitious disorders, and malingering. In all of the disorders, patients focus prominently on somatic concerns. Thus, somatization typically leads patients to seek medical evaluation and treatment rather than psychiatric care.
Taken from The Merck Manual, professional version,
Overview of Somatization
So, the end result is not a mental symptom, but a physical one.
It is different from a flashback, in that the physical is not caused by a memory; it's only caused by a feeling. It's having a physical association with something in your mind, and I think with PTSD it would want to be on the unconscious and non-volitional end of the spectrum (as opposed to the conscious and volitional end, which is where we find factitious disorder, malingering, etc.)
I think the classic example is, I am anxious about a test I am taking later, and I have a stomach-ache. I don't have the pain because I didn't eat as a result of being nervous, or because I'm tired because I was up all night studying - there is no physical reason why I have the ache, it is purely a result of my feeling of anxiety.
I believe the 'heavy limb' phenomenon associated with depression would be a form of somatization, as well.
So, no physiological reason, including the body 'remembering' pain from the past. And that's where I get a little confused, because I used to think that those kinds of pains could be called somatic, but reading through this (and other) psych texts on somatization, somatoform disorder, etc...it seems like no, it needs to be mental phenomena creating physical symptoms.
?