Functional derivation · SBNFA™
Tissue adaptability
In the SBNFA™ framework, tissue adaptability refers to the functional capacity of tissues, particularly fascia, to change their mechanical configuration under stress, to redistribute that stress, to recover after unloading and to evolve over time without lastingly losing their capacity for deformation and gliding.
Scientific basis
Tissue adaptability is neither an elementary property nor a single measurement. It brings together several dimensions that are studied separately and do not act on the same time scale: – immediate: deformation, described by fascial viscoelasticity, and fascial gliding between layers; – short term: stress redistribution, to which local myofascial transmission contributes, and partial recovery after unloading; – long term: remodeling, through which mechanotransduction allows cells to adjust the extracellular matrix to the loads placed on them (Kjaer, 2004; Chiquet et al., 2009).
Remodeling is a gradual biological response that depends on the tissue, the intensity and repetition of stress, recovery, any inflammation, age and mechanical history. It does not mean that a change in posture automatically leads to a favorable transformation of the tissue.
Conversely, several alterations reduce some of these capacities, through distinct mechanisms: fascial stiffness, fascial densification, fascial adhesions or fascial fibrosis.
Blue Portance / SBNFA™ reading
The SBNFA™ links these dimensions in a functional sequence: tissues deform and glide under stress, redistribute part of the load, recover after unloading and may, over the longer term, change their organization in response to their mechanical environment. These phenomena overlap and influence one another; this is not an automatic chain.
Variability of loading is not movement for its own sake: it introduces alternations of loading and unloading and changes in the spatial distribution of stress. The framework posits that alternating loading with recovery periods may help maintain the capacity for tissue adaptation. This hypothesis is consistent with certain mechanical and biological properties of tissues, but it has not been validated as a specific effect of a seating device.
Contribution to the analysis of sitting
In sitting, the analysis does not measure tissue adaptability. It observes the mechanical conditions that can promote or limit adjustments: holding duration, fixity of support points, the possibility of changing configuration, alternation between loading and unloading, and the capacity to redistribute pressure.
An adaptable seat does not directly “restore” fascia: it provides an environment in which changes of configuration and variations in loading remain possible.
Not to be confused with
Adaptability, the integrative concept that answers the question “how does the body adjust its configuration and functioning?” and brings together the postural and tissue dimensions; postural adaptability, which answers “how does posture change according to the task and context?”; adaptive potential, which answers “what adjustment possibilities remain accessible?”; flexibility, the range of motion of a joint or muscle.
Sources and scope
- Kjaer (2004): role of the extracellular matrix in the adaptation of tendon and muscle to loading (Physiological Reviews)
- Chiquet et al. (2009): from mechanotransduction to matrix gene expression in fibroblasts (Biochim Biophys Acta)
- Yahia et al. (1993): viscoelastic properties of the human lumbodorsal fascia (J Biomed Eng)
operational concept of the SBNFA™ framework, built on documented tissue properties; it does not correspond to a single validated biomechanical or biological measurement, and any clinical benefits remain to be demonstrated.
Further reading
- Go further — Expert guide: Why Does Fascia Need Micro-Movements?
