Balance is the ability to maintain an individual’s centre of mass over his or her base of support while standing. Ballet dancers have better balance than non-dancer control groups as they presented with better sensory-motor integrative skills when required to maintain a given posture for a longer period. To evaluate functional balance abilities, assessing individuals with above average balance abilities may provide valuable information about function. The balance of trained ballet dancers (N1) was investigated by comparing Sensory Organisaiton Test (SOT), Motor Control Test (MCT) and Limits of Stability (LOS) test results to matched non-trained individuals (N2). A quasi-experimental and two group design was used. Ten matched trained ballet dancers (N1) and 10 untrained individuals were included in the study. Trained ballet dancers (N1) had an average of 16.6 (± 4.24) years of experience, while non-trained individuals (N2) had none. No significant dufferences in demographic data was present between groups. Both groups reflected good overall balance and similar sensory organization. No differences in reflex latencies and weight symmetry of the left or right leg was present. Trained ballet dancers (N1) reflected higher response strength for medium forward translations (p.05) with the left leg, indicating poorer amplitude scaling in response to platform translations than those of non-trained individuals (N2). In non-trained individuals (N2), there was less variation in the response strength between legs. Research indicated that stretch reflex amplitude was attenuated as load stability was reduced. Co-contraction was also heightened as stability was reduced, but not enough to oppose the induced instability, probably due to feed-forward strategies instead of rapid involuntary feedback. Trained ballet dancers (N1) were able to extend further out of their Centre of Pressure (COP) than non-trained individual (N2) during forward (p<.05) and right forward (p<.05) movements. It was concluded that that for forward and right forward movements, ballet dancers used the feedback they received during the movements better than non-trained individuals (N2), resulting in a better awareness of where to go in space and how to reach that position after a subsequent attempt. This difference may be as a result of continuous training. Ballet training exercises can be used to rehabilitate individuals with impaired limits of stability. Further studies should be done on exactly which ballet training exercise results in increased limits of stability. / Mini Dissertation (MCommunication Pathology)--University of Pretoria, 2016. / Speech-Language Pathology and Audiology / MCommunication Pathology / Unrestricted

Background: Postural stability is maintained by the central integration of the multisensory inputs to produce motor outputs. When visual and somatosensory input is available and reliable, this reduces the postural control system’s reliance on the vestibular system. Despite this, vestibular loss can still cause severe postural dysfunction. Training one or more of the three sensory systems can alter sensory weighting and change postural behavior. Exercises to activate the vestibular system is one form of training which resolves symptoms of vestibular impairments. Vestibular activation exercises, including horizontal and vertical headshaking, influences vestibular-ocular and -motor responses and have been showed to be effective in vestibular rehabilitation. However, no study has employed a concurrent vestibular activation and weight shift postural training to realize a more effective rehabilitation method by positively influencing sensory reweighting mechanisms and vestibular reflexes. Our pilot study (n=33) has demonstrated significant postural stability improvement in the center of pressure (COP) medio-lateral standard deviation sway (ML Std) and multiscale entropy (MSE) sway velocity among the horizontal headshake group. This improvement was found in the vestibular and visual-vestibular conditions of the Sensory Organization Test (SOT) assessment when compared to a non-headshake training group and no training group (control). Aims: The main aim of this study was to assess sensory reweighting of postural control processing and vestibular-ocular and -motor responses after combined vestibular activation with postural training in healthy young adults. It was hypothesized that the effect of this training would significantly alter the pattern of sensory weighting by changing the ratio of visual, somatosensory and vestibular dependence needed to maintain postural stability, and significantly decrease vestibular responses. Methods: Forty-two young healthy individuals (22 females; 23.0+3.9 years [18-35 years]; 1.6+0.1 meters) were randomly assigned into four groups: 1) visual feedback weight shift training (WST) coupled with an active horizontal headshake (HHS), 2) same WST with vertical headshake (VHS), 3) WST with no headshake (NHS) and 4) no training/headshake control (CTL) groups. The headshake groups performed an intensive body weight shift training (WST) together with horizontal or vertical rhythmic headshake 30° in both directions in accordance to the beat of a metronome ranging from 80 to 120 beats per minute. The NHS group performed the WST with no headshake while the control did not perform any training. Five 15-minute training sessions were performed on consecutive days for one week with the weight shift exercises involving upright limits of stability activities on a flat surface, foam or rocker board. All groups performed baseline- and post-assessments including SOT and force plate platform up and down unpredictable ramp perturbations, coupled with electromyographic (EMG) and electro-oculographic (EOG) recordings. The video head impulse test (vHIT) system was also used to record horizontal VOR gain. Statistical analysis: A between- and within-group repeated measures ANOVA of 6 (3 visuals x 2 surfaces) conditions x 4 groups x 2 sessions was used to analyze five COP sway variables, the equilibrium and composite scores and sensory ratios of the SOT as well as EMG (onset, duration, peak amplitude, peak time and power spectral densities) signals and horizontal VOR gain. The five COP variables were: sway area, sway velocity, antero-posterior (AP) standard deviation, ML Std and MSE sway velocity. Similarly, COP variables, EMG, as well as EOG (angle in degrees) and vestibular reflex (vertical VOR, VCR and VSR gain) data during ramp perturbation trials were analyzed. Pearson product-moment correlation was used to evaluate the relationships between outcome measures. Alpha level will be set at p&lt;.05. Results: The concurrent vestibular and WST showed a significant somatosensory downweighting (p = .050) in the headshake groups compared to the other groups. The training also showed a significant decreased horizontal VOR gain (p = .040), faster automatic postural response (p = .003) with improved flexibility (p = .010) in the headshake groups. Muscle activation pattern in medial gastrocnemius (p = .033) and eye movement variability (p = .024) were significantly decreased in the headshake groups following training. Pearson correlations showed moderate associations between postural sway, eye movement variables and vestibular reflex gains. Specifically, there were negative associations between VOR gain versus postural sway (r = -0.460 – -0.553; p = &lt; .008), and eye movement variability versus postural sway (r = -0.404 – -0.521; p = &lt; .015), and positive associations between EMG peak amplitude versus postural sway (r = 0.435 – 0.498; p = &lt; .004) and eye movement variability (r = 0.467; p = .007). Conclusion: The concurrent vestibular activation and weight shift training modifies vestibular-dependent responses after the training intervention as evidenced in somatosensory downweighting, decreased VOR gain, decreased eye movement variability and better postural flexibility and faster automatic postural response. The findings suggest this is predominantly due to vestibular habituation and adaptation of VOR, VCR and VSR which induced sensory reweighting. The study also found moderate associations between postural measures and vestibular responses in vestibular reflex gains, eye movement variability and muscle activations. These findings may help predict postural changes through vestibular habituation and also provide insight into the behavior of eye movements and muscle activations following vestibular training. In addition, the findings may be used to guide development of a vestibular-postural rehabilitation intervention in impaired neurological populations, such as with vestibular disorders or sensory integration problems present in traumatic brain injuries. / Physical Therapy

Goal The goal of our pilot study was to evaluate the effect of short-term home based sensomotoric Training program (six weeks) in healthy adults on dynamic postural stability. We used the SOT at baseline and post the training program to evaluate the effect. Methodology The number of participants in this experiment was 10 healthy students, the number of males was 8 and 2 females, they were all between the age of 23 and 40 (mean 29.5 and ± S.D = 5.1 years). The sensory organization test was conducted at baseline and post the home based sensomotoric training program by using the dynamic posturography SMART Balance Master System (NeuroCom). The somatosensory (SOM), visual (VIS), vestibular (VEST), preference (PREF) and composite equilibrium outcome measures of the sensory organization test were evaluated. Results The VIS sensory system has significantly improved also the VEST sensory system with p-value < 0.05. The SOM sensory system had no significant improvement also the PREF sensory system with p-value > 0.05, while the overall composite equilibrium had a significant improvement with p-value > 0.05. Conclusion According to our findings the short-term home based sensomotoric training program has a positive effect in terms of improving the overall dynamic balance in healthy adults. Keywords Dynamic...

Title: Evaluation of postural stability of athletes - a literature review Objectives: Thesis will address retrieval processing rating Dynamic Postural Stability of athletes . Compares analysis or results of research or investigations of different laborers working with this theme. It also mentions tests and machines used in clinical practice. It also investigates in what sports was postural stability tested and how or with what results. The most advanced, currently the most recognized dynamic posturography with impartial value is EquiTest device from NeuroCom. Therefore, the practical part focuses primarily on the results of examination of this device and make statistics about that. Methods: The diploma thesis has descriptive and analytical character. It is elaborate as a literary review . Results: The study includes 142 studies, of which only 11 concern the assessment of postural stability of athletes. Sports disciplines include tennis, football, baseball, tai-chi, taekwondo, gymnastics, basketball, softball. Entire EquiTest testing battery (which contains 7 test in total - Sensory Organization Test, Motor Coordination and Control Test, Adaptation Test, Unilateral Stance Test, Limits Of Stability Test, Rhytmics Weight Shift, Weight Bearing Squat) is almost never used in assessments although it's a...

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L’instabilité posturale est fréquente chez les séniors et peut entrainer la chute. La chute chez les séniors est un problème majeur de santé publique. Les chiffres épidémiologiques sont éloquents : une personne sur trois âgées de plus de 70 ans fera une chute dans l’année. Les causes sont multifactorielles : ostéo-articulaire, visuelle, cognitive, vestibulaire…. Dans cette étude, nous nous sommes intéressés à l’évolution de la fonction des récepteurs vestibulaires périphériques avec l’âge et à la perception de rotation à partir des entrées canalaires horizontales (système vestibulaire central et projections vestibulaires corticales). Notre but est d’essayer de comprendre l’implication du vieillissement du système vestibulaire dans l’instabilité posturale des séniors. Au niveau périphérique, nous avons quantifié la fonction des canaux semi-circulaires horizontaux par le test calorique et le vidéo-head impulse test. La fonction des récepteurs otolithiques (utriculaire et sacculaire) a été évaluée par les potentiels évoqués myogéniques recueillis au niveau cervical (voies sacculo-spinales) et oculaire (voies utriculo-oculaires). Au niveau central, la perception de l’entrée vestibulaire canalaire horizontale a été appréciée après irrigation à l’eau chaude du conduit auditif externe en appliquant un score de perception (présence ou absence de sensation rotatoire). Finalement, l’équilibre a été quantifié grâce au test d’organisation sensorielle sur l’Equitest et grâce à un système que nous avons récemment mis au point en collaboration avec le Professeur Curthoys à Sydney, comprenant une Wii Balance Board, un tapis mousse et un masque de réalité virtuelle (Oculus Rift). Les résultats ont montré une diminution des réponses oculaires au test calorique après 70 ans mais une absence de baisse du gain du réflexe vestibulo-oculaire horizontal au vidéo-head impulse test. La fonction otolithique, sacculaire et utriculaire, est altérée avec l’âge quelle que soit la stimulation utilisée (aérienne ou osseuse). La perception de l’entrée vestibulaire canalaire horizontale induite par une stimulation calorique nous a permis de montrer pour la première fois que certains séniors ne percevaient pas la sensation de rotation malgré une réponse oculaire normale (vitesse maximale de la phase lente du nystagmus oculaire supérieure à 15°/s). Dans notre population, nous avons pu ainsi définir deux types de séniors : un groupe présentant une perception de vertige rotatoire et un groupe « négligeant » ne pouvant pas reconstruire une sensation rotatoire à partir des entrées vestibulaires canalaires horizontales. La comparaison de ces deux groupes de séniors appariés sur l’âge ne montre aucune différence de la fonction canalaire horizontale ni de la fonction otolithique sacculaire et utriculaire. Néanmoins, les séniors négligents présentent en majorité des performances anormales (chute ou score diminué) à l’Equitest notamment en conditions 5 et 6. De plus, leur score au DHI est plus élevé relevant ainsi le handicape ressenti par ces séniors à cause de leur instabilité. En conclusion, les troubles de l’équilibre chez certains seniors pourraient résulter en partie d’une dysfonction vestibulaire centrale. Des études ultérieures permettront de déterminer si l’augmentation du seuil de perception rotatoire est un bon facteur prédictif du risque de chute. / Postural instability is common in seniors and can lead to falls which seniors are a major problem for Public Health. Epidemiological studies clearly show the magnitude of this problem: one in three people aged than more 70 years will fall in a year. This is caused by multiple factors including: musculoskeletal, visual, cognition, vestibular… The present study concerns the effect of age on the vestibular peripheral receptors function and on the perception of rotation from horizontal canal inputs (central vestibular processing and vestibular cortical projection). The aim is to try to understand the vestibular mechanisms involved in postural instability and mobility with age. At the peripheral level, the horizontal canal function was assessed using caloric test and video-Head Impulse Test. Otolith function (saccular and utricular) was assessed using vestibular evoked myogenic potentials recorded at cervical level (sacculo-spinal pathways) and at ocular level (utriculo-ocular pathways). At the central level, perception of motion from vestibular horizontal canal inputs was studied after caloric stimulation with warm water using a subjective perceptual score (presence or absence of rotatory vertigo). Finally, postural equilibrium was assessed with the Sensory Organization Test on the Equitest machine and also with a new system developed in collaboration with Prof. Curthoys (Sydney) using a Wii Balance Board, a foam rubber pad and a virtual reality headset (Oculus Rift DK2). Results showed decreased ocular responses induced by caloric stimulation after 70 years of age but healthy horizontal gain of the vestibulo-ocular reflex assessed by video-head impulse testing. The otolithic (saccular and utricular) function is impaired with age for all the stimuli used (air or bone conducted). Perception of motion induced by caloric stimulation (vestibular horizontal canal inputs) allowed us to show for the first time that some seniors are unable to feel the induced rotatory vertigo even with normal ocular responses (peak of the slow phase eye velocity higher than 15°/s). We defined two types of seniors: one senior group having a normal feeling of vertigo and one senior ‘neglect’ group who did not feel any sensation of rotation from horizontal canal inputs. The comparison of these two age-matched groups showed no difference in horizontal canal function, or otolithic function. The majority of the ‘neglect’ seniors with an absence of perception exhibited falls or a decreased score in conditions 5 and 6 during the Equitest. Moreover, their DHI scores were higher, showing the handicap induced by postural instability in these seniors. In conclusion, postural instability and falls in seniors may result from central vestibular impairment (inadequate central processing). A prospective study is needed to determine whether the increase perceptual threshold of rotation could be a good predictor of fall risk in seniors.