Library
Glossary
Definitions of the terms used throughout the atlas. Each term carries aliases used by the search and cross-links to related concepts.
- Adaptation TestADT
Tests the central nervous system's ability to suppress an inappropriate postural response across repeated trials of the same support-surface rotation (toes up or toes down). Sway energy normally decreases trial-on-trial.
See also: sway-energy, central-adaptation
- Amplitude scaling
The MCT measure of how well the magnitude of the postural response matches the size of the perturbation. Under-scaling is seen in peripheral neuropathy; over-scaling can be seen in anxious and PPPD patients.
- Ankle strategy
A postural correction generated primarily by torque at the ankle joints. Predominates for small perturbations on stable surfaces.
See also: hip-strategy, los
- Aphysiologic patternnon-organic pattern · functional pattern · Cevette pattern
A pattern in which performance on the easier SOT conditions (C1–C4) is paradoxically worse than on the harder C5/C6, often with high intertrial variability. Raises the question of a functional disorder or feigned disease; first formally described by Cevette et al. (1995).
- Central adaptation
The CNS's ability to suppress an inappropriate or unhelpful postural response by learning from previous experience with the same stimulus. Failure of central adaptation produces a non-adapting ADT.
See also: adt
- Centre of gravityCOG · center of gravity
The point representing the average position of body mass. In CDP, COG sway is inferred from the COP trajectory and the patient's height.
See also: cop
- Centre of pressureCOP · center of pressure
The point on the support surface where the resultant of the ground reaction force acts. Movement of COP under quiet stance is a primary CDP measurement.
See also: cog, force-plate
- Composite equilibrium scorecomposite score · SOT composite
Weighted average of the equilibrium scores across all SOT conditions; the single most reported summary metric. Age-stratified normative thresholds apply.
See also: equilibrium-score, sot
- Computerized Dynamic PosturographyCDP · posturography · dynamic posturography
A force-plate-based functional assessment of the balance system that uses sway-referencing of the support surface and visual surround to selectively challenge somatosensory, visual, and vestibular inputs. Comprises three test protocols: SOT, MCT, and ADT.
See also: sot, mct, adt, sway-referencing, force-plate
- Equilibrium scoreEQS · equilibrium scores
A nondimensional 0–100 score per SOT condition, computed from the patient's peak anterior-posterior sway relative to the theoretical 12.5° limit of stability. 100 = no sway; 0 = fall.
See also: sot, composite-score
- Force platedual force plate · platform
Instrumented platform with strain gauges or load cells that measures the vertical and shear forces applied by each foot, from which the centre of pressure (COP) is computed.
- Hip strategy
A postural correction generated by flexion or extension at the hips. Recruited for large or rapid perturbations and when ankle torque is insufficient or unavailable (e.g. on a narrow surface).
See also: ankle-strategy
- Limits of stabilityLOS
The maximum distance the centre of gravity can be displaced from vertical without losing balance — approximately 12.5° anterior-posteriorly in healthy adults.
See also: cog, ankle-strategy
- MCT latencypostural response latency
Time from the onset of platform translation to the onset of the patient's postural response, in milliseconds. Prolonged latencies suggest central pathway involvement.
See also: mct, amplitude-scaling
- Motor Control TestMCT
An automatic-postural-response test in which the force plate translates suddenly forward or backward at small, medium, and large amplitudes. Records latency, amplitude scaling, and weight symmetry of the patient's involuntary response.
See also: latency, amplitude-scaling, weight-symmetry
- Persistent postural-perceptual dizzinessPPPD
A clinically-defined chronic functional dizziness disorder (Bárány Society 2017). On CDP, often shows visual preference and exaggerated MCT amplitudes, though findings are supportive rather than diagnostic.
See also: sensory-ratios, aphysiologic-pattern
- Sensory analysis ratiosSOM ratio · VIS ratio · VEST ratio · PREF ratio · visual preference
Four ratios derived from SOT condition pairs that quantify the patient's use of each sensory input: somatosensory (C2/C1), visual (C4/C1), vestibular (C5/C1), and visual preference ((C3+C6)/(C2+C5)).
See also: sot, equilibrium-score
- Sensory Organisation TestSOT · Sensory Organization Test
The voluntary stance subtest of CDP. Six conditions systematically vary the availability and reliability of visual and somatosensory cues; equilibrium scores are derived from anterior-posterior body sway.
See also: sot-conditions, equilibrium-score, sensory-ratios
- SOT conditions
Six standardised stance conditions: (1) eyes open, fixed; (2) eyes closed, fixed; (3) eyes open, sway-referenced surround; (4) eyes open, sway-referenced platform; (5) eyes closed, sway-referenced platform; (6) eyes open, both sway-referenced.
See also: sot, sway-referencing
- Sway energy
The ADT outcome measure — the integrated movement of the centre of pressure during a single toes-up or toes-down rotation trial. Normally decreases across the five repeated trials.
See also: adt, central-adaptation
- Sway-referencing
A technique unique to CDP in which the support surface, the visual surround, or both rotate in real time to match the patient's body sway, effectively cancelling the sensory information that input would normally provide.
- Vestibular neuritisVN
An acute, presumed-viral or post-viral unilateral peripheral vestibulopathy producing severe vertigo and a characteristic SOT vestibular pattern, often with falls on C5/C6 in the acute phase.
See also: vestibular-pattern, sot
- Vestibular pattern
Selective abnormality on SOT conditions 5 and 6 with preserved performance on C1–C4. Seen in unilateral and bilateral peripheral vestibular loss, vestibular neuritis, and uncompensated lesions.
See also: sot-conditions, vestibular-neuritis
- Weight symmetry
On the MCT, the distribution of weight between the left and right legs at rest. Asymmetry suggests offloading from lower-limb pathology or chronic vestibular asymmetry.
See also: mct