Spinal Stenosis

«Understanding the condition (definition, symptoms, epidemiology, stages, absolute surgical indications)» slot — content in preparation.

«How surgery and SART complement each other» slot — content in preparation.

These are the evidence candidates assigned to this topic. The citations to be used are finalised by the author when the page is published.

• EV-050★★★★L2 · Randomised controlled trial / prospective cohort

  In low back pain the anticipatory (feedforward) activation of the deep stabilisers is delayed or lost

  Normally transversus abdominis and multifidus activate in advance of limb movement (feedforward) to lock the spine. In low back pain that anticipatory activation is delayed and the deep muscles become inhibited and atrophic.

  Hodges PW (1996) · Inefficient muscular stabilization of the lumbar spine (1996) and related work

• EV-004★★★L3 · Retrospective cohort / case-control / cross-sectional

  In spinal pain the deep stabilising muscles are neurologically inhibited and undergo structural change

  In low back pain patients the deep stabilisers such as multifidus show reduced cross-sectional area, fatty infiltration and neurological inhibition. Under fixation the brain's protective command drives the deep muscles into hypertonicity or loss of function (segmental facilitation).

  Korr IM; Hodges P et al. · Korr IM (segmental facilitation); Hodges P et al. (core stability, multifidus); MRI studies on multifidus fatty infiltration

  Limitation — Quantitative recent imaging papers (with PMIDs) on multifidus fatty infiltration still need to be added.

• EV-007★★★L3 · Retrospective cohort / case-control / cross-sectional

  Malalignment concentrates load on particular discs and drives degeneration

  Left–right asymmetry produces uneven loading of the vertebrae, which sets up a vicious cycle of muscle atrophy and overload leading to disc degeneration (cadaveric study). As sagittal malalignment increases, lumbar disc loading rises and deformity worsens in a self-reinforcing loop (musculoskeletal model). Alignment parameters such as pelvic incidence and sacral slope correlate with disc and facet pathology (systematic review).

  PMC12632278 (cadaveric); PMC9779485 (musculoskeletal model); PMC11959076 (systematic review) · PMC12632278 (cadaveric); PMC9779485 (musculoskeletal model); PMC11959076 (systematic review)

  Limitation — Bibliographic details still need to be confirmed.

• EV-059★★★L3 · Retrospective cohort / case-control / cross-sectional

  When whole-body sagittal alignment fails (as the back rounds), the autonomic nervous system becomes excited

  Standardised the sagittal alignment of the whole standing axial skeleton and proposed that malalignment is associated with autonomic excitation.

  Hasegawa K · Standing sagittal alignment of the whole axial skeleton

• EV-061★★★L3 · Retrospective cohort / case-control / cross-sectional

  Discs rehydrate and recover when load is reduced, but uncontrolled decompression is harmful

  Under the microgravity exposure of spaceflight, disc height and volume increase (rehydration), yet decompression that occurs rapidly and without control raises the risk of herniation and injury.

  Belavý DL (2016) · Disc herniations in astronauts (2016) and related work

• EV-064★★★L3 · Retrospective cohort / case-control / cross-sectional

  In the adult spine, overall sagittal balance governs symptoms more than curve magnitude

  Among radiographic parameters in adult spinal deformity, sagittal balance correlates most strongly with pain and functional disability — balance rather than angle.

  Glassman SD (2005) · Correlation of radiographic parameters

• EV-067★★★L3 · Retrospective cohort / case-control / cross-sectional

  Compressed it bends, distracted it straightens — the direction of load governs deformity

  Quantified the effect of immediate vertical unloading on spinal alignment and the disc, showing axial load to be a direct driver of deformity.

  Cheung JPY · The effect of immediate vertical unloading

• EV-070★★L4 · Cadaveric / biomechanical model / basic experiment

  Lumbar lordosis must be maintained for disc pressure to be distributed evenly

  A load-distribution model showing that when lumbar lordosis is maintained, pressure is spread evenly across the disc, and that when lordosis is lost, pressure concentrates in particular regions.

  Müller A (2021) · Load distribution in the lumbar spine

• EV-011★★L4 · Cadaveric / biomechanical model / basic experimentfoundational

  The body negotiates with gravity, and when sagittal alignment fails the body leaves that efficient range and energy cost rises steeply

  The efficient range within which upright stance is maintained is defined as the Cone of Economy. When sagittal alignment (pelvic incidence, sacral slope and related parameters) breaks down, the body falls outside that cone, muscular energy cost rises sharply, and pain and deformity follow.

  Dubousset J; Schwab F (2006) · Dubousset J (cone of economy); Schwab F et al., adult spinal deformity alignment parameters

• EV-029★★L4 · Cadaveric / biomechanical model / basic experimentfoundational

  The lumbar spine is damaged by repeated flexion and torsion, and neutral must be preserved

  An injured lumbar spine is made worse by repeated flexion and extension and by cumulative load (spine sparing). The combination of flexion and torsion is central to annular damage.

  McGill S (2002) · Low Back Disorders

• EV-077★★L4 · Cadaveric / biomechanical model / basic experimentfoundational

  The pressure borne by the disc varies markedly with posture (sitting exceeds standing)

  Direct in vivo measurement of lumbar intradiscal pressure across postures. Sitting — and especially sitting in forward flexion — raises disc pressure substantially above standing.

  Nachemson A (1960) · Lumbar intradiscal pressure