Learning effect of standing on foam during posturographic testing – preliminary findings

Balance protocols such as the modified Clinical Test of Sensory Integration on Balance (mCTSIB) or the Balance Error Scoring System (BESS) include testing a person while standing on a thick foam cushion. The role of the foam cushion is to perturb the somatosensory and proprioceptive information and to provide an unstable and unpredictable standing surface. This, combined with asking the subject to keep the eyes closed during the test, is to make the subject rely mostly on the vestibular system to maintain balance. However, this type of condition rarely occurs in real life. It is not well understood if learning and/or fatiguing might affect the results of these type of tests. This has important methodological consequences for balance protocols in terms of the number of repetitions and how these might affect the results of the balance tests. In this study, the balance of 25 healthy subjects who had never undergone this type of testing was evaluated. The subjects performed in rapid succession 4, 60s long posturographic tests while standing on a foam cushion. A computerized posturographic device was used to collect the data. Half of the participants performed the tests with eyes open and half with eyes closed. This allowed to discover the presence of a “learning effect” the first time subjects are tested on the foam cushion. Once the subjects had learned to stand on the foam cushion, the length of the tests and the number of repetitions did not show a statistically significant effect.