Sensory neuroprosthesis improves postural stability during Sensory Organization Test in lower-limb amputees

Balance is accomplished by the congruent integration of visual, vestibular and somatosensory input and the execution of adequate control movements. With increasing age, nonlinear dynamics of central control systems become more regular. In unilateral vestibular dysfunction, sensory input to central systems is similarly less complex, because of one sided reduction of information influx. This study aimed to increase postural stability in patients with vestibular asymmetry and resulting disequilibrium by implementing a computerized visual training method relying on the principles of stochastic resonance. 24 subjects (average age 64a, 31–78a, 15 women, 9 men), with minimum 3 months of persisting disequilibrium due to vestibular dysfunction, were either treated with computerized optokinetic therapy (COKT), or solely observed. Treated patients were requested to read texts, stochastically moving in a previously defined matrix, during 10 sessions over three weeks. The Sensory Organization Test (SOT) was used for comparative posturographic measurements. COKT patients showed significant improvement in conditions 4, 6 and composite score. A significant post-therapeutic difference was seen between therapy and control groups in conditions 1, 6 and composite score. The results show a clinical benefit and we conclude COKT to be an effective rehabilitation method in patients with chronic disequilibrium.

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Concurrent validity of the Sensory Organization Test measures in unilateral transtibial amputees

Prosthetics and Orthotics International ◽

10.1177/0309364612448391 ◽

2012 ◽

Vol 37 (1) ◽

pp. 65-69 ◽

Cited By ~ 3

Author(s):

Prasath Jayakaran ◽

Gillian M Johnson ◽

S John Sullivan

Keyword(s):

Concurrent Validity ◽

Rank Correlation ◽

Correlation Coefficients ◽

Sensory Organization Test ◽

Spearman’S Rank Correlation ◽

Sensory Organization ◽

Clinical Measures ◽

Transtibial Amputees ◽

Lower Limb Amputees ◽

Strategy Score

Background and Aim: The physical asymmetries associated with a prosthesis raises the question of validity of the Sensory Organization Test (SOT) measures (equilibrium score (ES) and strategy score (SS)) in lower limb amputees. This study explores the validity of these measures in transtibial amputees by correlating with their corresponding centre of pressure (COP) excursion/velocity measures. Technique: Fifteen transtibial amputees (69.5 ± 6.5 years) completed three trials for each of the six SOT conditions. Discussion: The Spearman’s rank correlation coefficients between ESs and global COP excursion/velocity measures ranged from 0.52 to 0.71 for Conditions 1, 4 and 5, 0.79 to 0.85 for Conditions 2 and 3, and 0.39 to 0.43 for Condition 6. The coefficients for SSs ranged between 0.78 and 0.97 for Conditions 1 to 5 and 0.55 to 0.67 for Condition 6. The corresponding sound and prosthetic side COP variables demonstrated varying strengths of association with ES and SS. Clinical relevance Of the two clinical measures examined, the SSs are strongly reflective of COP excursion/velocity measures and these findings have application in the interpretation of SOT when evaluating balance in transtibial amputees.

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Normative Data for the NeuroCom® Sensory Organization Test in Subjects Aged 80–89 Years

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2021.761262 ◽

2021 ◽

Vol 15 ◽

Author(s):

Laura Perucca ◽

Antonio Robecchi Majnardi ◽

Stefano Scarano ◽

Silvia Frau

Keyword(s):

Postural Stability ◽

Normative Data ◽

Total Population ◽

Balance Control ◽

Cross Sectional Study ◽

Healthy Population ◽

Risk Of Falling ◽

Sensory Organization Test ◽

Cross Sectional ◽

Sensory Organization

Aging is known to increase the risk of falling. In older people, whose share in the total population is rising sharply, the Sensory Organization Test (SOT, Equitest NeuroCom) is a useful tool during rehabilitation and in clinical research for assessing postural stability, risk of falling, and balance improvement. Normative data for the SOT in the healthy population older than 79 years have not been previously published. We recruited 53 recreationally active healthy subjects aged 80 years and older from the general population in a cross-sectional study. We presented the normative data for SOT for the 80–84 and 85–89 years groups. Our results showed that the “vestibular” balance control tended to be affected by aging more than the vision and proprioception-based systems. A striking reduction in performance after the age of 85 years was observed. These findings will be useful for clinical and research purposes.

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Normative Data for the NeuroCom Sensory Organization Test in US Military Special Operations Forces

Journal of Athletic Training ◽

10.4085/1062-6050-52.1.05 ◽

2017 ◽

Vol 52 (2) ◽

pp. 129-136 ◽

Cited By ~ 8

Author(s):

Erin R. Pletcher ◽

Valerie J. Williams ◽

John P. Abt ◽

Paul M. Morgan ◽

Jeffrey J. Parr ◽

...

Keyword(s):

Postural Stability ◽

Normative Data ◽

Clinical Decision Making ◽

Acute Injury ◽

Sensory Organization Test ◽

Normative Database ◽

Special Operations ◽

Sensory Organization ◽

Us Military ◽

Special Operations Forces

Context: Postural stability is the ability to control the center of mass in relation to a person's base of support and can be affected by both musculoskeletal injury and traumatic brain injury. The NeuroCom Sensory Organization Test (SOT) can be used to objectively quantify impairments to postural stability. The ability of postural stability to predict injury and be used as an acute injury-evaluation tool makes it essential to the screening and rehabilitation process. To our knowledge, no published normative data for the SOT from a healthy, highly active population are available for use as a reference for clinical decision making. Objective: To present a normative database of SOT scores from a US Military Special Operations population that can be used for future comparison. Design: Cross-sectional study. Setting: Human performance research laboratory. Patients or Other Participants: A total of 542 active military operators from Naval Special Warfare Combatant-Craft Crewmen (n = 149), Naval Special Warfare Command, Sea, Air, and Land (n = 101), US Army Special Operations Command (n = 171), and Air Force Special Operations Command (n = 121). Main Outcome Measure(s): Participants performed each of the 6 SOT conditions 3 times. Scores for each condition, total equilibrium composite score, and ratio scores for the somatosensory, visual, and vestibular systems were recorded. Results: Differences were present across all groups for SOT conditions 1 (P < .001), 2 (P = .001), 4 (P > .001), 5 (P > .001), and 6 (P = .001) and total equilibrium composite (P = .000), visual (P > .001), vestibular (P = .002), and preference (P > .001) NeuroCom scores. Conclusions: Statistical differences were evident in the distribution of postural stability across US Special Operations Forces personnel. This normative database for postural stability, as assessed by the NeuroCom SOT, can provide context when clinicians assess a Special Operations Forces population or any other groups that maintain a high level of conditioning and training.

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Improving Postural Stability among Amputees by Tactile Sensory Substitution

10.21203/rs.3.rs-364267/v1 ◽

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.

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The Nintendo® Wii Fit Balance Board can be used as a portable and low-cost posturography system with good agreement compared to established systems

European Journal of Medical Research ◽

10.1186/s40001-020-00445-y ◽

2020 ◽

Vol 25 (1) ◽

Author(s):

Ben Rohof ◽

Marcel Betsch ◽

Björn Rath ◽

Markus Tingart ◽

Valentin Quack

Keyword(s):

Gold Standard ◽

Scoring System ◽

Postural Stability ◽

Demographic Data ◽

Sensory Organization Test ◽

Level Of Evidence ◽

Wii Fit ◽

Sensory Organization ◽

Balance Game ◽

Balance Board

Abstract Background Almost all epidemiological studies over the past 40 years have determined that the incidence of fragility fractures is increasing. Therefore, the assessment of postural stability and monitoring any progress during balance training for geriatric patients to prevent falls are becoming more important. The Nintendo® Wii Fit Balance Board, with its integrated software and scoring system, might be a cheap and easily accessible tool for this purpose. Methods This prospective study analyzed the diagnostic value of the Wii Fit Balance Board in 41 healthy subjects using two measurements: the yoga task “tree,” which is performed in one-leg stance; and the balance game “table tilt.” Our investigation compared these tasks to two established, regularly used systems, the MFT-S3 Check and the Posturomed, by looking for correlation and agreement, using Bland–Altman plots, as well as for differences to demographic data. All measurement tools were also compared to the Sensory Organization Test—the gold standard for detecting impaired balance. Results We found a moderate correlation between the yoga exercise “tree” and the Sensory Organization Test (correlation coefficient r = 0.514, p = 0.001) as well as the MFT-S3 Check (r = 0.356–0.472, p = 0.002–0.022) and the Posturomed (r = 0.345, p = 0.027). However, results from the balance game “table tilt” did not show a significant correlation with those of the systems to which we compared it (p = 0.301–0.953). Conclusions According to the literature, the raw data from the Wii Fit Balance Board are comparable to that obtained by laboratory-grade force platforms. We have found, however, that the yoga pose “tree,” as integrated into the Nintendo® Wii Fit Balance Board with its own scoring system, also correlates with the gold-standard Sensory Organization Test. It also correlates with two frequently used diagnostic and therapeutic devices. We, therefore, conclude that the Wii Fit Balance Board is suitable for the evaluation of postural stability and may be useful in preventing falls among the geriatric population. Level of evidence 2b.

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Poster 35 Evaluation of Correlation Between the Modified Balance Error Scoring System and the Sensory Organization Test as Measures of Postural Stability

PM&R ◽

10.1016/j.pmrj.2011.08.091 ◽

2011 ◽

Vol 3 ◽

pp. S188-S188

Author(s):

Elena J. Jelsing ◽

Jonathan Finnoff ◽

John H. Hollman ◽

Desiree J. Lanzino ◽

Cara Prideaux ◽

...

Keyword(s):

Scoring System ◽

Postural Stability ◽

Sensory Organization Test ◽

Sensory Organization ◽

Balance Error Scoring System ◽

Balance Error

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Stroboscopic Vision as a Dynamic Sensory Reweighting Alternative to the Sensory Organization Test

Journal of Sport Rehabilitation ◽

10.1123/jsr.2019-0466 ◽

2021 ◽

Vol 30 (1) ◽

pp. 166-172

Author(s):

Kyung-Min Kim ◽

Joo-Sung Kim ◽

Jeonghoon Oh ◽

Dustin R. Grooms

Keyword(s):

Repeated Measures ◽

Postural Stability ◽

Center Of Pressure ◽

Postural Instability ◽

Clinical Test ◽

Sensory Organization Test ◽

Sensory Organization ◽

Unstable Surface ◽

Significant Difference ◽

The Difference

Context: The sensory organization test (SOT) is a standard for quantifying sensory dependence via sway-referenced conditions (sway-referenced support and sway-referenced vision [SRV]). However, the SOT is limited to expensive equipment. Thus, a practical version of the SOT is more commonly employed—the clinical test for sensory integration in balance; however, it fails to induce postural instability to the level of SRV. Objective: Determine if Stroboscopic vision (SV), characterized by intermittent visual blocking, may provide an alternative to the SRV for assessing postural stability. Design: Descriptive laboratory study. Setting: Research laboratory. Participants: Eighteen participants (9 males, 9 females; age = 22.1 [2.1] y, height = 169.8 [8.5] cm, weight = 66.5 [10.6] kg). Intervention: Participants completed the SOT conditions, and then repeated SOT conditions 2 and 5 with SV created by specialized eyewear. Main Outcome Measures: A repeated-measures analysis of variance was completed on the time-to-boundary metrics of center-of-pressure excursion in the anteroposterior and mediolateral directions in order to determine the difference between the full-vision, SV, and SRV conditions. Results: Postural stability with either SRV or SV was significantly worse than with full vision (P < .05), with no significant difference between SV and SRV (P > .05). Limits of agreement analysis revealed similar effects of SV and SRV except for unstable surface mediolateral time-to-boundary. Conclusions: In general, SV was found to induce a degree of postural instability similar to that induced by SRV, indicating that SV could be a portable and relatively inexpensive alternative for the assessment of sensory dependence and reweighting.

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Sensory Organization Test Conditions Influence Postural Strategy Rather than Footwear or Workload

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph181910511 ◽

2021 ◽

Vol 18 (19) ◽

pp. 10511

Author(s):

Harish Chander ◽

Sachini N. K. Kodithuwakku Arachchige ◽

Alana J. Turner ◽

Reuben F. Burch V ◽

Jennifer C. Reneker ◽

...

Keyword(s):

Repeated Measures ◽

Postural Stability ◽

Sensory Feedback ◽

Sensory Organization Test ◽

Ankle Strategy ◽

Sensory Organization ◽

Test Conditions ◽

Repeated Measures Analysis ◽

Alpha Level ◽

Occupational Workload

Background: Postural strategies such as ankle, hip, or combined ankle-hip strategies are used to maintain optimal postural stability, which can be influenced by the footwear type and physiological workload. Purpose: This paper reports previously unreported postural strategy scores during the six conditions of the sensory organization test (SOT). Methods: Fourteen healthy males (age: 23.6 ± 1.2 years; height: 181 ± 5.3 cm; mass: 89.2 ± 14.6 kg) were tested for postural strategy adopted during SOT in three types of occupational footwear (steel-toed work boot, tactical work boot, low-top work shoe) every 30 min during a 4-h simulated occupational workload. Postural strategy scores were analyzed using repeated measures analysis of variance at 0.05 alpha level. Results: Significant differences among postural strategy scores were only evident between SOT conditions, and but not between footwear type or the workload. Conclusions: Findings indicate that occupational footwear and occupational workload did not cause a significant change in reliance on postural strategies. The significant changes in postural strategy scores were due to the availability of accurate and/or conflicting sensory feedback during SOT conditions. In SOT conditions where all three types of sensory feedback was available, the ankle strategy was predominantly adopted, while more reliance on hip strategy occurred in conditions with absent or conflicting sensory feedback.

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Adaptive Foot in Lower-Limb Prostheses

Journal of Robotics ◽

10.1155/2017/9618375 ◽

2017 ◽

Vol 2017 ◽

pp. 1-15 ◽

Cited By ~ 2

Author(s):

Thilina H. Weerakkody ◽

Thilina Dulantha Lalitharatne ◽

R. A. R. C. Gopura

Keyword(s):

Lower Limb ◽

Uneven Surface ◽

Design Concepts ◽

Human Foot ◽

Future Developments ◽

Adaptive Capabilities ◽

Adaptive Nature ◽

Lower Limb Amputees ◽

Artificial Prosthesis ◽

Lower Limb Prostheses

The human foot consists of complex sets of joints. The adaptive nature of the human foot enables it to be stable on any uneven surface. It is important to have such adaptive capabilities in the artificial prosthesis to achieve most of the essential movements for lower-limb amputees. However, many existing lower-limb prostheses lack the adaptive nature. This paper reviews lower-limb adaptive foot prostheses. In order to understand the design concepts of adaptive foot prostheses, the biomechanics of human foot have been explained. Additionally, the requirements and design challenges are investigated and presented. In this review, adaptive foot prostheses are classified according to actuation method. Furthermore, merits and demerits of present-day adaptive foot prostheses are presented based on the hardware construction. The hardware configurations of recent adaptive foot prostheses are analyzed and compared. At the end, potential future developments are highlighted.

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