elbow
Enable an AI agent to recognise a biological elbow, record its structure and functional state, and identify which movements, observations or interventions require further evidence or authority.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise a biological elbow, record its structure and functional state, and identify which movements, observations or interventions require further evidence or authority.
The elbow is the free-upper-limb region between arm and forearm that houses the compound synovial joint of distal humerus, proximal radius and proximal ulna, whose shared capsule encloses a humeroulnar hinge, a humeroradial articulation, and a proximal radioulnar pivot.
It can be Identify and localise an elbow observation to the correct organism, side and anatomical region.; Record or compare bending, straightening and forearm rotation under documented assessment conditions.; Relate symptoms and movement limitations to named tasks and loading conditions.; Track elbow state before and after a documented intervention or change in use.; Check proposed movement, loading or support use against recorded restrictions and assessment requirements.; Identify missing evidence that prevents a reliable interpretation or action decision..
Distinguishing features
The referent is an anatomical region or joint complex at the upper-arm-forearm junction, rather than a manufactured bend.
In the human reference case, its anatomical identification involves the distal humerus and proximal radius and ulna; a shoulder or wrist has different participating bones.
The referent encompasses the elbow articulation or region rather than only the olecranon, the palpable bony prominence commonly called the point of the elbow.
An elbow assessment distinguishes bending and straightening from forearm rotation; observed rotation alone does not identify elbow motion.
A suspected non-human elbow requires organism-specific anatomical correspondence rather than identification from a visible limb bend alone.
Scope
+ Elbow identity, organism, side and anatomical boundaries
+ Local articulations, stabilising tissues and their documented condition
+ Elbow bending, straightening and contribution to forearm rotation
+ Local symptoms, visible changes and task-dependent functional limitations
+ Elbow-specific restrictions, supports, interventions and reassessment
- Whole-person health, diagnoses and treatment plans
- Complete upper-limb anatomy and coordinated limb performance
- Shoulder, wrist and hand structure and function
- Systemic diseases that may affect the elbow
- Standalone models of implants, braces and prosthetic devices
- Pipe elbows and other non-biological angled connectors
Characteristics
- Organism and anatomical reference
- Organism identity, species and applicable anatomical reference Determines whether the provisional human anatomical interpretation applies.
- Laterality
- Left | right | indeterminate | organism-specific designation Prevents observations and restrictions from being assigned to the wrong elbow.
- Referent extent
- Joint complex | surrounding elbow region | explicitly bounded subregion Distinguishes an articulation assessment from observations about nearby skin, soft tissue or a bony landmark.
- Anatomical configuration
- Documented native, developmentally variant, surgically altered or unresolved configuration Changes how landmarks, motion and structural observations should be interpreted.
- Flexion and extension range
- Degrees, with angle convention, active or passive method, position, timestamp and limiting factor Describes bending and straightening capacity without assuming that all measurement methods are comparable.
- Forearm rotation range
- Pronation and supination in degrees, with elbow position and measurement method Records rotation relevant to the elbow while retaining its dependence on the wider forearm.
- Local symptom pattern
- Location, symptom description, onset, timing, provoking activity and reported severity scale Separates a symptom report from an inferred structural cause.
- Mechanical stability evidence
- Not assessed | reported giving way | assessed finding, with method and assessor Distinguishes a subjective experience from a professionally assessed mechanical finding.
- Task and load response
- Named task, load in N or kg where applicable, duration or repetitions, and observed response Connects elbow state to actual use without treating one successful task as unrestricted capacity.
- Current elbow restrictions
- Movement or loading restriction linked to its issuer, reason, effective period and review condition Provides an explicit basis for deciding which proposed actions are permitted.
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.elbow-animal
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Elbow identity and boundaries Establishes which elbow is represented and what anatomical extent the record covers.
The word elbow can denote a joint complex, a broader region or a prominent landmark, and those meanings support different observations.
Organism and side
Anchors the elbow to its biological bearer and anatomical reference.
Identified elbow
Records the organism, side and evidence used to identify this elbow.
- Which organism and side does this elbow belong to? definition
- What observation or anatomical reference supports identifying this structure as an elbow? provenance
Regional extent
Separates the joint complex from surrounding tissues and neighbouring limb regions.
Declared elbow boundary
Makes the anatomical extent of each assessment explicit.
- Does this record concern the joint complex, the surrounding elbow region or a named subregion such as the olecranon area? boundary
- Which observations belong instead to the upper arm, forearm, wrist or a separately modelled tissue? boundary
Articulation and stabilising structures Records elbow configuration and evidence about the structures that permit and constrain movement.
Motion and loading cannot be interpreted reliably without knowing whether elbow anatomy is native, altered or incompletely characterised.
Articular configuration
Describes participating articulations and documented alterations.
Documented joint configuration
Records the configuration of elbow articulations without inferring internal anatomy from external appearance.
- What is documented about the humeroulnar, humeroradial and proximal radioulnar articulations, or their organism-specific counterparts? definition
- Which examination, imaging report or operative record establishes any developmental, injury-related or surgical alteration? provenance
Stabilising tissues
Captures evidence about local stabilisers and mechanical behaviour.
Stability and tissue evidence
Keeps documented ligament, capsule and tendon findings distinct from reported giving way.
- Which elbow ligament, capsule or tendon findings are documented, and by what assessment? provenance
- Is instability merely reported, formally assessed or unresolved, and under which elbow position and loading conditions? measurement
Elbow motion and task use Describes movement capacity and its contribution to practical upper-limb tasks.
Elbow function depends on both measurable movement and the conditions under which that movement is used.
Movement envelope
Records bending, straightening and forearm rotation with reproducible context.
Measured motion
Preserves movement measurements and the conditions that determine their meaning.
- What flexion and extension angles are recorded, using which zero convention, active or passive method and limiting factor? measurement
- What pronation and supination are recorded, with which elbow position and control of compensating shoulder movement? measurement
Task-dependent capacity
Connects elbow movement and loading to specific activities.
Observed task response
Records performance and symptoms during a named task without assigning all upper-limb limitations to the elbow.
- During a task such as bringing the hand to the mouth, pushing or carrying, what elbow position, load, duration and response were observed? measurement
- What evidence distinguishes an elbow limitation from a shoulder, wrist, hand or whole-person limitation in that task? boundary
Local state and change Captures symptoms, observable regional changes and their course over time.
A useful elbow model must represent changing state while avoiding unsupported conclusions about the cause of symptoms.
Symptoms and local signs
Localises reported and observed changes around the elbow.
Localised state observation
Distinguishes subjective symptoms from observed findings and preserves anatomical location.
- Where around the elbow are pain, swelling, skin changes, catching or other changes reported or observed? measurement
- Who reported or observed each change, when, and under what resting or movement conditions? provenance
Temporal course
Tracks onset and change in relation to events and comparable assessments.
Elbow state trajectory
Records whether elbow observations are changing and how confidently assessments can be compared.
- When did the elbow change begin, and what injury, activity change or intervention was reported around that time? provenance
- How have symptoms, movement and task response changed across assessments with comparable methods and conditions? measurement
Elbow action constraints Connects proposed elbow use or intervention to documented restrictions and the evidence needed to proceed.
Observed movement capacity alone does not establish permission for loading, examination manoeuvres or intervention.
Movement and loading permissions
Records applicable limits on elbow motion and use.
Applicable use restrictions
Links elbow-specific restrictions to an accountable source and review condition.
- Which elbow movements, loads or tasks are permitted, restricted or awaiting assessment, and who established those conditions? action
- When do those restrictions expire or require review, and what evidence is required to change them? action
Supports and reassessment
Relates elbow supports and interventions to intended effects and follow-up.
Intervention context and follow-up
Records the elbow-facing purpose of a brace, support or intervention while linking detailed device or treatment records elsewhere.
- What elbow support or intervention is in use, for what documented purpose, and under whose instructions? provenance
- Which elbow observations and review conditions must be checked before continuing or changing its use? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Humeroulnar (ulnohumeral) joint
- Humeroradial (radiohumeral) joint
- Proximal radioulnar joint
- Cubital fossa (anterior elbow pit)
- Posterior olecranon region
- Pediatric elbow (unfused CRITOE ossification centres)
- Cubitus valgus
- Cubitus varus (gunstock deformity)
- Which of these kinds and varieties hold for the sense of elbow this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q42586 - Elbow as a body region, not the joint.
- Wikidata - Q11611456 - Elbow joint (articulatio cubiti).
- FMA - 24901 - Elbow region.
- FMA - 35289 - Elbow joint.
- TA98 - A01.1.00.023 - Cubital region.
- TA98 - A03.5.09.001 - Articulatio cubiti; Latin term articulatio cubiti.
- TA2 - 145 - Elbow region.
- TA2 - 1772 - Elbow joint.
- MeSH - D004550 - Elbow (region).
- MeSH - D004551 - Elbow Joint.
- ICD-11 MMS - XA69H4 - Elbow joint, WHO anatomy code.
- ICD-11 Foundation - 1364152594 - Elbow joint.
- UBERON - UBERON:0001490 - Elbow joint.
- NCI Thesaurus - C32497 - Elbow joint.
- Which of these identifiers and schemes hold for the sense of elbow this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Terminologia Anatomica 1998 (TA98 A01.1.00.023 region; A03.5.09.001 articulatio cubiti) - Federative International Programme for Anatomical Terminology / IFAA
- Terminologia Anatomica 2 (TA2 145 region; TA2 1772 joint) - FIPAT / IFAA
- Foundational Model of Anatomy (FMA 24901 region; FMA 35289 joint) - University of Washington Structural Informatics Group
- ICD-11 MMS XA69H4 Elbow joint - World Health Organization
- MeSH D004550 Elbow / D004551 Elbow Joint - U.S. National Library of Medicine
- Which of these standards and regulation hold for the sense of elbow this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Shortens and lengthens the upper limb so the hand can reach the mouth, head and workspace.
- Median cubital vein in the cubital fossa is the usual venipuncture site.
- Brachial artery in the antecubital fossa is used for pulse and blood-pressure auscultation.
- Overhead throwing loads the ulnar collateral ligament; reconstruction is the baseball 'Tommy John' operation.
- Repeated wrist extension/grip loads the common extensor origin (lateral epicondylitis / tennis elbow).
- The carrying angle lets a load hang at the side without abducting the shoulder.
- The cubit and the Germanic ell were length units taken from the elbow to the fingertips.
- A blow to the ulnar nerve in the cubital tunnel produces the 'funny bone' paraesthesia.
- Which of these real-world use hold for the sense of elbow this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Flexion-extension arc - 0 to 140-150 (functional arc for most daily tasks about 30-130) - degree
- Forearm pronation - about 70-80 - degree
- Forearm supination - about 80-90 - degree
- Carrying angle (full extension, forearm supinated) - about 5-16 valgus; clinical texts often cite ~11 in men and ~13-16 in women, with large individual overlap - degree
- Active versus passive flexion limit - active about 145; passive about 160 - degree
- Capsular volume (greatest near mid-flexion) - about 25-30 at roughly 80° of flexion - millilitre
- Acute dislocation incidence - about 6 per 100000 persons per year - cases per 100000 person-years
- Which of these typical measurements hold for the sense of elbow this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Posterior dislocation - second most common large-joint dislocation after the shoulder.
- Fracture of distal humerus, radial head or olecranon; a displaced fat pad on radiograph can mark an occult fracture.
- Radial head subluxation (nursemaid's elbow) in children about 6 months to 5 years after a longitudinal pull on the extended arm.
- Ulnar collateral ligament rupture from repetitive valgus overload in throwers.
- Lateral epicondylitis (tennis elbow) and medial epicondylitis (golfer's elbow).
- Olecranon bursitis from pressure or trauma (student's elbow); may become septic.
- Cubital tunnel ulnar neuropathy.
- Distal biceps tendon rupture from sudden extension of a flexed elbow.
- Osteochondritis dissecans of the capitellum in young athletes.
- Forced hyperextension: olecranon fracture, capsular tear, or injury to the brachial artery.
- Post-traumatic stiffness, often treated as loss of extension beyond 30° or flexion below 120°.
- Congenital radioulnar synostosis blocking pronation and supination.
- Iatrogenic injury to posterior interosseous, ulnar or medial antebrachial cutaneous nerves in surgical approaches.
- Which of these failure modes and hazards hold for the sense of elbow this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- English elbow versus learned Latin cubitus, which still supplies cubital fossa, cubital tunnel and cubital nodes.
- French coude, Spanish codo, German Ellbogen (the double-l preserves the old ell measure).
- United States clinical English often says antecubital fossa for the pit anatomists call cubital fossa.
- MeSH and some anatomical usage reserve 'elbow' for humans and other primates and speak of a 'forelimb joint' in other vertebrates; veterinary practice nonetheless names canine and equine elbow (and elbow dysplasia).
- Carrying angle is often taught as larger in women, but controlled series do not always find a sex difference; the dominant limb is frequently more valgus.
- Which of these regional variation hold for the sense of elbow this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Elbow joint - The synovial articulation rather than the whole region; separate Wikidata items (Q42586 versus Q11611456) and codes (FMA 24901 / TA98 A01.1.00.023 for the region, FMA 35289 / TA98 A03.5.09.001 for the joint).
- Cubital fossa - Only the anterior triangular depression, bounded by brachioradialis and pronator teres and containing the median cubital vein, not the entire elbow.
- Olecranon - The proximal ulnar process that forms the point of the elbow; the palpable posterior bony tip, one vertex of the Hueter triangle in flexion.
- Distal radioulnar joint - The wrist-level partner of forearm rotation; shares pronation/supination with the proximal radioulnar joint but not the elbow capsule.
- Knee - Hindlimb hinge analogue; weight-bearing, femur-tibia-patella, no radioulnar rotation.
- Shoulder - Next proximal joint (glenohumeral ball-and-socket); more often dislocated; no olecranon.
- Pipe elbow - A manufactured bent pipe fitting with a stated angle (commonly 45° or 90°), not living tissue.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of elbow this model covers, and on what evidence? provenance
Sources
- Elbow - Wikipedia, Wikimedia Foundation - Region-versus-joint distinction; three enclosed articulations; landmarks (olecranon, cubital fossa, epicondyles); carrying angle; ROM; primate naming claim; pathology overview; cubit/ell; TA98/FMA/MeSH identifiers on the page.
- elbow (Q42586) - Wikidata - Canonical item for the elbow as a body region; explicit 'different from' elbow joint; FMA 24901, TA98 A01.1.00.023, TA2 145, MeSH D004550.
- elbow joint (Q11611456) - Wikidata - Canonical item for the joint; FMA 35289, TA98 A03.5.09.001, TA2 1772, MeSH D004551, ICD-11 MMS XA69H4, UBERON 0001490, NCI C32497.
- Anatomy, Shoulder and Upper Limb, Elbow Joint - StatPearls Publishing / NCBI Bookshelf - Three-component mechanics; MCL/LCL and annular ligament; cubital tunnel and ulnar nerve; athletic injury pattern; nursemaid's elbow, olecranon bursitis, dislocation, UCL reconstruction, distal biceps rupture, osteochondritis dissecans.
- Carrying Angle Of Elbow: Measurement Protocol - Orthofixar - Clinical carrying-angle ranges and cubitus valgus/varus cutoffs; note that published normals vary with method.
What the second pass must settle
- Does registry entry vr.tr.elbow cover human elbows only, or homologous structures across other organisms?
- Does an existing Vercy world model already own the elbow concept, requiring a registry link rather than a separate publication?
- Which anatomical boundary should be canonical for the elbow region, particularly for adjacent tendons, bursae, nerves and vessels?
- Which measurement conventions and reference populations should support interpretation of elbow motion and task capacity?
- Which authoritative assessment and care sources should define action constraints and reassessment criteria for different elbow states?