{"id":8244,"date":"2026-10-14T20:35:57","date_gmt":"2026-10-14T18:35:57","guid":{"rendered":"https:\/\/blueportance.com\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/measurement-validation\/"},"modified":"2026-10-25T22:44:13","modified_gmt":"2026-10-25T21:44:13","slug":"measurement-validation","status":"publish","type":"page","link":"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/measurement-validation\/","title":{"rendered":"KB 3_Expert Guide_02_Living Flows_03_Adaptability Potential_05_From Expert Evaluation to Instrumented Measurement"},"content":{"rendered":"\n\n<!-- KB 3 \u00b7 SBNFA expert dossier (US) \u00b7 05-metrology-validation.html \u00b7 source iCloud Dossier expert SBNFA US (5\/10\/2026) -->\n<nav aria-label=\"Dossier chapters\" class=\"bp-dossier-nav\"><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/\">Pillar<\/a><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/living-system\/\">1 \u00b7 From Fixed Mechanism to Living System<\/a><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/foundational-principles\/\">2 \u00b7 Four Foundational Principles<\/a><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/functional-evaluation-grid\/\">3 \u00b7 Seven Functions, Nineteen Variables<\/a><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/dynamic-chair-benchmark\/\">4 \u00b7 Product Benchmark: A Dated Application of the Framework<\/a><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/measurement-validation\/\">5 \u00b7 From Expert Evaluation to Instrumented Measurement<\/a><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/glossary-bibliography\/\">6 \u00b7 Appendices, Glossary, and Bibliography<\/a><\/nav>\n<article class=\"bp-satellite\">\n<header>\n<p class=\"bp-meta\">SBNFA\u2122 Dossier \u00b7 Version 1.1 of <time datetime=\"2026-10-05\">October 5, 2026<\/time><br\/>Gil Ayache, PhD \u2014 Mines Paris \u2013 PSL \u00b7 Cofounder and President of Blue Portance<\/p>\n<h1>From Expert Evaluation to Instrumented Measurement<\/h1>\n<\/header><aside aria-label=\"Claim statuses\" class=\"bp-status\"><h2>Reading the statuses<\/h2><p>The labels <strong>[ESTABLISHED]<\/strong>, <strong>[MECHANICAL]<\/strong>, <strong>[SBNFA PROPOSITION]<\/strong> and <strong>[OUTLOOK]<\/strong> indicate the nature of each claim. They are defined on the <a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/#statuts\">dossier home page<\/a>.<\/p><\/aside>\n<section class=\"bp-summary\">\n<p class=\"bp-answer\"><strong>In brief.<\/strong> What does this evaluation actually measure? The capabilities a seating architecture offers the body. Level 1 establishes them through multi-criteria analysis of technical specifications, user feedback and expert judgment; Level 2 aims to quantify them through 3D kinematics, pressure mapping, mechanical threshold measurement and electromyography.<\/p>\n<p>This fifth chapter describes the transition from the scientific foundation of the SBNFA\u2122 framework to its instrumental testing: a completed Level 1 multi-criteria analysis, and a Level 2 that aims to quantify the variables objectively and test the reproducibility of ratings, through a dedicated instrumental program.<\/p>\n<p>It sets out what Level 1 can and cannot do, what Level 2 will make it possible to verify, the limitations of Level 1 and the responses provided, an evidence scale for situating each claim, and the avenues for discussion open to third parties.<\/p>\n<\/section>\n<nav aria-label=\"Contents\" class=\"bp-toc\"><h2>Contents<\/h2><ol><li><a href=\"#introduction\">Introduction<\/a><\/li><li><a href=\"#section-1\">1. From Scientific Foundation to Instrumental Testing<\/a><\/li><li><a href=\"#section-2\">2. Two Levels of Evaluation<\/a><\/li><li><a href=\"#section-3\">3. What Level 1 Can and Cannot Do<\/a><\/li><li><a href=\"#section-4\">4. Toward Level 2: Measurement Avenues by Variable<\/a><\/li><li><a href=\"#section-5\">5. Proposed Instrumental Program and Implementation Conditions<\/a><\/li><li><a href=\"#section-6\">6. What Level 2 Will Make It Possible to Verify<\/a><\/li><li><a href=\"#section-7\">7. Limitations of Level 1 and the Responses Provided<\/a><\/li><li><a href=\"#section-8\">8. An Evidence Scale for Situating Each Claim<\/a><\/li><li><a href=\"#section-9\">9. Scientific Discussion and Application by Third Parties<\/a><\/li><li><a href=\"#section-10\">10. Outlook<\/a><\/li><li><a href=\"#faq\">Frequently Asked Questions<\/a><\/li><li><a href=\"#references\">References<\/a><\/li><\/ol><\/nav>\n<section class=\"bp-section\" id=\"introduction\">\n<h2>Introduction<\/h2>\n<p class=\"bp-lead\">The SBNFA\u2122 framework draws on documented phenomena and translates them into a constructed grid. A first application, by multi-criteria analysis, has been carried out (<a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/dynamic-chair-benchmark\/\">benchmark of six dynamic seats<\/a>, Chapter 4); validation of the model remains open. This fifth chapter describes the next step: Level 2, which aims to <strong>quantify the variables objectively and test the reproducibility of ratings<\/strong>.<\/p>\n<p><strong>[OUTLOOK]<\/strong> Instrumental testing must be able to challenge the relevance of the functions and variables, their boundaries and their anchors, as much as their correspondence with measurements. It tests an SBNFA construct, without conflating this validation with that of the phenomena already documented.<\/p>\n<p>This is also the chapter that answers the question put to any company that publishes a benchmark including its own product: how is this work anything other than a sales argument? The answer rests on three elements: criteria grounded in knowledge independent of Aporia\u00ae, declared limitations, and avenues for discussion and measurement open to third parties.<\/p>\n<\/section>\n<section class=\"bp-section\" id=\"section-1\">\n<h2>1. From Scientific Foundation to Instrumental Testing<\/h2>\n<p class=\"bp-lead\">The framework follows a classic scientific path, and each step has its own stage of completion.<\/p>\n<div class=\"bp-table-wrap\"><table>\n<thead>\n<tr><th>Step<\/th><th>Content<\/th><th>Status<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>1. Scientific foundation<\/strong><\/td><td>Biomechanical, neuromotor and tissue knowledge on which the four principles rest (Chapter 2)<\/td><td>Completed<\/td><\/tr>\n<tr><td><strong>2. Model construction<\/strong><\/td><td>Chain of principles, functions, requirements, variables; seven functions (Chapters 1 to 3)<\/td><td>Completed<\/td><\/tr>\n<tr><td><strong>3. Operationalization<\/strong><\/td><td>Nineteen state variables, 0-to-4 scale, anchors, boundary rules (Chapter 3)<\/td><td>Completed<\/td><\/tr>\n<tr><td><strong>4. Observables and evaluation<\/strong><\/td><td>Multi-criteria analysis of six devices using the grid (Chapter 4)<\/td><td>Completed \u2014 Level 1<\/td><\/tr>\n<tr><td><strong>5. Instrumental testing<\/strong><\/td><td>Measurement of the variables, reproducibility of ratings<\/td><td>[OUTLOOK] Dedicated instrumental program<\/td><\/tr>\n<\/tbody>\n<\/table><\/div>\n<div class=\"bp-key-message\">\n<p><strong>[OUTLOOK]<\/strong> Level 2 will put the model and its ratings to the test. The results may require revision of the variables, anchors or aggregation rules; the literature does not guarantee their metrological validity in advance.<\/p>\n<\/div>\n<\/section>\n<section class=\"bp-section\" id=\"section-2\">\n<h2>2. Two Levels of Evaluation<\/h2>\n<p class=\"bp-lead\">The framework is designed for two successive levels of use, without altering its functional logic [<a href=\"#ref-1\">1<\/a>].<\/p>\n<div class=\"bp-table-wrap\"><table>\n<thead>\n<tr><th>Criterion<\/th><th>Level 1 \u2014 Multi-criteria analysis<\/th><th>Level 2 \u2014 Instrumented scientific evaluation<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Horizon<\/strong><\/td><td>Short term<\/td><td>Medium term<\/td><\/tr>\n<tr><td><strong>Method<\/strong><\/td><td>Multi-criteria grid applied to technical specifications, documentation, user feedback and expert judgment<\/td><td>Each variable is progressively associated with a measurement method, a unit and an experimental protocol<\/td><\/tr>\n<tr><td><strong>Tools<\/strong><\/td><td>Observation, manual loading, architectural and documentary analysis<\/td><td>3D kinematics, pressure mapping, measurement of mechanical thresholds, EMG, tissue measurements<\/td><\/tr>\n<tr><td><strong>What it enables<\/strong><\/td><td>Comparing architectures against the same criteria; identifying capabilities offered and restrictions<\/td><td>Objectively establishing the state of a variable through measured, reproducible quantities<\/td><\/tr>\n<tr><td><strong>Status<\/strong><\/td><td>Completed for six devices<\/td><td>[OUTLOOK] Dedicated instrumental program<\/td><\/tr>\n<\/tbody>\n<\/table><\/div>\n<p>In both cases, the framework remains independent of the technical solutions evaluated. A Level 1 evaluation is not an approximate version of Level 2: it serves a different purpose, which is to structure the questions, identify the capabilities to be measured and compare architectures before the budget for an instrumented protocol is committed.<\/p>\n<\/section>\n<section class=\"bp-section\" id=\"section-3\">\n<h2>3. What Level 1 Can and Cannot Do<\/h2>\n<p class=\"bp-lead\">Level 1 evaluation relies on observing architectures and how they function, using a grid, criteria and conditions identical for all devices. It produces profiles, not measurements.<\/p>\n<div class=\"bp-table-wrap\"><table>\n<thead>\n<tr><th>What Level 1 can do<\/th><th>What it cannot do<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Describe what an architecture allows or constrains: direction, range, coupling, return, independence<\/strong><\/td><td>Quantify a range of travel, a return force or a pressure with a known uncertainty<\/td><\/tr>\n<tr><td><strong>Compare devices on the same variables and detect differing profiles<\/strong><\/td><td>Draw conclusions from a difference of a few hundredths between two scores<\/td><\/tr>\n<tr><td><strong>Detect restrictions and record them with their justification<\/strong><\/td><td>Establish an effect on perfusion, pain, fatigue or health<\/td><\/tr>\n<tr><td><strong>Structure the questions to be measured next<\/strong><\/td><td>Replace an instrumented scientific evaluation<\/td><\/tr>\n<\/tbody>\n<\/table><\/div>\n<div class=\"bp-key-message\">\n<p><strong>[MECHANICAL]<\/strong> Level 1 describes observable architectural properties. It establishes no biological or clinical effect: any statement that extends a Level 1 score into a promise of benefit for the user falls outside the scope of the framework.<\/p>\n<\/div>\n<\/section>\n<section class=\"bp-section\" id=\"section-4\">\n<h2>4. Toward Level 2: Measurement Avenues by Variable<\/h2>\n<p class=\"bp-lead\">The framework specifies that each variable will be associated with a measurement method, a unit and a protocol. The indicators it adopts to objectively establish the state of a variable \u2014 range, threshold, dead zone, hysteresis, left\/right independence, continuity of response, pressure mapping, residual displacement \u2014 carry no score of their own: they serve to document the observed state [<a href=\"#ref-1\">1<\/a>].<\/p>\n<p>The following table suggests, as avenues to explore, the family of measurements that could correspond to each group of variables. <strong>[OUTLOOK]<\/strong> This is not a finalized protocol: each avenue has yet to be turned into a protocol.<\/p>\n<div class=\"bp-table-wrap\"><table>\n<thead>\n<tr><th>Variables<\/th><th>Quantity to be objectified<\/th><th>Possible measurement family<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>ADP-2, INF-3<\/strong><\/td><td>Activation threshold, dead zone, hysteresis, progressiveness of the response to low-level loading<\/td><td>Measurement of mechanical thresholds on a test bench and on subjects<\/td><\/tr>\n<tr><td><strong>ADP-1, MOB-1 to MOB-3, COM-1, COM-2<\/strong><\/td><td>Pelvic and spinal trajectories in all three planes; role of the subject or the seat in initiating movement<\/td><td>3D kinematics<\/td><\/tr>\n<tr><td><strong>EQU-1, EQU-2<\/strong><\/td><td>Left\/right independence; extent of the space within which stopping and stable holding remain possible<\/td><td>3D kinematics, pressure mapping<\/td><\/tr>\n<tr><td><strong>CON-1, CON-2, PRE-3<\/strong><\/td><td>Distribution and temporal redistribution of pressure; load\u2013offload alternation<\/td><td>Pressure mapping<\/td><\/tr>\n<tr><td><strong>INF-1, INF-2, PRE-1, PRE-2<\/strong><\/td><td>Reproducibility of the response; preservation of the local origin; local relative movements<\/td><td>Localized displacement measurements, pressure mapping<\/td><\/tr>\n<tr><td><strong>EQU-2, ADP (control cost)<\/strong><\/td><td>Muscle activation associated with holding and moving<\/td><td>Electromyography<\/td><\/tr>\n<tr><td><strong>PRE (tissue effects)<\/strong><\/td><td>Gliding, perfusion, deformation<\/td><td>Tissue measurements \u2014 whose biological effect requires separate evidence<\/td><\/tr>\n<\/tbody>\n<\/table><\/div>\n<p>Instrumented studies already exist on related quantities: muscle activation, physical activity and posture when using dynamic chairs [<a href=\"#ref-2\">2<\/a>], lumbar activation and posture on an unstable surface [<a href=\"#ref-3\">3<\/a>], and intradiscal pressure in standing and sitting [<a href=\"#ref-4\">4<\/a>]. Movement variability is the subject of nonlinear analysis methods [<a href=\"#ref-5\">5<\/a>]. These studies show that the protocols exist, and they will serve as methodological references.<\/p>\n<\/section>\n<section class=\"bp-section\" id=\"section-5\"><h2>5. Proposed Instrumental Program and Implementation Conditions<\/h2><p><strong>[OUTLOOK]<\/strong> Measurements are planned with a university biomechanics laboratory starting in 2027.<\/p><p>Before the study, the following must be specified: the devices and settings, the population or mechanical setup, the loading conditions, the repetition of trials, the quantities and units, calibration, uncertainty, the analysis strategy and the criteria for conclusions. Mechanical measurements, sensorimotor observations and biological responses require separate protocols.<\/p><p>Evaluators will need explicit anchors and comparable records. A measurement validates a variable only if the correspondence between the definition, the observable and the measured quantity is justified. Contradictory or inconclusive results must remain visible.<\/p><\/section>\n<section class=\"bp-section\" id=\"section-6\">\n<h2>6. What Level 2 Will Make It Possible to Verify<\/h2>\n<p class=\"bp-lead\">Level 2 addresses specific questions, which concern objective quantification rather than the discovery of a foundation.<\/p>\n<div class=\"bp-table-wrap\"><table>\n<thead>\n<tr><th>Subject<\/th><th>Question addressed at Level 2<\/th><th>Contribution<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Rating\u2013measurement correspondence<\/strong><\/td><td>Does the expert rating of a variable correspond to the measured quantities (thresholds, trajectories, pressures)?<\/td><td>Calibrate the 0-to-4 anchors against quantified values<\/td><\/tr>\n<tr><td><strong>Reproducibility<\/strong><\/td><td>Do two evaluators rate the same device in the same way?<\/td><td>Document inter-rater reliability and refine the anchors<\/td><\/tr>\n<tr><td><strong>Extent of capabilities<\/strong><\/td><td>What is the measured extent of the stabilized space, of pelvic mobility, of left\/right independence?<\/td><td>Replace indicative values (for example the cone estimated at approximately \u00b145\u00b0) with measured values<\/td><\/tr>\n<tr><td><strong>Discrimination<\/strong><\/td><td>Does the grid distinguish between different architectures, including non-segmented ones?<\/td><td>Test discriminant capacity and technological neutrality<\/td><\/tr>\n<tr><td><strong>Differences between variables<\/strong><\/td><td>Are neighboring variables (ADP-2 and INF-3, CON-2 and PRE-3) distinguishable in the measurements?<\/td><td>Consolidate the boundary rules<\/td><\/tr>\n<\/tbody>\n<\/table><\/div>\n[OUTLOOK] These verifications must put the SBNFA construct to the test: they may lead to revising the variables or their anchors. The scientific documentation of the phenomena does not prejudge their metrological relevance.<\/p>\n<\/section>\n<section class=\"bp-section\" id=\"section-7\">\n<h2>7. Limitations of Level 1 and the Responses Provided<\/h2>\n<p class=\"bp-lead\">Level 1 has its own limitations, which explain the role of Level 2.<\/p>\n<div class=\"bp-table-wrap\"><table>\n<thead>\n<tr><th>Level 1 limitation<\/th><th>Current response<\/th><th>Planned next step<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Expert evaluation: the rating depends on the evaluator<\/strong><\/td><td>Anchors for each variable; data collection table justifying the state adopted and the higher state rejected; fully-demonstrated-level rule<\/td><td>Inter-rater reproducibility testing (Level 2)<\/td><\/tr>\n<tr><td><strong>Evaluator linked to one of the devices evaluated<\/strong><\/td><td>Declaration of interests; same criteria and same rating rules for all<\/td><td>Application of the grid by third-party evaluators<\/td><\/tr>\n<tr><td><strong>Sample of six devices<\/strong><\/td><td>Systematic market scan; five representative architectures selected<\/td><td>Possible extension to other families of seating<\/td><\/tr>\n<tr><td><strong>Heterogeneous documentary basis<\/strong><\/td><td>Difference flagged<\/td><td>Harmonization through measurement<\/td><\/tr>\n<tr><td><strong>Equal weighting of functions<\/strong><\/td><td>Convention for readability; profile-based reading takes priority over the score<\/td><td>Discussion of possible weightings during revisions<\/td><\/tr>\n<tr><td><strong>Ordinal scale<\/strong><\/td><td>Profile-based reading rather than score-based<\/td><td>Anchors quantified through measurement<\/td><\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/section>\n<section class=\"bp-section\" id=\"section-8\">\n<h2>8. An Evidence Scale for Situating Each Claim<\/h2><figure class=\"bp-figure\"><svg aria-label=\"Five types of claim and the evidence required for each.\" role=\"img\" style=\"display:block;width:100%;height:auto\" viewbox=\"0 0 1200 970\" xml:lang=\"en\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><title>Which claim, which evidence?<\/title><rect fill=\"#faf9f5\" height=\"970\" width=\"1200\"><\/rect><g font-family=\"Arial, sans-serif\"><text fill=\"#146c70\" font-size=\"15\" font-weight=\"700\" x=\"48\" y=\"60\">SBNFA\u2122  \/  EXPERT DOSSIER<\/text><text fill=\"#18363c\" font-size=\"32\" font-weight=\"700\" x=\"48\" y=\"108\">Which claim, which evidence?<\/text><rect fill=\"#e9f2eb\" height=\"124\" rx=\"12\" stroke=\"#cddbd6\" width=\"1104\" x=\"48\" y=\"158\"><\/rect><text fill=\"#146c70\" font-size=\"38\" font-weight=\"700\" x=\"76\" y=\"228\">A<\/text><text fill=\"#18363c\" font-size=\"15\" font-weight=\"700\" x=\"148\" y=\"187\">[ESTABLISHED]<\/text><text fill=\"#18363c\" font-size=\"24\" font-weight=\"700\" x=\"148\" y=\"220\">Scientific phenomenon<\/text><text fill=\"#18363c\" font-size=\"18\" font-weight=\"400\" x=\"148\" y=\"252\">Cited literature; explicit population, context and limits.<\/text><rect fill=\"#edf0fa\" height=\"124\" rx=\"12\" stroke=\"#cddbd6\" width=\"1104\" x=\"48\" y=\"300\"><\/rect><text fill=\"#146c70\" font-size=\"38\" font-weight=\"700\" x=\"76\" y=\"370\">B<\/text><text fill=\"#18363c\" font-size=\"15\" font-weight=\"700\" x=\"148\" y=\"329\">[SBNFA PROPOSITION]<\/text><text fill=\"#18363c\" font-size=\"24\" font-weight=\"700\" x=\"148\" y=\"362\">Translation for seating<\/text><text fill=\"#18363c\" font-size=\"18\" font-weight=\"400\" x=\"148\" y=\"394\">Functions, variables, anchors and relationships proposed by the model.<\/text><rect fill=\"#e7f1f3\" height=\"124\" rx=\"12\" stroke=\"#cddbd6\" width=\"1104\" x=\"48\" y=\"442\"><\/rect><text fill=\"#146c70\" font-size=\"38\" font-weight=\"700\" x=\"76\" y=\"512\">C<\/text><text fill=\"#18363c\" font-size=\"15\" font-weight=\"700\" x=\"148\" y=\"471\">[MECHANICAL]<\/text><text fill=\"#18363c\" font-size=\"24\" font-weight=\"700\" x=\"148\" y=\"504\">Capacity of an architecture<\/text><text fill=\"#18363c\" font-size=\"18\" font-weight=\"400\" x=\"148\" y=\"536\">Traceable observation; configuration, restrictions and coverage.<\/text><rect fill=\"#fbf0df\" height=\"124\" rx=\"12\" stroke=\"#cddbd6\" width=\"1104\" x=\"48\" y=\"584\"><\/rect><text fill=\"#146c70\" font-size=\"38\" font-weight=\"700\" x=\"76\" y=\"654\">D<\/text><text fill=\"#18363c\" font-size=\"15\" font-weight=\"700\" x=\"148\" y=\"613\">[TO BE VALIDATED]<\/text><text fill=\"#18363c\" font-size=\"24\" font-weight=\"700\" x=\"148\" y=\"646\">Instrumented quantity<\/text><text fill=\"#18363c\" font-size=\"18\" font-weight=\"400\" x=\"148\" y=\"678\">Protocol, units, calibration, uncertainty and reproducibility.<\/text><rect fill=\"#fbf0df\" height=\"124\" rx=\"12\" stroke=\"#cddbd6\" width=\"1104\" x=\"48\" y=\"726\"><\/rect><text fill=\"#146c70\" font-size=\"38\" font-weight=\"700\" x=\"76\" y=\"796\">E<\/text><text fill=\"#18363c\" font-size=\"15\" font-weight=\"700\" x=\"148\" y=\"755\">[TO BE VALIDATED]<\/text><text fill=\"#18363c\" font-size=\"24\" font-weight=\"700\" x=\"148\" y=\"788\">Use or clinical effect<\/text><text fill=\"#18363c\" font-size=\"18\" font-weight=\"400\" x=\"148\" y=\"820\">Separate study, with suitable population and outcome criteria.<\/text><text fill=\"#18363c\" font-size=\"20\" font-weight=\"700\" x=\"48\" y=\"912\">Each claim requires its own evidence: no automatic step from one level to the next.<\/text><\/g><\/svg><figcaption>Figure 3 \u2014 Five types of claim and the evidence required for each.<\/figcaption><\/figure>\n<p class=\"bp-lead\">To situate a claim, one need only know which rung of an evidence scale it rests on.<\/p>\n<div class=\"bp-table-wrap\"><table>\n<thead>\n<tr><th>Type of claim<\/th><th>Nature<\/th><th>Where to find it<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>A \u2014 Scientific foundation<\/strong><\/td><td>Knowledge from biomechanics, motor control, tissue physiology (<strong>[ESTABLISHED]<\/strong>)<\/td><td>Chapters 2 and 3<\/td><\/tr>\n<tr><td><strong>B \u2014 Translation to seating<\/strong><\/td><td>Requirements and variables constructed from this knowledge (<strong>[SBNFA PROPOSITION]<\/strong>)<\/td><td>Chapters 1 to 3<\/td><\/tr>\n<tr><td><strong>C \u2014 Evaluation of architectures<\/strong><\/td><td>Comparative observation, common grid, Level 1 (<strong>[MECHANICAL]<\/strong>)<\/td><td>Chapter 4<\/td><\/tr>\n<tr><td><strong>D \u2014 Instrumented measurements<\/strong><\/td><td>Kinematics, pressure, thresholds, EMG, tissue measurements (<strong>[OUTLOOK]<\/strong>)<\/td><td>[OUTLOOK] Program planned starting in 2027<\/td><\/tr>\n<tr><td><strong>E \u2014 Usage and clinical studies<\/strong><\/td><td>Effects on pain, fatigue and health, at population level<\/td><td>Outside the scope of this dossier<\/td><\/tr>\n<\/tbody>\n<\/table><\/div>\n<div class=\"bp-key-message\">\n<p>This dossier covers claims A to C and prepares for D. It asserts nothing that falls under E: any clinical promise would exceed its scope.<\/p>\n<\/div>\n<\/section>\n<section class=\"bp-section\" id=\"section-9\">\n<h2>9. Scientific Discussion and Application by Third Parties<\/h2>\n<p class=\"bp-lead\">The framework is designed to be applied by a third party: its criteria are independent of the solutions evaluated, each variable has its anchors, each score must be justified, and so must the rejection of the higher state.<\/p>\n<p>Four types of contribution are possible, and useful:<\/p>\n<ul class=\"bp-list-functions\">\n<li><strong>challenging a score<\/strong>: showing, through observation or measurement, that a higher or lower state is or is not fully demonstrated;<\/li>\n<li><strong>refining a variable<\/strong>: proposing a more precise definition, anchor or boundary rule;<\/li>\n<li><strong>expanding the sources<\/strong>: contributing studies that better document a foundation or its application to seating;<\/li>\n<li><strong>applying the grid to another device<\/strong>: this is the best way to test its discriminant capacity and technological neutrality.<\/li>\n<\/ul>\n<p>The framework stipulates that any change to a monograph is carried over into the summary documents, the radar chart and the consolidation workbook, so that a correction leaves no inconsistency behind [<a href=\"#ref-6\">6<\/a>]. Blue Portance welcomes well-argued contributions.<\/p>\n<p>The distinction between a method audit and a product-doctrine audit described in Chapter 1 applies here: conclusions about a product and conclusions about the model must be argued separately. A product observation may nonetheless reveal a methodological weakness and lead to an explicit revision of the framework.<\/p>\n<\/section>\n<section class=\"bp-section\" id=\"section-10\">\n<h2>10. Outlook<\/h2>\n<p class=\"bp-lead\">[OUTLOOK] The next steps test the SBNFA construct against independent observations and measurements.<\/p>\n<ul class=\"bp-list-functions\">\n<li>Consider extending the sample to other families of seating, including static and synchronous chairs, without changing the functional logic of the framework.<\/li>\n<li>Confirm partners and timeline, finalize a protocol, then test each variable against the measured quantities.<\/li>\n<li>Extend application of the grid to third-party evaluators and test the reproducibility of ratings.<\/li>\n<li>Revise the framework through dated versions as measurements refine the anchors.<\/li>\n<\/ul>\n<p>The framework is also designed to evaluate other technologies: Aporia\u00ae is only its first application. A future device from another manufacturer that offers capabilities described by the grid will be rated in the same way.<\/p>\n<p><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/glossary-bibliography\/\">Chapter 6 (dynamic seating glossary and bibliography)<\/a> brings together the glossary, the index of the nineteen variables and the annotated bibliography, specifying for each source its contribution and its scope within the framework.<\/p>\n<\/section>\n<section class=\"bp-faq\" id=\"faq\">\n<h2>Frequently Asked Questions<\/h2>\n<details>\n<summary>What does this evaluation actually measure?<\/summary>\n<div class=\"faq-content\"><p>The capabilities a seating architecture offers the body: pelvic mobility, stabilization, independence of support points, pressure variation and response to micromovements. Level 1 establishes them through multi-criteria analysis; Level 2 aims to measure them through 3D kinematics, pressure mapping, mechanical thresholds and electromyography.<\/p><\/div>\n<\/details>\n<details>\n<summary>What is the difference between Level 1 and Level 2 evaluation?<\/summary>\n<div class=\"faq-content\"><p>Level 1 is a multi-criteria analysis, based on technical specifications, user feedback and expert judgment, that compares architectures using a common grid. Level 2 will associate each variable with an instrumented measurement method: 3D kinematics, pressure mapping, mechanical thresholds, EMG or tissue measurements.<\/p><\/div>\n<\/details>\n<details>\n<summary>Does Level 2 call the scientific basis of the framework into question?<\/summary>\n<div class=\"faq-content\"><p>Level 2 may call into question the model\u2019s functions, variables, boundaries and anchors. The documented phenomena and the validity of the framework are two separate questions.<\/p><\/div>\n<\/details>\n<details>\n<summary>When will the instrumented measurements take place?<\/summary>\n<div class=\"faq-content\"><p>Measurements are planned starting in 2027. No completed study is reported here.<\/p><\/div>\n<\/details>\n<details>\n<summary>Does the SBNFA\u2122 benchmark demonstrate a clinical benefit?<\/summary>\n<div class=\"faq-content\"><p>No. It evaluates the mechanical capabilities offered by seating architectures, through multi-criteria analysis. Effects on pain, fatigue or health fall within separate usage and clinical studies, which this dossier does not report.<\/p><\/div>\n<\/details>\n<details>\n<summary>Can a third party apply or challenge the evaluation?<\/summary>\n<div class=\"faq-content\"><p>Yes, and the framework is designed for exactly that: its criteria are independent of the solutions evaluated, each variable has anchors and each score must be justified. One can challenge a score, refine a variable, expand the sources or apply the grid to another device.<\/p><\/div>\n<\/details>\n<\/section>\n<section class=\"bp-sources\" id=\"references\">\n<h2>References<\/h2><p>The contribution and scope of each source are detailed in <a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/glossary-bibliography\/#section-3\">Chapter 6 (annotated bibliography)<\/a>. A reference associated with a variable documents a phenomenon; it does not validate the variable.<\/p>\n<ol>\n<li id=\"ref-1\"><strong>Blue Portance, 2026 (a)<\/strong> \u2014 SBNFA\u2122 Framework for Evaluating Seating Devices \u2014 Part I: Scientific and Methodological Framework. Internal document, version of August 3, 2026.<\/li>\n<li id=\"ref-2\"><strong>Ellegast et al., 2012<\/strong> \u2014 <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/21714953\/\">Comparison of four specific dynamic office chairs with a conventional office chair: impact upon muscle activation, physical activity and posture<\/a>. Applied Ergonomics, 43(2), 296\u2013307.<\/li>\n<li id=\"ref-3\"><strong>Gregory, Dunk &amp; Callaghan, 2006<\/strong> \u2014 <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/16696264\/\">Stability ball versus office chair: comparison of muscle activation and lumbar spine posture during prolonged sitting<\/a>. Human Factors, 48(1), 142\u2013153.<\/li>\n<li id=\"ref-4\"><strong>Roman-Liu, Kami\u0144ska &amp; Tokarski, 2023<\/strong> \u2014 <a href=\"https:\/\/peerj.com\/articles\/16176\/\">Differences in lumbar spine intradiscal pressure between standing and sitting postures: a comprehensive literature review<\/a>. PeerJ, 11, e16176.<\/li>\n<li id=\"ref-5\"><strong>Stergiou &amp; Decker, 2011<\/strong> \u2014 <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/21802756\/\">Human movement variability, nonlinear dynamics, and pathology: is there a connection?<\/a>. Human Movement Science, 30(5), 869\u2013888.<\/li>\n<li id=\"ref-6\"><strong>Blue Portance, 2026 (c)<\/strong> \u2014 SBNFA\u2122 Framework \u2014 Part III: Monographs and Comparative Evaluation (V14). Internal document, August 25, 2026.<\/li>\n<\/ol>\n<\/section>\n<\/article>\n<nav aria-label=\"Dossier navigation\" class=\"bp-pagination\"><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/dynamic-chair-benchmark\/\">\u2190 Product Benchmark: A Dated Application of the Framework<\/a><a href=\"https:\/\/blueportance.com\/en\/knowledge-base\/expert-guides\/living-flows\/adaptability-potential-sitting\/glossary-bibliography\/\">Appendices, Glossary, and Bibliography \u2192<\/a><\/nav><footer><p>SBNFA\u2122 Dossier \u00b7 Version 1.1 \u00b7 October 5, 2026 \u00b7 \u00a9 Blue Portance.<\/p><\/footer>\n\n","protected":false},"excerpt":{"rendered":"<p>Pillar1 \u00b7 From Fixed Mechanism to Living System2 \u00b7 Four Foundational Principles3 \u00b7 Seven Functions, Nineteen Variables4 \u00b7 Product Benchmark: A Dated Application of the Framework5 \u00b7 From Expert Evaluation to Instrumented Measurement6 \u00b7 Appendices, Glossary, and Bibliography SBNFA\u2122 Dossier \u00b7 Version 1.1 of October 5, 2026Gil Ayache, PhD \u2014 Mines Paris \u2013 PSL \u00b7 [&#8230;]\n","protected":false},"author":6,"featured_media":0,"parent":8233,"menu_order":5,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_yoast_wpseo_title":"Chair Evaluation: From Multi-Criteria Analysis to Measurement | Blue Portance","_yoast_wpseo_metadesc":"What a chair evaluation measures: multi-criteria analysis, then 3D kinematics, pressure mapping and EMG in the SBNFA\u2122 framework.","footnotes":""},"pathologie_secondaire":[],"effet_positif":[],"class_list":["post-8244","page","type-page","status-publish","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v28.7 (Yoast SEO v28.7) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Chair Evaluation: From Multi-Criteria Analysis to Measurement | Blue Portance<\/title>\n<meta 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