scholarly journals Influence of Augmented Visual Feedback on Balance Control in Unilateral Transfemoral Amputees

2021 ◽  
Vol 15 ◽  
Author(s):  
Katharina Fuchs ◽  
Thomas Krauskopf ◽  
Torben B. Lauck ◽  
Lukas Klein ◽  
Marc Mueller ◽  
...  
Keyword(s):  
Postural Control ◽  
Real Time ◽  
Visual Feedback ◽  
Lower Limb ◽  
Center Of Pressure ◽  
Sensory Modality ◽  
Control Group ◽  
Eyes Open ◽  
Transfemoral Amputees ◽  
Lower Limb 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 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.

scholarly journals Maximal stability limits in adolescents with Tourette syndrome

2021 ◽  
Vol 4 (1) ◽  
pp. 013-022
Author(s):  
Blanchet Mariève ◽  
Prince François ◽  
Lemay Martin ◽  
Chouinard Sylvain ◽  
Messier Julie
Keyword(s):  
Postural Control ◽  
Tourette Syndrome ◽  
Center Of Pressure ◽  
Phase 1 ◽  
Sensory Information ◽  
Control Group ◽  
Eyes Closed ◽  
Highly Sensitive ◽  
Eyes Open ◽  
Stability Limits

We explored if adolescents with Gilles de la Tourette syndrome (GTS) had functional postural control impairments and how these deficits are linked to a disturbance in the processing and integration of sensory information. We evaluated the displacements of the center of pressure (COP) during maximal leaning in four directions (forward, backward, rightward, leftward) and under three sensory conditions (eyes open, eyes closed, eyes closed standing on foam). GTS adolescents showed deficits in postural stability and in lateral postural adjustments but they had similar maximal COP excursion than the control group. The postural performance of the GTS group was poorer in the eyes open condition (time to phase 1 onset, max-mean COP). Moreover, they displayed a poorer ability to maintain the maximum leaning position under the eyes open condition during mediolateral leaning tasks. By contrast, during forward leaning, they showed larger min-max ranges than control subjects while standing on the foam with the eyes closed. Together, these findings support the idea that GTS produces subclinical postural control deficits. Importantly, our results suggest that postural control disorders in GTS are highly sensitive to voluntary postural leaning tasks which have high demand for multimodal sensory integration.

scholarly journals Application of Real-Time Visual Feedback System in Balance Training of the Center of Pressure with Smart Wearable Devices

2020 ◽  
Author(s):  
I-Lin Wang ◽  
Li-I Wang ◽  
Yang Liu ◽  
Shi-Jie Xue ◽  
Rui Hu ◽  
...  
Keyword(s):  
Real Time ◽  
Visual Feedback ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Balance Training ◽  
Training Group ◽  
Wearable Devices ◽  
Control Group ◽  
Feedback Training ◽  
Smart Wearable

Abstract Background: Visual feedback from the center of pressure (COP) on the benefits of standing quietly remains controversial. The study was to investigate the adaptive effect of COP real-time visual feedback training provided by smart wearable devices on standing in silence. Methods: Thirty healthy female college students were randomly divided into three groups (visual feedback balance training group (VFT), non-visual feedback balance training group (NVFT) and control group (CG)) .Two force plates were used to calculate the coordinates of COP anteroposterior (COPAP) and COP mediolateral (COPML).The motion analysis system is used to calculate the coordinates of the center of mass in two directions. Enhanced visual feedback on the screen in the form of fluctuating in different directions, VFT received real-time visual feedback from Podoon APP for training, the NVFT only performs open eye balance without receiving real-time visual feedback. The CG group did not receive any visual feedback. The training lasted 4 weeks, the training lasts 30 minutes at an interval of 1 days. Results: After four weeks of balance training, the results showed that visual feedback training can improve the stability of human posture control by one leg stance and tandem stance static balance training on VFT intelligent App. The parameters of COPML/AP max displacement, COPML/AP velocity and COP radius and COP area in the VFT were significantly increased (p＜0.05).Conclusion: The conclusion shows that COP real-time visual feedback training provided by smart wearable devices can reduce postural sway better and improve body balance ability than general training when standing quietly.

scholarly journals Effectiveness of Virtual Reality and Visual Feedback on Balance and Leg Function in Children with Cerebral Palsy

2019 ◽  
Vol 1 (18) ◽  
Author(s):  
Arūnė Dūdaitė ◽  
Vilma Juodžbalienė
Keyword(s):  
Virtual Reality ◽  
Cerebral Palsy ◽  
Postural Control ◽  
Range Of Motion ◽  
Visual Feedback ◽  
Lower Limb ◽  
Dynamic Balance ◽  
Control Group ◽  
Children With Cerebral Palsy ◽  
Stretching Exercises

Research background. Virtual reality and visual feedback improve motor performance, motor function and balance, so we want to fnd if it affects the function of legs and balance of children with spastic hemiplegia. Research aim was to establish if the use of virtual reality and visual feedback with traditional physiotherapy improve the function of legs and balance of children with cerebral palsy. Methods. Nine children with cerebral palsy participated in the research. Participants were randomly divided into two groups – virtual reality group (n = 6) and control (n = 3). Virtual reality group practised exergaming and stretching exercises for 10 weeks, twice a week. Control group practiced conventional physiotherapy and stretching exercises for 6 weeks, twice a week. We measured the range of motion of the lower limb, spasticity of the lower limb using Modifed Ashworth’o Scale, static, dynamic balance, trunk coordination using Trunk Impairment Scale at the start and the end of the research, and balance using Pediatric Balance Scale. Results. Virtual reality and visual feedback reduced the spasticity of the lower limb, improved balance and postural control for children with cerebral palsy, but it did not improve the range of motion of the lower limb of children with cerebral palsy. Conclusions. Virtual reality and visual feedback did not improve the range of motion of the lower limb of children with cerebral palsy. Virtual reality and visual feedback reduced spasticity of the lower limb, improved balance and postural control for children with cerebral palsy.Keywords. Cerebral palsy, virtual reality, visual feedback, postural control, muscle architecture.

Stroboscopic Vision to Induce Sensory Reweighting During Postural Control

2017 ◽  
Vol 26 (5) ◽  
Author(s):  
Kyung-Min Kim ◽  
Joo-Sung Kim ◽  
Dustin R. Grooms
Keyword(s):  
Postural Control ◽  
Visual Feedback ◽  
Repeated Measures ◽  
Center Of Pressure ◽  
Somatosensory System ◽  
Lower Extremity Injury ◽  
Somatosensory Processing ◽  
Sensory Reweighting ◽  
Eyes Open ◽  
Almost All

Context: Patients with somatosensory deficits have been found to rely more on visual feedback for postural control. However, current balance tests may be limited in identifying increased visual dependence (sensory reweighting to the visual system), as options are typically limited to eyes open or closed conditions with no progressions between. Objective: To assess the capability of stroboscopic glasses to induce sensory reweighting of visual input during single-leg balance. Design:Descriptive Setting: Laboratory Participants: 18 healthy subjects without vision or balance disorders or lower extremity injury history (9 females; age = 22.1 ± 2.1 y; height = 169.8 ± 8.5 cm; mass = 66.5 ± 10.6 kg) participated. Interventions: Subjects performed 3 trials of unipedal stance for 10 s with eyes open (EO) and closed (EC), and with stroboscopic vision (SV) that was completed with specialized eyewear that intermittently cycled between opaque and transparent for 100 ms at a time. Balance tasks were performed on firm and foam surfaces, with the order randomized. Main Outcome Measures: Ten center-of-pressure parameters were computed. Results: Separate ANOVAs with repeated measures found significant differences between the 3 visual conditions on both firm (P-values =< .001) and foam (P-values =< .001 to .005) surfaces for all measures. For trials on firm surface, almost all measures showed that balance with SV was significantly impaired relative to EO, but less impaired than EC. On the foam surface, almost all postural stability measures demonstrated significant impairments with SV compared with EO, but the impairment with SV was similar to EC. Conclusions:SV impairment of single-leg balance was large on the firm surface, but not to the same degree as EC. However, the foam surface disruption to somatosensory processing and sensory reweighting to vision lead to greater disruptive effects of SV to the same level as EC. This indicates that when the somatosensory system is perturbed even a moderate decrease in visual feedback (SV) may induce an EC level impairment to postural control during single-leg stance.

scholarly journals Improving Postural Stability among Amputees by Tactile Sensory Substitution

2021 ◽  
Author(s):  
Lijun Chen ◽  
Yanggang Feng ◽  
Baojun Chen ◽  
Qining Wang ◽  
Kunlin Wei
Keyword(s):  
Postural Control ◽  
Real Time ◽  
Lower Limb ◽  
Postural Stability ◽  
Interaction Force ◽  
Sensory Substitution ◽  
Foot Pressure ◽  
Vibration Intensity ◽  
Lower Limb Amputees ◽  
Visual Disturbances

Abstract BackgroundFor lower-limb amputees, wearing a prosthetic limb helps restore their motor abilities for daily activities. However, the prosthesis's potential benefits are hindered by limited somatosensory feedback from the affected limb and its prosthesis. Previous studies have examined various sensory substitution systems to alleviate this problem; the prominent approach is to convert foot-ground interaction to tactile stimulations. However, positive outcomes for improving amputees' postural stability are still rare. We hypothesize that the intuitive design of tactile signals based on psychophysics shall enhance the feasibility and utility of real-time sensory substitution for lower-limb amputees. MethodsWe designed a wearable device consisting of four pressure sensors and two vibrators and tested it among the unilateral transtibial amputees (n=7) and the able-bodied (n=8). The real-time measurements of foot pressure were fused into a single representation of foot-ground interaction force, which was encoded by varying vibration intensity of the two vibrators attached to the participants’ forearm. The layout of vibrators was spatially congruent with the foot force sensors' placement; the vibration intensity followed a logarithmic function of the force representation, in keeping with principles of tactile psychophysics. The participants were tested with a classical postural stability task in which visual disturbances perturbed their quiet standing. ResultsWith a brief familiarization of the system, the participants exhibited better posture stability against visual disturbances when switching on sensory substitution than without. The body sway was substantially reduced, as shown in head movements and excursions of the center of pressure. The improvement was present for both amputees and able-bodied controls and was particularly pronounced in more challenging conditions with larger visual disturbances. ConclusionsSubstituting otherwise-missing foot pressure feedback with vibrotactile signals can improve postural stability for lower-limb amputees. The intuitive design of the mapping between the foot-ground interaction force and the tactile signals is essential for the user to utilize the surrogated tactile signals for postural control, especially for situations that their postural control is challenged.

Nociceptive capacity of plantar irritating stimulus reduction influences postural control in children, teenagers, and adults.

2015 ◽  
Vol 13 ◽  
pp. 298 ◽  
Author(s):  
Janin Marc ◽  
Lisandro Antonio Ceci ◽  
Rodolfo Borges Parreira
Keyword(s):  
Postural Control ◽  
Postural Balance ◽  
Center Of Pressure ◽  
Sensory Information ◽  
Control Group ◽  
Age Group ◽  
Sensory Organization ◽  
Pressure Area ◽  
Adolescents And Adults ◽  
Eyes Open

Introduction: Sensory information from vestibular, visual, proprioception, and feet contribute on postural control. Plantar afferent contribution comes from the tactile and nociceptive cues of the plantar sole. Nociceptive capacity of plantar irritating stimulus (NCPIS) is one of the foot problems that induce nociception. Objective: Was to determine the postural impact of sensory input flow modifications induced by foam in people with and without nociceptive plantar irritating stimuli in different ages (children, adolescents, and adults). Method: 120 participants with (NP) and X without (Ct) NCPIS in different age group were evaluated (20 subjects in each age group and conditions). Postural balance assessment was performed during two-legged stance test using a force platform. Postural recoding was performed with eyes open in two conditions: on a hard surface and on a foam surface. The postural balance parameter analyzed was center of pressure area and variance of speed. Results: Area and variance of speed in control group increased, whereas decreased in NP subjects. No differences were observed for mean speed. In the Ct group, nociceptor and mechanoreceptor afferent sensations on foam induced postural variation with more oscillations (area and speed). Conclusion: NCPIS influenced postural control, and this foam neutralization of afferent nociception induced a new sensory organization. Foam surface imitated afferent plantar sensory information, induced postural variation as measured by CoP parameters with increasing postural control in subjects without NCIPS and decreasing postural control in subjects with NCPIS.

scholarly journals Application of Real-Time Visual Feedback System in Balance Training of the Center of Pressure with Smart Wearable Devices

2021 ◽  
Vol 18 (18) ◽  
pp. 9637
Author(s):  
I-Lin Wang ◽  
Li-I Wang ◽  
Yang Liu ◽  
Yu Su ◽  
Shun Yao ◽  
...  
Keyword(s):  
Real Time ◽  
Visual Feedback ◽  
Center Of Pressure ◽  
Balance Training ◽  
Training Group ◽  
Wearable Devices ◽  
Control Group ◽  
Feedback Training ◽  
The One ◽  
Smart Wearable

Balance control with an upright posture is affected by many factors. This study was undertaken to investigate the effects of real-time visual feedback training, provided by smart wearable devices for COP changes for healthy females, on static stance. Thirty healthy female college students were randomly divided into three groups (visual feedback balance training group, non-visual feedback balance training group, and control group). Enhanced visual feedback on the screen appeared in different directions, in the form of fluctuations; the visual feedback balance training group received real-time visual feedback from the Podoon APP for training, while the non-visual feedback balance training group only performed an open-eye balance, without receiving real-time visual feedback. The control group did not do any balance training. The balance training lasted 4 weeks, three times a week for 30 min each time with 1–2 day intervals. After four weeks of balance training, the results showed that the stability of human posture control improved for the one leg static stance for the visual feedback balance training group with smart wearable devices. The parameters of COP max displacement, COP velocity, COP radius, and COP area in the visual feedback balance training group were significantly decreased in the one leg stance (p < 0.05). The results showed that the COP real-time visual feedback training provided by smart wearable devices can better reduce postural sway and improve body balance ability than general training, when standing quietly.

scholarly journals Qigong for Muscle Strength and Static Postural Control in Middle-Aged and Older Postmenopausal Women: A Randomized Controlled Trial

2021 ◽  
Vol 8 ◽  
Author(s):  
María del Carmen Carcelén-Fraile ◽  
Agustín Aibar-Almazán ◽  
Antonio Martínez-Amat ◽  
Vânia Brandão-Loureiro ◽  
José Daniel Jiménez-García ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Postural Control ◽  
Postmenopausal Women ◽  
Center Of Pressure ◽  
Controlled Trial ◽  
Exercise Program ◽  
Control Group ◽  
Middle Aged ◽  
Eyes Open ◽  
Experimental Group

In the present study, we aimed to determine the effects of a Qigong exercise program on the muscle strength and postural control in middle-aged and older postmenopausal women. This is a randomized clinical trial (https://clinicaltrials.gov/ct2/show/NCT03989453) conducted on 125 women who were initially assigned to either an experimental group (n = 63) that performed a Qigong exercise program for 12 weeks or to a control group (n = 62) that did not receive any intervention. Muscle strength (dynamometer) and postural control (stabilometric platform) were evaluated before and immediately after an intervention period. The main findings of this study suggest that the women in the experimental group had improvements in muscle strength, mean velocity of the displacement of the center of pressure (CoP) with both eyes open and closed, and the surface sway area covered by the CoP, as well as the mediolateral and anteroposterior oscillations of the CoP, only with eyes open. The results of the present study determined that a 12 week Qigong exercise program has beneficial effects on muscle strength and postural control of middle-aged and older postmenopausal Spanish women.

scholarly journals Application of Real-Time Visual Feedback System in Balance Train-ing of the Center of Pressure with Smart Wearable Devices in Women: A Randomized Controlled Trial

2020 ◽  
Author(s):  
I-Lin Wang ◽  
Li-I Wang ◽  
Yang Liu ◽  
Shi-Jie Xue ◽  
Rui Hu ◽  
...  
Keyword(s):  
Real Time ◽  
Visual Feedback ◽  
Interaction Effect ◽  
Center Of Pressure ◽  
Balance Training ◽  
Training Group ◽  
Wearable Devices ◽  
Control Group ◽  
Significant Difference ◽  
Smart Wearable

This study aims to explore the effect of real-time visual feedback (VF) information of the pres-sure of center (COP) provided by intelligent insoles on balance training in a one leg stance (OLS) and tandem stance (TS) posture. Thirty healthy female college students were randomly assigned to the visual feedback balance training group (VFT), non-visual feedback balance training group (NVFT), and control group (CG). The balance training includes: OLS, tandem Stance (dominant leg behind, TSDL), tandem stance (non-dominant leg behind, TSNDL). The training lasted 4 weeks, the training lasts 30 minutes at an interval of 1 days. There was a sig-nificant difference in the interaction effect between Groups*Times of the COP parameters (p&lt;0.05) for OLS. There was no significant difference in the interaction effect between Groups*Times of the COP parameters (p&gt;0.05) for TS. The main effect of the COP parameters was a significant difference in Times (p&lt;0.05). The COP displacement, velocity, radius, and area in VFT significantly decreased after training (p &lt; 0.05). Therefore, the visual feedback technology of intelligent auxiliary equipment during balance training can enhance the benefit of training. The use of smart wearable devices in OLS balance training may improve the visual and physical balance integration ability.

scholarly journals The Effects of Abdominal Hypopressive Training on Postural Control and Deep Trunk Muscle Activation: A Randomized Controlled Trial

2021 ◽  
Vol 18 (5) ◽  
pp. 2741
Author(s):  
María del Mar Moreno-Muñoz ◽  
Fidel Hita-Contreras ◽  
María Dolores Estudillo-Martínez ◽  
Agustín Aibar-Almazán ◽  
Yolanda Castellote-Caballero ◽  
...  
Keyword(s):  
Postural Control ◽  
Muscle Activation ◽  
Center Of Pressure ◽  
Controlled Trial ◽  
Trunk Muscle ◽  
Posture Control ◽  
Trunk Muscles ◽  
Control Group ◽  
Female Population ◽  
Imaging Results

Background: Abdominal Hypopressive Training (AHT) provides postural improvement, and enhances deep trunk muscle activation. However, until recently, there was a lack of scientific literature supporting these statements. The major purpose of this study was to investigate the effect of AHT on posture control and deep trunk muscle function. Methods: 125 female participants aged 18–60 were randomly allocated to the Experimental Group (EG), consisting of two sessions of 30 min per week for 8 weeks of AHT, or the Control Group (CG), who did not receive any treatment. Postural control was measured with a stabilometric platform to assess the static balance and the activation of deep trunk muscles (specifically the Transverse Abdominal muscle (TrA)), which was measured by real-time ultrasound imaging. Results: The groups were homogeneous at baseline. Statistical differences were identified between both groups after intervention in the Surface of the Center of Pressure (CoP) Open-Eyes (S-OE) (p = 0.001, Cohen’s d = 0.60) and the Velocity of CoP under both conditions; Open-Eyes (V-OE) (p = 0.001, Cohen´s d = 0.63) and Close-Eyes (V-CE) (p = 0.016, Cohen´s d = 0.016), with the EG achieving substantial improvements. Likewise, there were statistically significant differences between measurements over time for the EG on S-OE (p < 0.001, Cohen´s d = 0.99); V-OE (p = 0.038, Cohen´s d = 0.27); V-CE (p = 0.006, Cohen´s d = 0.39), anteroposterior movements of CoP with Open-Eyes (RMSY-OE) (p = 0.038, Cohen´s d = 0.60) and activity of TrA under contraction conditions (p < 0.001, Cohen´s d = 0.53). Conclusions: The application of eight weeks of AHT leads to positive outcomes in posture control, as well as an improvement in the deep trunk muscle contraction in the female population.

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