Balance in Blind Subjects: Cane and Fingertip Touch Induce Similar Extent and Promptness of Stance Stabilization
Subjects with low vision often use a cane when standing and walking autonomously in everyday life. One aim of this study was to assess differences in the body stabilizing effect produced by the contact of the cane with the ground or by the fingertip touch of a firm surface. Another aim was to estima...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-09-01
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| Series: | Frontiers in Neuroscience |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fnins.2018.00639/full |
| _version_ | 1819063449269829632 |
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| author | Stefania Sozzi Francesco Decortes Monica Schmid Oscar Crisafulli Marco Schieppati |
| author_facet | Stefania Sozzi Francesco Decortes Monica Schmid Oscar Crisafulli Marco Schieppati |
| author_sort | Stefania Sozzi |
| collection | DOAJ |
| description | Subjects with low vision often use a cane when standing and walking autonomously in everyday life. One aim of this study was to assess differences in the body stabilizing effect produced by the contact of the cane with the ground or by the fingertip touch of a firm surface. Another aim was to estimate the promptness of balance stabilization (or destabilization) on adding (or withdrawing) the haptic input from cane or fingertip. Twelve blind subjects and two subjects with severe visual impairment participated in two experimental protocols while maintaining the tandem Romberg posture on a force platform. In one protocol, subjects lowered the cane to a second platform on the ground and lifted it in sequence at their own pace. In the other protocol, they touched an instrumented pad with the index finger and withdrew the finger from the pad in sequence. In both protocols, subjects were asked to exert a force not granting mechanical stabilization. Under steady-state condition, the finger touch or the contact of the cane with the ground significantly reduced (to ∼78% and ∼86%, respectively) the amplitude of medio-lateral oscillation of the centre of foot pressure (CoP). Oscillation then increased when haptic information was removed. The delay to the change in body oscillation after the haptic shift was longer for addition than withdrawal of the haptic information (∼1.4 s and ∼0.7 s, respectively; p < 0.001), but was not different between the two haptic conditions (finger and cane). Similar stabilizing effects of input from cane on the ground and from fingertip touch, and similar latencies to integrate haptic cue from both sources, suggest that the process of integration of the input for balance control is initiated by the haptic stimulus at the interface cane-hand. Use of a tool is as helpful as the fingertip input, and does not produce different stabilization. Further, the latencies to haptic cue integration (from fingertip or cane) are similar to those previously found in a group of sighted subjects, suggesting that integration delays for automatic balance stabilization are not modified by visual impairment. Haptic input from a tool is easily exploited by the neural circuits subserving automatic balance stabilization in blind people, and its use should be enforced by sensory-enhancing devices and appropriate training. |
| first_indexed | 2024-12-21T15:14:51Z |
| format | Article |
| id | doaj.art-e2f3223441844da5b3653ab702ecf3ba |
| institution | Directory Open Access Journal |
| issn | 1662-453X |
| language | English |
| last_indexed | 2024-12-21T15:14:51Z |
| publishDate | 2018-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Neuroscience |
| spelling | doaj.art-e2f3223441844da5b3653ab702ecf3ba2022-12-21T18:59:11ZengFrontiers Media S.A.Frontiers in Neuroscience1662-453X2018-09-011210.3389/fnins.2018.00639395374Balance in Blind Subjects: Cane and Fingertip Touch Induce Similar Extent and Promptness of Stance StabilizationStefania Sozzi0Francesco Decortes1Monica Schmid2Oscar Crisafulli3Marco Schieppati4Centro Studi Attività Motorie, Istituti Clinici Scientifici Maugeri, Pavia, ItalyCentro di Riabilitazione Visiva, Istituti Clinici Scientifici Maugeri, Pavia, ItalyCentro di Riabilitazione Visiva, Istituti Clinici Scientifici Maugeri, Pavia, ItalyDepartment of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal Child Health, University of Genoa, Genoa, ItalyDepartment of Exercise and Sport Science, LUNEX International University of Health, Exercise and Sports, Differdange, LuxembourgSubjects with low vision often use a cane when standing and walking autonomously in everyday life. One aim of this study was to assess differences in the body stabilizing effect produced by the contact of the cane with the ground or by the fingertip touch of a firm surface. Another aim was to estimate the promptness of balance stabilization (or destabilization) on adding (or withdrawing) the haptic input from cane or fingertip. Twelve blind subjects and two subjects with severe visual impairment participated in two experimental protocols while maintaining the tandem Romberg posture on a force platform. In one protocol, subjects lowered the cane to a second platform on the ground and lifted it in sequence at their own pace. In the other protocol, they touched an instrumented pad with the index finger and withdrew the finger from the pad in sequence. In both protocols, subjects were asked to exert a force not granting mechanical stabilization. Under steady-state condition, the finger touch or the contact of the cane with the ground significantly reduced (to ∼78% and ∼86%, respectively) the amplitude of medio-lateral oscillation of the centre of foot pressure (CoP). Oscillation then increased when haptic information was removed. The delay to the change in body oscillation after the haptic shift was longer for addition than withdrawal of the haptic information (∼1.4 s and ∼0.7 s, respectively; p < 0.001), but was not different between the two haptic conditions (finger and cane). Similar stabilizing effects of input from cane on the ground and from fingertip touch, and similar latencies to integrate haptic cue from both sources, suggest that the process of integration of the input for balance control is initiated by the haptic stimulus at the interface cane-hand. Use of a tool is as helpful as the fingertip input, and does not produce different stabilization. Further, the latencies to haptic cue integration (from fingertip or cane) are similar to those previously found in a group of sighted subjects, suggesting that integration delays for automatic balance stabilization are not modified by visual impairment. Haptic input from a tool is easily exploited by the neural circuits subserving automatic balance stabilization in blind people, and its use should be enforced by sensory-enhancing devices and appropriate training.https://www.frontiersin.org/article/10.3389/fnins.2018.00639/fullhapticscanefinger touchblindnessstance control |
| spellingShingle | Stefania Sozzi Francesco Decortes Monica Schmid Oscar Crisafulli Marco Schieppati Balance in Blind Subjects: Cane and Fingertip Touch Induce Similar Extent and Promptness of Stance Stabilization Frontiers in Neuroscience haptics cane finger touch blindness stance control |
| title | Balance in Blind Subjects: Cane and Fingertip Touch Induce Similar Extent and Promptness of Stance Stabilization |
| title_full | Balance in Blind Subjects: Cane and Fingertip Touch Induce Similar Extent and Promptness of Stance Stabilization |
| title_fullStr | Balance in Blind Subjects: Cane and Fingertip Touch Induce Similar Extent and Promptness of Stance Stabilization |
| title_full_unstemmed | Balance in Blind Subjects: Cane and Fingertip Touch Induce Similar Extent and Promptness of Stance Stabilization |
| title_short | Balance in Blind Subjects: Cane and Fingertip Touch Induce Similar Extent and Promptness of Stance Stabilization |
| title_sort | balance in blind subjects cane and fingertip touch induce similar extent and promptness of stance stabilization |
| topic | haptics cane finger touch blindness stance control |
| url | https://www.frontiersin.org/article/10.3389/fnins.2018.00639/full |
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