I woke up around 1:30 AM, with my left hip/lower back in enough pain that I couldn't sleep. I blind-walked downstairs to fetch ibuprofen, and on the way started to feel the muscle tension in my back, shoulders, and legs.
No doubt there is a large knowledge base regarding the relationship between (psychological) anxiety and muscle tension. The physiology of stress is fairly well understood by now, and we are learning more and more about the psychiatry and psychology of anxiety, PTSD, and depression.
I'm considering it phenomenologically, and especially the connection between these two analytically separated ideas -- psychological state on one side, physiological state on the other. The scientific discourses do separate these, as an initial step, and seek to explain one in terms of the other: anxiety issues and issues from physiological tension, as we are taught in anxiety-management classes. Is anxiety the shortness of breath, or is it the mental state? And so the discourse leads to a chicken-and-egg conclusion.
Phenomenologically, we'd want to begin by setting aside what we think we know about how bodies and psyches work, and work together. We should also set aside any presupposition about causality, and about the separateness or connectedness of the mental and physiological (while, I suppose, taking note of the implicit mind-body dualism of this approach).
My shoulders are bunched, half-shrugging, turned inward and downward, into my chest. This curves my back and arches my neck slightly, pushing my chin down toward my chest as well. The inwardness of this posture debilitates outward-stretching movements of my arms--reaching upward, to the side, to the front--, as well as loose swinging from the shoulders, as for instance when walking. It debilitates breathing. It hypersensitizes the skin and nervous response to any touch.
My upper torso is collapsing in on itself, the tension in my back stiffening it against anything that could come its way. I'm turtling (as the hockey expression goes), metaphorically meaning that my back is carapace-like, a shield. It is as if the tension creates the shell.
When I tried stretching, it was difficult to release the hold that it seemed this posture had over me. While it feels as though I'm in a shell, it's a shell that confines and restrains me, snaps back into place, snatches back my limbs. I had to struggle against the retraction of major muscle groups from head to toe. I braced against a wall and twisted to stretch my hip, and this motion was blocked by my glutes and hamstrings to the point I had to concentrate on undoing their tension.
I was fighting against this rigidity, my body's own rigidity, which I did not deliberate upon and direct. What I do deliberately in stretching, in "dropping" my shoulders, breathing slowly and deeply, sighing, and so on, works toward realigning and reorienting. But soon, the posture overtakes me again.
But I am this posture; that is, this posture is an embodied expression of my being-in-the-world. When shielded from whatever blows I might receive, I'm shielded from perceiving (psychoanalytically we might reverse that and say I'm shielded from being perceived, which is an interpretation with a nice Merleau-Pontyian reversibility to it). The range of my projection into the world is shortened like my breath; what I can do is constrained within the limits of the shell of musculature. The posture is anxiety. It is embodied, habituated trauma, which is to say that it reenacts trauma.
A body in pain is shaped by pain, and so expresses pain in posture and motion. The expression of pain is pain. To have been subjected by trauma, to be constituted by undergoing trauma as a traumatized subject, means to be orientated traumatically. The trauma goes on, carries itself forward through the projection and expression of this embodiment, and the world is a world for trauma -- a pre-traumatized world that finds its correlative in the traumatized body.