Static mechanical allodynia (sma)
Concept: its essence, its literal meaning (glossary) and its universe of meanings (polysemy). In Fall of 2021, the Method of Somatosensory Pain Rehabilitation (SPR) Department has formed:
the interdisciplinary, intercontinental and intergenerational
Terminology Interest Group.
CSTP©, STP, neurologist, physiotherapist, occupational therapist,
anatomist, citizen and so on.
who will, volume after volume, offer you fact sheets that put concepts of the RSD method into perspective.
To get you started, we have selected a set of terms that are listed in the Manual’s and Atlas’ glossaries. These concepts best describe the specificity of the RSD method. We began with neuralgia in Somatosens Pain Rehab 20(4). Here is a second concept in English:
static mechanical allodynia
Patients will rarely arrive with a precise medical diagnosis of static mechanical allodynia. However, we must be on the lookout for this somatosensory disorder, which often occur following many medical procedures. Patients will show up in the middle of winter wearing sandals or a short-sleeved shirt. They may describe their sensation to the touch as “burning,” “stinging,” or “radiant.” They may describe sensations to the touch as “burning,” “stinging” or “radiating.” They try to compare their sensations to their experiences: a cook will not refer to their pain to the touch as “allodynia,” but rather as "if boiling oil were being poured constantly on my hand." During sessions, they will avoid touching the affected limb and may be unable to tolerate heat or ice, massage and/or the simple touch of your hands. Intuitively, when patients describe these symptoms and/or act in this way, we suspect a static mechanical allodynia. (Spicher et al., 2025) – another pain. The prefix αλλος |allo-| signifies ‘other’, while the suffix οδυνη | -odynia | refers to pain.
Definition Pain evoked by a static mechanical stimulus that normally does not evoke pain, following axonal lesions of Aβ neurofibers. This is NOT dynamic mechanical allodynia (C nerve fibers).
A bit of history In 1973, Harold Merskey was appointed chair of the Terminology committee of the International Association for the Study of Pain. In 1979, hyperesthesia was abolished in order to distinguish between the mechanisms of: (1) allodynia, (2) hyperalgesia and (3) secondary hyperalgesia.
Physiological reality and objective clinical examination signs SMA is a HYPO-esthesia that is paradoxically painful to the touch (de Andrade Melo Knaut et al., Douleur analg 2024). The core of this hypersensitivity to touch is located on top of a hypoesthetic territory caused by lesions of Aβ neurofibers. Throughout the day – and with provoked contact – it spreads like a tidal wave – extent of allodynia (Llewellyn et al., PAIN® 2023). These lesions of a few fibers in a cutaneous nerve branch cause a disruption of the somatosensory nervous system: (1) biochemical modulations in the spinal cord – known in neuroscience as spinal sensitization – and (2) increased activity in the amygdala, the center of learned fear. Allodynography and Rainbow Pain Scale are standardized clinical examination signs that allow us to objectify the expression of these physiological mechanisms. When a skin injury occurs, to allow for scarring to occur, an ‘allodynia of scarring’ develops. Unfortunately, in some patients, it persists after the 10th day. Thus, the goal of the method of Somatosensory Pain Rehabilitation is to restore this tactile-pain inhibition. This is a high evidence-based treatment (Packham et al., 2018; Griffiths et al., 2023).
Summary A very common symptom (40% of neuralgia cases; n=4995), which temporarily generates countless situations of disability, is illogical – contradictory – paradoxical, but very real.
In a non-exhaustive way, we should continue our work with the following concepts (in no particular order):
Somatosensory nervous system
Adaptive neuroplasticity
Rainbow pain scale
Distant tactile counterstimulation
Paradoxical painful to touch Hypo-aesthesia
Largest territory of cutaneous origin
Complex regional pain syndrome of Budapest
SRP method.
