Functional model · SBNFA™
Nerve mechanical tolerance
In the SBNFA™ framework, nerve mechanical tolerance refers to the presumed functional capacity of a nerve and its surroundings to tolerate certain combinations of tension, compression, gliding and duration without triggering or worsening symptoms.
Scientific basis
Peripheral nerves have documented mechanosensitivity and capacity to adapt to movement: they glide, elongate and respond to compression according to thresholds that vary with the intensity and duration of the load (Topp and Boyd 2006; Rempel, Dahlin and Lundborg 1999). Neurodynamics studies these properties (Coppieters and Butler 2008).
There is no validated measure of an overall "nerve mechanical tolerance": the term brings together properties that are documented separately.
Blue Portance / SBNFA™ reading
Nerve mechanical tolerance is an SBNFA™ functional model based on separately documented mechanisms. It describes a presumed functional capacity that depends on both the nerve and its surroundings.
Contribution to the analysis of sitting
Seating analysis does not measure nerve mechanical tolerance. It describes the mechanical conditions (pelvic orientation, duration and variation of support) under which this capacity is called upon. It cannot diagnose nerve compression or locate the origin of pain.
Not to be confused with
Nerve compression, a load applied to the nerve by neighboring structures; Nerve gliding, the movement of the nerve relative to its interfaces; Peripheral sensitization, a lowering of the nociceptor threshold; Pain threshold, the minimum intensity of a stimulus perceived as painful.
Related terms
Nerve compression · Nerve gliding · Peripheral sensitization · Pudendal nerve · Adaptive reserve · Prolonged sitting intolerance
Sources and scope
- Topp and Boyd (2006): structure and biomechanics of peripheral nerves, responses to physical stresses (Physical Therapy)
- Rempel, Dahlin and Lundborg (1999): pathophysiology of nerve compression syndromes, response of peripheral nerves to loading (Journal of Bone and Joint Surgery Am)
- Coppieters and Butler (2008): analysis of neurodynamic sliding and tensioning techniques (Manual Therapy)
An SBNFA™ functional model, not validated as a clinical entity. It is not a validated measure; no tolerance threshold is objectively measurable, and it refers neither to a "fragile nerve" nor to a "pinched nerve".
Further reading
- Learn more — Article: Pudendal Neuralgia: Why Can a Simple Sitting Position Become an Ordeal?
- Go further — Expert guide: Functional Anatomy and Neuromechanics of the Pudendal Nerve
