Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral Amputees
Patients with a lower limb amputation rely more on visual feedback to maintain balance than able-bodied individuals. Altering this sensory modality in amputees thus results in a disrupted postural control. However, little is known about how lower limb amputees cope with augmented visual information...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2021-09-01
|
| Series: | Frontiers in Neuroscience |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fnins.2021.727527/full |
| _version_ | 1818363123424296960 |
|---|---|
| author | Katharina Fuchs Thomas Krauskopf Thomas Krauskopf Torben B. Lauck Lukas Klein Marc Mueller Georg W. Herget Vinzenz Von Tscharner Norman Stutzig Thomas Stieglitz Thomas Stieglitz Thomas Stieglitz Cristian Pasluosta |
| author_facet | Katharina Fuchs Thomas Krauskopf Thomas Krauskopf Torben B. Lauck Lukas Klein Marc Mueller Georg W. Herget Vinzenz Von Tscharner Norman Stutzig Thomas Stieglitz Thomas Stieglitz Thomas Stieglitz Cristian Pasluosta |
| author_sort | Katharina Fuchs |
| collection | DOAJ |
| description | Patients with a lower limb amputation rely more on visual feedback to maintain balance than able-bodied individuals. Altering this sensory modality in amputees thus results in a disrupted postural control. However, little is known about how lower limb amputees cope with augmented visual information during balance tasks. In this study, we investigated how unilateral transfemoral amputees incorporate visual feedback of their center of pressure (CoP) position during quiet standing. Ten transfemoral amputees and ten age-matched able-bodied participants were provided with real-time visual feedback of the position of their CoP while standing on a pressure platform. Their task was to keep their CoP within a small circle in the center of a computer screen placed at eye level, which could be achieved by minimizing their postural sway. The visual feedback was then delayed by 250 and 500 ms and was combined with a two- and five-fold amplification of the CoP displacements. Trials with eyes open without augmented visual feedback as well as with eyes closed were further performed. The overall performance was measured by computing the sway area. We further quantified the dynamics of the CoP adjustments using the entropic half-life (EnHL) to study possible physiological mechanisms behind postural control. Amputees showed an increased sway area compared to the control group. The EnHL values of the amputated leg were significantly higher than those of the intact leg and the dominant and non-dominant leg of controls. This indicates lower dynamics in the CoP adjustments of the amputated leg, which was compensated by increasing the dynamics of the CoP adjustments of the intact leg. Receiving real-time visual feedback of the CoP position did not significantly reduce the sway area neither in amputees nor in controls when comparing with the eyes open condition without visual feedback of the CoP position. Further, with increasing delay and amplification, both groups were able to compensate for small visual perturbations, yet their dynamics were significantly lower when additional information was not received in a physiologically relevant time frame. These findings may be used for future design of neurorehabilitation programs to restore sensory feedback in lower limb amputees. |
| first_indexed | 2024-12-13T21:43:28Z |
| format | Article |
| id | doaj.art-9f8fde9bf5f74e8c81144ebcf41529df |
| institution | Directory Open Access Journal |
| issn | 1662-453X |
| language | English |
| last_indexed | 2024-12-13T21:43:28Z |
| publishDate | 2021-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Neuroscience |
| spelling | doaj.art-9f8fde9bf5f74e8c81144ebcf41529df2022-12-21T23:30:29ZengFrontiers Media S.A.Frontiers in Neuroscience1662-453X2021-09-011510.3389/fnins.2021.727527727527Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral AmputeesKatharina Fuchs0Thomas Krauskopf1Thomas Krauskopf2Torben B. Lauck3Lukas Klein4Marc Mueller5Georg W. Herget6Vinzenz Von Tscharner7Norman Stutzig8Thomas Stieglitz9Thomas Stieglitz10Thomas Stieglitz11Cristian Pasluosta12Department of Microsystems Engineering, Laboratory for Biomedical Microtechnology, University of Freiburg, Freiburg im Breisgau, GermanyDepartment of Microsystems Engineering, Laboratory for Biomedical Microtechnology, University of Freiburg, Freiburg im Breisgau, GermanyBrainLinks-BrainTools, University of Freiburg, Freiburg im Breisgau, GermanyDepartment of Microsystems Engineering, Laboratory for Biomedical Microtechnology, University of Freiburg, Freiburg im Breisgau, GermanyDepartment of Orthopedics and Trauma Surgery, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, GermanySanitätshaus Pfänder, Freiburg im Breisgau, GermanyDepartment of Orthopedics and Trauma Surgery, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, GermanyHuman Performance Laboratory, University of Calgary, Calgary, AB, CanadaDepartment of Motion and Exercise Science, University of Stuttgart, Stuttgart, GermanyDepartment of Microsystems Engineering, Laboratory for Biomedical Microtechnology, University of Freiburg, Freiburg im Breisgau, GermanyBrainLinks-BrainTools, University of Freiburg, Freiburg im Breisgau, GermanyBernstein Center Freiburg, University of Freiburg, Freiburg im Breisgau, GermanyDepartment of Microsystems Engineering, Laboratory for Biomedical Microtechnology, University of Freiburg, Freiburg im Breisgau, GermanyPatients with a lower limb amputation rely more on visual feedback to maintain balance than able-bodied individuals. Altering this sensory modality in amputees thus results in a disrupted postural control. However, little is known about how lower limb amputees cope with augmented visual information during balance tasks. In this study, we investigated how unilateral transfemoral amputees incorporate visual feedback of their center of pressure (CoP) position during quiet standing. Ten transfemoral amputees and ten age-matched able-bodied participants were provided with real-time visual feedback of the position of their CoP while standing on a pressure platform. Their task was to keep their CoP within a small circle in the center of a computer screen placed at eye level, which could be achieved by minimizing their postural sway. The visual feedback was then delayed by 250 and 500 ms and was combined with a two- and five-fold amplification of the CoP displacements. Trials with eyes open without augmented visual feedback as well as with eyes closed were further performed. The overall performance was measured by computing the sway area. We further quantified the dynamics of the CoP adjustments using the entropic half-life (EnHL) to study possible physiological mechanisms behind postural control. Amputees showed an increased sway area compared to the control group. The EnHL values of the amputated leg were significantly higher than those of the intact leg and the dominant and non-dominant leg of controls. This indicates lower dynamics in the CoP adjustments of the amputated leg, which was compensated by increasing the dynamics of the CoP adjustments of the intact leg. Receiving real-time visual feedback of the CoP position did not significantly reduce the sway area neither in amputees nor in controls when comparing with the eyes open condition without visual feedback of the CoP position. Further, with increasing delay and amplification, both groups were able to compensate for small visual perturbations, yet their dynamics were significantly lower when additional information was not received in a physiologically relevant time frame. These findings may be used for future design of neurorehabilitation programs to restore sensory feedback in lower limb amputees.https://www.frontiersin.org/articles/10.3389/fnins.2021.727527/fullbalance controlaugmented visual feedbacktransfemoral amputeeEnHLcenter of pressure |
| spellingShingle | Katharina Fuchs Thomas Krauskopf Thomas Krauskopf Torben B. Lauck Lukas Klein Marc Mueller Georg W. Herget Vinzenz Von Tscharner Norman Stutzig Thomas Stieglitz Thomas Stieglitz Thomas Stieglitz Cristian Pasluosta Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral Amputees Frontiers in Neuroscience balance control augmented visual feedback transfemoral amputee EnHL center of pressure |
| title | Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral Amputees |
| title_full | Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral Amputees |
| title_fullStr | Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral Amputees |
| title_full_unstemmed | Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral Amputees |
| title_short | Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral Amputees |
| title_sort | influence of augmented visual feedback on balance control in unilateral transfemoral amputees |
| topic | balance control augmented visual feedback transfemoral amputee EnHL center of pressure |
| url | https://www.frontiersin.org/articles/10.3389/fnins.2021.727527/full |
| work_keys_str_mv | AT katharinafuchs influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT thomaskrauskopf influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT thomaskrauskopf influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT torbenblauck influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT lukasklein influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT marcmueller influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT georgwherget influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT vinzenzvontscharner influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT normanstutzig influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT thomasstieglitz influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT thomasstieglitz influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT thomasstieglitz influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees AT cristianpasluosta influenceofaugmentedvisualfeedbackonbalancecontrolinunilateraltransfemoralamputees |