The test protocols usually include a Sensory Organization Test (SOT), Limits of Stability Test (LOS), a Motor Control Test (MCT) and an Adaptation Test (ADT). The SOT test was developed by Nashner and is a computerized system that is made up of dual movable force plates and movable visual screen (EquiTest). During the test the patient is instructed to stand still and quietly with eyes open or closed depending on which of the six tests is being administered. The patient performs multiple trials per test; a description of these tests can be found in the table below. The SOT test is based on the fact that there are three sensory systems mainly involved in maintaining balance (vision, vestibular, and
proprioceptive). Minute spontaneous body sways are measured as well as reactions provoked by unexpected abrupt movements of the platform and the visual surroundings. Differences in these sways and reactions to system perturbations help to determine the patients ability to effectively use visual, vestibular, and proprioceptive input to maintain posture. Wrisley et al. (2007) found that there are learning effects associated with the SOT test and therefore it could be used clinically to assess, improve and track changes in balance. SOT results are subdivided in an Equilibrium Score, a Sensory Analysis, a Strategy Analysis and COG Alignment. The sensory analysis calculates 4 different scores: somatosensory (SOM), visual (VIS), vestibular (VEST) and visual preference (PREF) (otherwise known as "visual dependence", an excessive reliance on visual information even when it is inappropriate). The scores are respectively calculated as ratios of the 6 different scores of the equilibrium score: \text{Somatosensory (SOM)} = \frac{\text{condition 2}}{\text{condition 1}} \text{Visual (VIS)} = \frac{\text{condition 4}}{\text{condition 1}} \text{Vestibular (VEST)} = \frac{\text{condition 5}}{\text{condition 1}} \text{Visual Preference (PREF)} = \frac{\text{conditions 3 + 6}}{\text{conditions 2 + 5}} MCT results include instead the Weight Symmetry, both for forward and for backward translations, Latency Scores for forward and backward translations, and Amplitude Scaling, which refers to the capacity of the participant to generate a response force adequate to the entity of the perturbation. The limits of stability (LOS) is defined as the distance outside the base of support that can be traveled before a loss of balance occurs. The LOS test is frequently used to quantify this distance and has been suggested as a hybrid between static and dynamic balance assessment. During this test the patient stands on the platform as directed above in the SOT test. The patient watches their movements on a screen so they can see each of the eight LOS targets. The patient begins with their COP directly in the center of the targets (displayed as a figure as a computerized person). At the onset of the test, the patient attempts to lean in the direction of the indicated perimeter target, without lifting their feet, and hold there until the test is complete. According to necessity of the diagnostic workup, CDP can be combined with other techniques, such as
electronystagmography (ENG) and
electromyography. The main indications for CDP are
dizziness and
vertigo, and postural imbalances (
balance disorders). ==See also==