Non-Specific Low Back Pain: An Adaptive–Sensitized Model
Author: Roger García
Degree in Physiotherapy and Rehabilitation
Abstract
Non-specific low back pain is a complex phenomenon arising from the interaction between biomechanical adaptations, cumulative tissue dysfunctions, and central nervous system sensitization.
This model proposes that pain is neither random nor purely central, but rather reflects a historical adaptive process of the body to loading and movement patterns. Pain persistence is explained by secondary hypersensitization, modulated by prior experiences, overprotection, and psychosocial factors.
This approach provides a useful conceptual framework for patient evaluation, treatment, and education.
Introduction
Non-specific low back pain accounts for approximately 85–90% of low back pain cases in the general population. It has traditionally been classified as “non-specific” due to the difficulty of identifying a clearly injured tissue through clinical examination or imaging studies.
However, evidence suggests that an initial structural dysfunction does exist, even if microscopic or functional in nature. Adaptations to repetitive movement patterns or sedentary behavior increase the risk of overload, while central nervous system sensitization explains the persistence of pain—even when the structure has partially recovered.
Model Foundations
Postural Development and Evolutionary Biomechanics
The human spine develops critical curvatures throughout growth: an initial single fetal kyphosis, followed by cervical lordosis with head control, and lumbopelvic lordosis with the onset of bipedalism.
These curvatures enable load distribution and stability through the thoracolumbar fascia. Pain emerges when sudden exposure to movements outside the adaptive range produces microdamage and overload.
Tissue Irritability and Sensitization
Initial tissue damage leads to altered local motor control, increased tone in deep musculature, and low-grade local inflammation.
Repeated exposure to these stimuli lowers the nociceptive threshold, amplifying pain perception and generating lumbar hypervigilance. Sensitization does not create pain—it sustains it, without implying that the pain is imaginary.
Factors such as stress, fear of movement, and prior experiences modulate its intensity.
Clinical and Therapeutic Integration
Low back pain is understood as the interaction between structural adaptation, tissue microdamage, and hypersensitization.
Management should be multi-level:
- Peripheral Level: Restore load tolerance and improve movement variability
- Central Level: Pain education, gradual re-exposure to movement, and reduction of hypervigilance
Conclusion
Non-specific low back pain results from structural and functional adaptations that generate initial tissue irritability. Its persistence is maintained by secondary sensitization, modulated by lifestyle habits and psychosocial factors.
This reinforces the concept that pain is a real biological response—not a purely central or imagined phenomenon.
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García R. Non-specific low back pain: an adaptive–sensitized model integrating biomechanics, development, and neurophysiology. 2026.
