Reduction of Postural Sway by Use of a Vibrotactile Balance Prosthesis Prototype in Subjects with Vestibular Deficits

2003 ◽  
Vol 112 (5) ◽  
pp. 404-409 ◽  
Author(s):  
Erna Kentala ◽  
Jason Vivas ◽  
Conrad Wall
Keyword(s):  
Postural Sway ◽  
Body Tilt ◽  
Vibrotactile Feedback ◽  
Dynamic Posturography ◽  
Sensory Organization ◽  
The Subject ◽  
Linear Accelerometer ◽  
Subject Performance ◽  
Vestibular Deficit ◽  
Anterior Posterior

To evaluate the effectiveness of a prototype vibrotactile balance prosthesis in maintaining balance during dynamic posturography, we studied 6 subjects with unilateral or bilateral vestibular deficit by means of Equitest computerized dynamic posturography (CDP). Their anterior-posterior (AP) sway at the small of the back was measured with a micromechanical rate gyroscope and a linear accelerometer. The resulting tilt estimate was displayed by a vibrotactile array attached to the torso. The vibration served as tilt feedback to the subject. Subject performance was evaluated with the tilt performance index (TPI), which is the inverse of the root-mean-square of tilt. We found that the balance prosthesis reduced the subjects' AP sway. The subjects' results without the balance prosthesis on CDP sensory organization tests (SOTs) 5 and 6 were compared to results with the prosthesis. The average TPI increased significantly (p < .05) when vibrotactile feedback was used as compared to the unaided condition. This finding was true for both SOTs 5 and 6. We conclude that vibrotactile feedback of estimated AP body tilt improved the subjects' ability to perform selected CDP tests. Some of the subjects were able to stand throughout the test with the device turned on, whereas they otherwise constantly fell.

Control of sway using vibrotactile feedback of body tilt in patients with moderate and severe postural control deficits

2005 ◽  
Vol 15 (5-6) ◽  
pp. 313-325
Author(s):  
C. Wall ◽  
E. Kentala
Keyword(s):  
Postural Control ◽  
Postural Stability ◽  
Body Motion ◽  
Body Tilt ◽  
Joint Movement ◽  
Foot Pressure ◽  
Eyes Closed ◽  
The Subject ◽  
Anterior Posterior ◽  
Vibrotactile Display

We evaluated the effect of the vibrotactile display of body tilt upon the postural stability of vestibulopathic subjects during standing. Two groups were studied: those with moderate and with severe deficits as defined by postural stability test scores. They were studied under conditions of distorted sensory input, and during anterior-posterior perturbations. Seventeen subjects, with uni- or bilateral vestibular deficits, as determined by electronystagmography and vertical axis rotation, were tested using Equitest® computerized dynamic posturography (CDP). Based on their performance on the CDP they were divided into two groups having either moderate (nine subjects) or severe (eight subjects) postural control deficits. Their anterior-posterior (A/P) body motion at the waist was measured with a micromechanical rate gyroscope and a linear accelerometer. The resulting tilt estimate was displayed by a vibrotactile array attached to the torso. The vibration served as a tilt feedback to the subject. The subject's performance was evaluated using the root-mean-square (RMS) of both the A/P body motion and center-of-pressure (CoP) estimates. Sensory distortions were introduced using the Equitest® Sensory Organization Tests (SOT). These tests are designed to distort A/P sensory inputs while standing. The SOT 5 distorts proprioceptive information about ankle joint movement, while the subject stands eyes-closed on a moving support platform that measures foot pressure. The SOT 6 adds distorted visual information about body movement instead of testing with eyes closed. Perturbations were introduced using the Equitest® Motor Control Tests (MCT). These move the support platform forward or backward with small, medium and large displacements in the horizontal plane while measuring subjects' foot pressure responses. We used the medium and large backward tests. Vibrotactile display of body tilt reduced the subjects' A/P sway and improved their balance. The finding was more evident for those subjects with severe deficits than those moderate ones. This trend was found for both SOT 5 and 6, as well as the medium and large MCT. Additionally, during the MCT, the peak deflection and mean recovery time also decreased significantly.

Ankle Joint Proprioception and Postural Control in Basketball Players with Bilateral Ankle Sprains

2005 ◽  
Vol 33 (8) ◽  
pp. 1174-1182 ◽  
Author(s):  
Amy S. N. Fu ◽  
Christina W. Y. Hui-Chan
Keyword(s):  
Standard Deviation ◽  
Postural Control ◽  
Ankle Joint ◽  
Postural Sway ◽  
Plantar Flexion ◽  
Ankle Sprains ◽  
Sensory Organization Test ◽  
Basketball Players ◽  
Dynamic Posturography ◽  
Sensory Organization

Background Deficiencies in ankle proprioception and standing balance in basketball players with multiple ankle sprains have been reported in separate studies. However, the question of how ankle proprioceptive inputs and postural control in stance are related is still unclear. Hypothesis Ankle repositioning errors and the amount of postural sway in stance are increased in basketball players with multiple ankle sprains. Study Design Controlled laboratory study. Methods Twenty healthy male basketball players and 19 male basketball players who had suffered bilateral ankle sprains within the past 2 years were examined. Both groups were similar in age. Passive ankle joint repositioning errors at 5° of plantar flexion were used to test for ankle joint proprioception. The Sensory Organization Test was applied with dynamic posturography to assess postural sway angle under 6 sensory conditions. Results A significant increase in ankle repositioning errors was demonstrated in basketball players with bilateral ankle sprains (P < .05). The mean errors in the right and left ankles were increased from 1.0° (standard deviation, 0.4°) and 0.8° (standard deviation, 0.2°), respectively, in the healthy players to 1.4° (standard deviation, 0.7°) and 1.1° (standard deviation, 0.5°) in the injured group. A significant increase in the amount of postural sway in the injured subjects was also found in conditions 1, 2, and 5 of the Sensory Organization Test (P < .05). Furthermore, there were positive associations between averaged errors in repositioning both ankles and postural sway angles in conditions 1, 2, and 3 of the Sensory Organization Test (r = 0.39-0.54, P < .05). Conclusions Ankle repositioning errors and postural sway in stance increased in basketball players with multiple ankle sprains. A positive relationship was found between these 2 variables. Clinical Relevance Such findings highlight the need for the rehabilitation of patients with multiple ankle sprains to include proprioceptive and balance training.

scholarly journals Altering Visual Feedback Conditions Impacts Postural Sway Performance in Children After Controlling for Body Mass Index and Habitual Physical Activity

2017 ◽  
Vol 5 (2) ◽  
pp. 267-279 ◽  
Author(s):  
Michael Duncan ◽  
Elizabeth Bryant ◽  
Mike Price ◽  
Samuel Oxford ◽  
Emma Eyre ◽  
...  
Keyword(s):  
Physical Activity ◽  
Body Mass Index ◽  
Body Mass ◽  
Visual Feedback ◽  
Postural Sway ◽  
Habitual Physical Activity ◽  
Eyes Closed ◽  
Computerized Posturography ◽  
Eyes Open ◽  
Anterior Posterior

This study examined postural sway in children in eyes open (EO) and eyes closed (EC) conditions, controlling for body mass index (BMI) and physical activity (PA). Sixty two children (aged 8–11years) underwent sway assessment using computerized posturography from which 95% ellipse sway area, anterior/posterior (AP) sway, medial/lateral (ML) sway displacement and sway velocity were assessed. Six trials were performed alternatively in EO and EC. BMI (kg/m2) was determined from height and mass. PA was determined using sealed pedometry. AP amplitude (p = .038), ML amplitude (p = .001), 95% ellipse (p = .0001), and sway velocity (p = .012) were higher in EC compared with EO conditions. BMI and PA were not significant as covariates. None of the sway variables were significantly related to PA. However, sway velocity during EO (p = .0001) and EC (p = .0001) was significantly related to BMI. These results indicate that sway is poorer when vision is removed, that BMI influences sway velocity, but that pedometer-assessed PA was not associated with postural sway.

Head-Trunk Coordination During Linear Anterior-Posterior Translations

2003 ◽  
Vol 89 (4) ◽  
pp. 1891-1901 ◽  
Author(s):  
Emily A. Keshner
Keyword(s):  
Vestibular System ◽  
Healthy Subjects ◽  
Low Frequency ◽  
Head Acceleration ◽  
Response Latencies ◽  
Distraction Task ◽  
Analysis System ◽  
Post Hoc ◽  
Linear Accelerometer ◽  
Anterior Posterior

The purpose of this study was to evaluate the relative contributions of inputs from the vestibular system and the trunk to head-trunk coordination. Twelve healthy adults and 6 adults with diminished bilateral labyrinthine input (LD) were seated with their trunk either fixed to the seat or free to move. Subjects received 10-cm, 445-cm/s2 anterior-posterior ramps and 0.35- to 4.05-Hz sum-of-sines translations while performing a mental distraction task in the dark. Kinematics of the head and trunk were derived from an Optotrak motion analysis system and a linear accelerometer placed on the head. EMG signals were collected from neck and paraspinal muscles. Data were tested for significance with multivariate ANOVA (MANOVA) and Bonferroni post hoc analyses. Initial linear and angular head acceleration directions differed in healthy subjects when the trunk was fixed or free, but did not differ in LD subjects. Peak head angular accelerations were significantly greater with the trunk fixed than when free, and were greater in LD than in control subjects. EMG response latencies did not differ when the trunk was fixed or free. Low-frequency phase responses in the healthy subjects were close to 90° and had a delayed descent as frequency increased, suggesting some neural compensation that was absent in the LD subjects. Results of this study revealed a strong initial reliance on system mechanics and on signals from segmental receptors. The vestibular system may act to damp later response components and to monitor the position of the head in space secondary to feedback from segmental proprioceptors rather than to generate the postural reactions.

scholarly journals A Kinesthetic Model Demonstrating Molecular Interactions Involved in Anterior-Posterior Pattern Formation in Drosophila

2008 ◽  
Vol 7 (1) ◽  
pp. 74-81
Author(s):  
Kristin R. Douglas
Keyword(s):  
Developmental Biology ◽  
Molecular Interactions ◽  
Protein Interactions ◽  
Cell Biology ◽  
Three Dimensional ◽  
Introductory Courses ◽  
The Subject ◽  
Cellular Components ◽  
Anterior Posterior ◽  
Anterior Posterior Axis

Prerequisites for the Developmental Biology course at Augustana College are introductory courses in zoology and cell biology. After introductory courses students appreciate the fact that proteins have three-dimensional structures; however, they often fail to recognize how protein interactions with other cellular components can lead to specific cellular responses. One of the first topics covered in Augustana's Developmental Biology course is anterior-posterior axis determination in Drosophila. In the past, the subject was taught with a series of graphs demonstrating mRNA and protein concentrations along the anterior-posterior axis. However, this pedagogy was too conceptual for the majority of students enrolled in the course. To aid their understanding, a kinesthetic model of the molecular interactions involving bicoid, nanos, hunchback, and caudal transcripts and proteins utilizing colored pipe cleaners and beads was created. Students model molecular interactions between proteins (beads) and transcripts (pipe cleaners) by placing the appropriate bead on the appropriate pipe cleaner. After working with the model, the concept of molecular interactions became more concrete to students, and they were able to conceptualize anterior-posterior axis determination in Drosophila more clearly. Throughout the rest of the course, students were able to understand molecular interactions without the aid of additional models.

The D+R Balance application: a novel method of assessing postural sway

2015 ◽  
Vol 129 (8) ◽  
pp. 773-778 ◽  
Author(s):  
C Yvon ◽  
A Najuko-Mafemera ◽  
R Kanegaonkar
Keyword(s):  
Healthy Volunteers ◽  
Feasibility Study ◽  
Postural Sway ◽  
Dynamic Posturography ◽  
Eyes Closed ◽  
Novel Method ◽  
Iphone Application ◽  
Romberg Test ◽  
Potential Use ◽  
Hard Floor

AbstractBackground:Postural sway can be assessed clinically using the Romberg test, or quantified using dynamic posturography. We assessed the potential use of a novel iPhone application as a method of quantifying sway.Methods:Fifty healthy volunteers performed the Romberg and tandem Romberg tests on a hard floor and on foam in soundproofed and normal clinic rooms. Postural sway was recorded using the D+R Balance application and data were compared using pairedt-tests.Results:Significantly more postural sway was noted in participants when standing with their eyes closed and feet in the ‘tandem’ positionvsfeet together; standing with their eyes closed on foamvson the floor; and standing with their eyes closed on foam with feet in the tandem positionvson the floor with feet together.Conclusion:This feasibility study suggests that the iPhone D+R Balance application deserves further investigation as a means of assessing postural sway and may provide an alternative to current dynamic posturography systems.

scholarly journals The Effect of a Second Runner on Pacing Strategy and RPE During a Running Time Trial

2012 ◽  
Vol 7 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Deryn Bath ◽  
Louise A. Turner ◽  
Andrew N. Bosch ◽  
Ross Tucker ◽  
Estelle V. Lambert ◽  
...  
Keyword(s):  
Heart Rate ◽  
Time Trial ◽  
Subjective Assessment ◽  
Running Speed ◽  
Male Athletes ◽  
Pacing Strategy ◽  
Significant Difference ◽  
The Subject ◽  
Performance Times ◽  
Subject Performance

Purpose:The aim of this study was to examine performance, pacing strategy and perception of effort during a 5 km time trial while running with or without the presence of another athlete.Methods:Eleven nonelite male athletes participated in five 5 km time trials: two self-paced, maximal effort trials performed at the start and end of the study, and three trials performed in the presence of a second runner. In the three trials, the second runner ran either in front of the subject, behind the subject, or next to the subject. Performance times, heart rate, RPE, and a subjective assessment of the effect of the second runner on the athlete’s performance were recorded during each of the trials.Results:There was no significant difference in performance times, heart rate or RPE between any of the five trials. Running speed declined from the 1st to the 4th kilometer and then increased for the last kilometer in all five trials. Following the completion of all trials, 9 of the 11 subjects perceived it to be easier to complete the 5 km time trial with another runner in comparison with running alone.Conclusions:While the athletes perceived their performance to be improved by the presence of another runner, their pacing strategy, running speed, heart rate and RPE were not significantly altered. These findings indicate that an athlete’s subconscious pacing strategy is robust and is not altered by the presence of another runner.

scholarly journals LIMITATIONS OF VESTIBULAR REHABILITATION THERAPY USING DYNAMIC COMPUTERIZED POSTUROGRAPHY IN PATIENTS WITH CENTRAL VESTIBULAR SYNDROME

2015 ◽  
Vol 14 (3) ◽  
pp. 140-144
Author(s):  
Anamaria Andreia Ulmeanu ◽  
◽  
Andreea Didilescu ◽  
Raluca Enache ◽  
Gabriela Musat ◽  
...  
Keyword(s):  
Postural Stability ◽  
Maximum Amplitude ◽  
Vestibular Rehabilitation ◽  
Rehabilitation Program ◽  
Time Interval ◽  
Dynamic Posturography ◽  
Computerized Posturography ◽  
Risk Of Falls ◽  
Anterior Posterior

Objectives. To evaluate the importance of computerized dynamic posturography in vestibular rehabilitation (VR) of patients with central vestibular syndrome. Methods. The study included 30 patients with central vestibular syndrome with mean age (± SD) = 72.96 ± 11.97 which benefited from VR on a posturography platform between 2012-2014. All patients were evaluated using sensory integration tests. The parameters studied were: Romberg coefficient, statokinesigram (SKG), maximum amplitude of the degree of deviation in anterior-posterior and medial-lateral planes, SKG and the time interval of the rehabilitation program. Results. All of the analyzed parameters showed statistically significant results (p <0.05). The anterior-posterior and medio-lateral balance improved significantly at the end of the vestibular rehabilitation program and the parameters decreased to values close to normal. Conclusions. For patients with central vestibular syndrome, the vestibular rehabilitation improves postural stability and quality of life by reducing the risk of falls.

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