Rehabilitation of Postural Control and Gait in Children with Cerebral Palsy: the Beneficial Effects of Trunk-Focused Postural Activities.

PURPOSE: In children with cerebral palsy (CP), with impaired trunk control and toe-walking, trunk-focused rehabilitation (TFR) based on postural activities was hypothesized to improve trunk postural control, early trunk deceleration, and ankle dorsiflexion braking during walking. Methods: Seventeen children with CP (5-12 years) walking autonomously were randomly assigned to TFR and then usual rehabilitation (TFR-UR) or vice versa (UR-TFR). RESULTS: Only after TFR was significant improvements in (i) the Trunk Control Measurement Scale score, postural sway on an unstable sitting device and standing, and (ii) early sternal and sacral decelerations and coupled negative ankle power due to plantar flexors. CONCLUSION: TFR improves trunk dynamics and consequently improves coupled toe-walking.

Intra-articular Injection of Bone Marrow Concentrate for Treatment of Patellofemoral Osteoarthritis: Preliminary Results Utilizing an Ultrasound-Guided Marrow Harvesting Technique.

OBJECTIVE: To assess the effectiveness of intra-articular injection of bone marrow concentrate (BMC) under ultrasound (US) guidance in the treatment of patellofemoral osteoarthritis (OA), with clinical and volumetric magnetic resonance (MR) imaging follow-up. METHODS: This retrospective study included 96 consecutive patients referred for US-guided intra-articular injection of BMC for symptomatic patellofemoral OA for which conservative treatment had failed. A control group of 21 patients with symptomatic patellofemoral OA was included for comparison. Data on International Knee Documentation Committee (IKDC), Visual Analog Scale (VAS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores as well as volumetric MR imaging (using T2 mapping sequence) were collected before and 12 months after injection, and the results were compared. RESULTS: No technical adverse events were noted during bone marrow aspiration, BMC preparation, or intra-articular injection of BMC. No clinical adverse events were reported during long-term follow-up. All mean scores improved between baseline and 12 months after intra-articular injection of BMC (VAS 5.5 to 3.6, P < .0001; WOMAC 36.8 to 22.2, P < .0001; and IKDC 41.8 to 58.2, P < .0001). MR imaging at 1 year of follow-up after BMC treatment showed no statistically significant difference in hyaline cartilage volume compared with that at the baseline (P = .690), suggesting stabilization of the cartilage degradation process. In contrast, the group of untreated patients showed a significant decrease in the cartilage volume (P = .001), corresponding to a cartilage loss of 6.9%. CONCLUSIONS: The results suggest that intra-articular injection of BMC under US guidance could be a promising option for the treatment of symptomatic patellofemoral OA and could promote the preservation of healthy residual cartilage volume.

Influence of body mobility on attention networks in school-aged prematurely born children: A controlled trial.

School-aged prematurely born children (PC) have a higher risk of academic difficulties, which may be partly explained by attention difficulties. It has been suggested that children's attentional performance might be influenced by their body posture and spontaneous body motion. The aim of this study (ClinicalTrials.gov - NCT03125447) was to test the influence of three body mobility conditions on the three functions of attention (alertness, orienting, and executive control) among school-aged PC vs. term-born children (TC). Notably, 21 PC and 21 TC performed the Attention Network Test for Children in three body mobility conditions, namely, sitting and standing imposed fixed postures and a free-to-move condition. The children's median reaction times were compared between trials (1) with and without alerting cues, (2) with valid and invalid orienting cues, and (3) with and without distracting information, to calculate the performance of alertness, orienting, and executive control, respectively. Results showed that with distracting information, PC exhibited significantly slower responses in the standing-still posture than in the sitting-still posture (1,077 ± 240 vs. 1,175 ± 273 ms, p < 0.05), but not TC. No difference was observed with the free-to-move condition. PC and TC did not significantly differ in alertness or orienting, regardless of body mobility condition. These data suggest that PC must use executive resources to stand still and maintain position, which impairs their performance during executive tasks. We speculate that these results may be related to less developed postural control and motor inhibition in PC.

Gastric Pneumatosis with Portal Venous Gas can be Treated Non-operatively: A Retrospective Multi-institutional Study.

BACKGROUND: Gastric pneumatosis (GP) is a rare radiologic finding with an unpredictable prognosis. The aim of this study was to identify mortality risk factors from patients presenting with GP on computed tomography (CT), and to develop a model which would allow us to predict which patients would benefit most from operative management. METHODS: Between 2010 and 2020, all CT-scan reports in four tertiary centers were searched for the following terms: "gastric pneumatosis," "intramural gastric air" or "emphysematous gastritis." The retrieved CT scans were reviewed by a senior surgeon and a senior radiologist. Relevant clinical and laboratory data for these patients were extracted from the institutions' medical records. RESULTS: Among 58 patients with GP, portal venous gas and bowel ischemia were present on CT scan in 52 (90%) and 17 patients (29%), respectively. The 30-day mortality rate was 31%. Univariate analysis identified the following variables as predictive of mortality at the time of the diagnosis of GP: abdominal guarding, hemodynamic instability, arterial lactate level >2 mmol/l, and the absence of gastric dilatation. Multivariable analysis identified the following variables as independent predictors of mortality: arterial lactate level (OR: 1.39, 95% CI: 1.07-1.79) and the absence of gastric dilatation (OR: 0.07, 95% CI: 0.01-0.79). None of the patients presenting with a baseline lactate rate<2 mmol/l died within 30 days following diagnosis, and no more than 17 patients out of 58 had bowel ischemia (29%). CONCLUSIONS: GP could be managed non-operatively, even in the presence of portal venous gas. However, patients with arterial lactate level>2 mmol/l, or the absence of gastric dilation should be surgically explored due to a non-negligible risk of mortality.

Body Mobility and Attention Networks in 6- to 7-Year-Old Children.

Learning in 6- to 7-year-old children is strongly influenced by three functions of attention: alertness, orienting, and executive control. These functions share a close relationship with body mobility, such as the posture adopted or a request to stay still during tasks. The aim of this study (ClinicalTrials.gov) was to analyze the influence of body posture (standing versus sitting) and the influence of these imposed postures compared to a free body mobility on attention functions in 6- to 7-year-old children. Twenty-one children (11 girls) with a mean age of 6.7±0.6years performed the Attention Network Test for Children in three-body mobility conditions: sitting still, standing still, and free to move. Three attentional scores were calculated which would separately reflect performance of alertness, orienting, and executive control. Overall, no difference in alertness performance was found between the three bodily mobility conditions. In addition, our results suggest a general poor orienting performance in children, whatever the body mobility condition, which might be related to their young age. Finally, children improved their executive control performance when they stood still, probably due to an improvement in arousal and mental state.

Trochanteric fractures treated by internal fixation using short intramedullary nails: Does the visual intraoperative estimation of the Tip-Apex Distance (TAD) concur with its digital postoperative measurement?

INTRODUCTION: The tip-apex distance (TAD) is the only predictor for mechanical failure after internal fixation of trochanteric fractures. The main objective of our study was to assess whether the intraoperative visual estimation of the TAD concurred with the measurement taken on postoperative digital X-rays. We hypothesized that there was a good concordance between these 2 different methods of measurement. MATERIALS AND METHODS: Patients with an isolated trochanteric fracture were included in our study. A hardcopy of the intraoperative X-rays were printed, and the TAD was calculated manually. Radiological and clinical follow-ups were scheduled at 6 weeks, 3 months and 6 months during which numerical measurements of the TAD were taken. We also recorded the fracture type (AO/OTA classification), degree of osteoporosis (Singh index), surgeon experience, age and ASA score. RESULTS: A total of 98 patients were included in our study. Of these, 70 had a 6-month follow-up and interpretable postoperative X-rays. The mean age was 87 years, with 77.14% women and a mean ASA score of 3. The coefficient of concordance between the intra and postoperative TAD was 0.7202 (95% CI=0.4905-0.9499). The secondary displacement rate was 3.28%. The univariate analysis showed no statistically significant association between an intraoperative TAD>25mm and fracture type (p=0.7290), degree of osteoporosis (p=0.5701) and surgeon experience (p=1). DISCUSSION/CONCLUSIONS: There was a high degree of concordance between intraoperative visual estimation of the TAD and its measurement on postoperative digital X-rays. The treatment of unstable fractures in osteoporotic bone by junior surgeons was not a risk factor for intraoperative TAD>25mm. It is therefore important to educate young surgeons on the concept of TAD and its intraoperative visual estimation technique as it ensures that the cephalic screw is positioned properly during the fixation of trochanteric fractures. LEVEL OF EVIDENCE: II.

Impaired postural control of axial segments in children with cerebral palsy.

BACKGROUND: Sensorimotor control of axial segments, which develops during childhood and is not mature until adolescence, is essential for the development of balance control during motor activities. Children with cerebral palsy (CP) have deficits in postural control when standing or walking, including less stabilization of the head and trunk which could affect postural control. RESEARCH QUESTION: Is dynamic stabilization of axial segments during an unstable sitting task deficient in children with CP compared to typically developing children? Is this deficit correlated with the deficit of postural control during standing? METHOD: Seventeen children with CP (GMFCS I-II) and 17 typically-developing children from 6 to 12 years old were rated on the Trunk Control Measurement Scale (TCMS). In addition, posturography was evaluated in participants while they maintained their balance in stable sitting, unstable sitting, and quiet standing, under "eyes open" and "eyes closed" conditions. In sitting tasks, the participants had to remain stable while being prevented from using the lower and upper limbs (i.e. to ensure the involvement of axial segments alone). RESULTS: Children with CP compared to TD children had significantly larger surface area, mean velocity and RMS values of CoP displacements measured during the unstable sitting task and the standing task, under both "eyes open" and "eyes closed" conditions. No significant group effects were observed during the stable sitting task. The TCMS total score was significantly lower, indicating trunk postural deficit, in the CP group than in the TD group and was significantly correlated with postural variables in the sitting and standing tasks. SIGNIFICANCE: Children with CP indeed have a specific impairment in the postural control of axial segments. Since the postural control of axial segments is important for standing and walking, its impairment should be taken into account in rehabilitation programs for children with CP.

Perceptual post-effects of left neck muscle vibration with visuo-haptic feedback in healthy individuals: A potential approach for treating spatial neglect.

Among the techniques used to reduce spatial neglect's symptoms, left neck muscle vibration (NMV) is alluring because it does not require the patient's attentional co-operation. The aim of this study was to determine the type of NMV-associated feedback that induced the most intense and longest-lasting egocentric post-effects. Eighty-seven healthy individuals were randomly assigned to four intervention groups: "neck muscle vibration, blindfolded" (NMV), "neck muscle vibration with vision" (NMV + V), "neck muscle vibration and visual finger-pointing" (NMV + P), and "visual finger-pointing" (P). An eyes-closed finger-pointing subjective straight-ahead (SSA) test was carried out before the intervention, immediately afterwards, and 30 min afterwards. The results showed that only the NMV + P intervention induced a lasting leftward bias of SSA. In addition, the deviation reported in this intervention group differed significantly from those observed in the other interventions. The combination of visuo-haptic feedback and neck-somatosensory stimulation may enable a full, lasting intermodal recalibration, which could be potentiated by the attention level engaged during voluntary pointing. These outcomes highlighted that the NMV technique could easily integrate into routine occupational therapy sessions for treating various aspects of neglect disorders.

How do children aged 6 to 11 stabilize themselves on an unstable sitting device? The progressive development of axial segment control.

Postural control continues to develop during middle childhood as shown by the decrease in body sway in stance between the ages of 5 and 11. Although head and trunk control is crucial for balance control during both static and dynamic activities, evaluating its specific development and its contribution to overall postural control is methodologically challenging. Here, we used an unstable sitting device adapted to ensure that only the axial segments could control the balance of the device and thus the balance of the upper body. This study aimed to assess the development of the postural stabilization of axial body segments during middle childhood. Thirty-six children (in three age groups: 6-7yo, 8-9yo, and 10-11yo) and 11 adults sat on the unstable sitting device and had to stabilize their axial segments under several conditions: a moderate vs. high level of balance challenge, and eyes open vs. eyes closed. Upper-body postural sway (area, mean velocity and root mean square (RMS) of the center of pressure (CoP) displacement) decreased progressively with age (6-7yo > 8-9yo > 10-11yo > adults), and this effect was accentuated when the balance challenge was high (for CoP area) or in the "eyes closed" condition (for CoP area and RMS). The stabilization strategies were assessed by anchoring indexes computed from three-dimensional kinematics. A progressive shift was showed, from an "en bloc" pattern at 6-7 years of age toward a more articulated (i.e. adult-like) pattern at 10-11. A head-on-space stabilization strategy first emerged at the age of 8-9. Middle childhood is an important period for the development of axial segment stabilization, which continues to mature until adulthood. This development might be related to the introduction and progressive mastery of feedforward sensorimotor processes and might contribute strongly to the development of overall postural control.

Lasting improvements in left spatial neglect following a protocol combining neck-muscle vibration and voluntary arm movements: a case-study.

PURPOSE: Beyond promising experimental results of sensory passive stimulations in spatial cognition disorders, some questions still remain regarding interests of these stimulations during the daily activities in neglect. The aim of this case-study was to evaluate the effects of a protocol combining left neck-muscle vibration with daily simple movements, like arm pointing movements, on perceptivo-locomotor deficits in a left spatial neglect patient. MATERIALS AND METHODS: Two neuropsychological tests, one subjective straight-ahead pointing (SSA) test and one wheelchair navigation test were carried out before the combination protocol, immediately after, 1 h later, and 24 h later. RESULTS: The results showed a reduction of neglect spatial bias following the protocol lasted at least 24 h in all the tests (except for the SSA test due to the unavailability of the pointing device). CONCLUSIONS: The range of improvements in the symptoms of spatial neglect suggests that this therapeutic intervention based on the combining neck-muscle vibration to voluntary arm movements could be a useful treatment for this condition. One of future investigation axes should be the development of a vibratory tool in order to facilitate the combining this proprioceptive stimulation to daily activities. Implications for rehabilitation Spatial neglect is a perplexing neuropsychological syndrome, affecting different domains of spatial cognition and impacting also the functional domain. The treatments based on neck-muscle vibration are simple to use, non-invasive and requires none active participation of patient. A therapeutic intervention based on the combining left neck-muscle vibration and voluntary arm movements in a left-spatial-neglect show a lasting reduction of symptoms especially in daily activities. The combination of treatments based on the Bottom-Up approach opens innovative perspectives in rehabilitation.

Mobility may impact attention abilities in healthy term or prematurely born children at 7-years of age: protocol for an intervention controlled trial.

BACKGROUND: Seven years of age is a milestone for learning basic knowledge that is strongly related to attention abilities such as Alerting, Orienting, and Inhibition function, allowing for appropriate adaptation to primary school. These attention abilities are also influenced by gestational age at birth in a complex manner, indicating an area of weakness in prematurely born children. Furthermore, recent studies suggest that allowing children to have freedom of movement during learning may improve their attention level and school performance. The purpose of the present study is to determine the influence of mobility on the attentional components that may impact learning abilities in children aged 7-years who were born at term and prematurely. METHODS: This prospective, randomized, controlled trial will focus on psychometric testing of attentional abilities assessed with the Attention Network Test for Child (Child ANT) and involves a mixed measurement design. Forty-eight children aged 7-years, half of whom were premature at birth and in their expected grade without learning difficulties will be included after parental consent. They will be equipped with a head-mounted display in which the Child ANT will be presented. The association of different flankers and pre-cues will allow the measurement of the development level of Alerting, Orienting, and Inhibition function. The task will be composed of one experimental block of trials randomly performed per posture: seated, standing, or free. DISCUSSION: This study will assess the contribution of mobility in specific attentional contexts that are usually present during fundamental learning in children. New pedagogical formats of teaching could consider these findings, and new pedagogical tools enabling free spontaneous child mobility might be designed. Moreover, a small percentage of children integrating into the educational system are born prematurely. These children, often considered immature and hyperactive, could benefit from educational innovations that enhance their attention abilities, thereby improving their adaptation to primary school. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov ( NCT03125447 ).

Perception of body movement when real and simulated displacements are combined.

Muscle-tendon vibration has often been used to study the contribution of proprioception to kinesthesia and postural control. This technique is known to simulate the lengthening of the vibrated muscle and, in the presence of balance constraints, evoke compensatory postural responses. The objective of the present study was to clarify the consequences of this stimulation on the dynamic features of whole-body movement perception in upright stance and in the absence of balance constraints. Eleven participants were restrained in a dark room on a motorized backboard that was able to tilt the upright body around the ankle joints. The participants were passively tilted backwards or forwards with a maximum amplitude of four degrees and at very low acceleration (thus preventing the semicircular canals from contributing to movement perception). In half the trials, the body displacement was combined with continuous vibration of the Achilles tendons, which simulates a forward tilt. Participants used a joystick to report when and in which direction they perceived their own whole-body movement. Our results showed that during backward whole-body displacement, the movement detection threshold (i.e. the minimum angular velocity required to accurately perceive passive displacement) was higher in the presence of vibration, whereas the accuracy rate (i.e. the proportion of the overall trial duration during which the movement was correctly indicated) was lower. Conversely, the accuracy rate for forward displacements was higher in the presence of vibration. In the absence of vibration, forward movement was detected earlier than backward movement. The simulated whole-body displacement evoked by Achilles tendon vibration was therefore able to either enhance or disrupt the perception of real, slow, whole-body tilt movements, depending on the congruence between the direction of real and simulated displacements.

Discussion about Visual Dependence in Balance Control: European Society for Clinical Evaluation of Balance Disorders.

The executive committee of the European Society for the clinical evaluation of balance disorders meets annually to address equilibrium problems that are not well understood. This is a review paper on discussions in the latest meeting we held. MATERIALS AND METHODS: Seeing patients with vestibular disorders who end up depending on visual information as part of their compensation process is a common clinical occurrence. However, this "visual dependence" can generate symptoms, which include nausea, sensations of imbalance, and anxiety. It is unclear how this develops, as symptoms can be widely variable from patient to patient. There are several triggering factors to this symptom set, and quantifying it in a given patient is extremely difficult Results: The committee agreed that the presence of this symptom set can be suggestive of vestibular pathology, but the pathology does not have to be present. As a result, there is no correlation between symptom severity and test results. CONCLUSION: Visual dependence can often be present in a patient, although little, if any, measurable pathology is present. It is important to emphasize that although we cannot accurately measure this with either standardized testing or pertinent questionnaires, "hypersensitive" patients have a genuine disease and their symptoms are not of psychiatric origin.

Visuo-oculomotor skills related to the visual demands of sporting environments.

The aim of this study was to assess the visuo-oculomotor skills of gaze orientation in selected sport activities relative to visual demands of the sporting environment. Both temporal and spatial demands of the sporting environment were investigated: The latency and accuracy of horizontal saccades and the gain of the horizontal smooth pursuit of the sporting environment were investigated in 16 fencers, 19 tennis players, 12 gymnasts, 9 swimmers and 18 sedentary participants. For the saccade test, two sequences were tested: In the fixed sequence, participants knew in advance the time interval between each target, as well as the direction and the amplitude of its reappearance; in the Freyss sequence however, the spatial changes of the target (direction and amplitude) were known in advance by participants but the time interval between each target was unknown. For the smooth-pursuit test, participants were instructed to smoothly track a target moving in a predictable sinusoidal, horizontal way without corrective ocular saccades, nor via anticipation or head movements. The results showed no significant differences between specificities of selected sporting activities via the saccade latency (although shorter than in non-athletes), contrary to saccade accuracy and the gain of smooth pursuit. Higher saccade accuracy was observed overall in fencers compared to non-athletes and all other sportsmen with the exception of tennis players. In the smooth-pursuit task, only tennis players presented a significantly higher gain compared to non-athletes and gymnasts. These sport-specific characteristics of the visuo-oculomotor skills are discussed with regard to the different cognitive skills such as attentional allocation and cue utilization ability as well as with regard to the difference in motor preparation.

Does calculating impair postural stabilization allowed by visual cues?

In many daily situations, balance control is associated with a cognitive activity such as reading or a simple calculation. The objective of this study was to investigate the relationship between these two specific human activities, especially the influence of visual cues and support surface stability on body sway during a calculation task. A Sensory Organization Test, which can disrupt or suppress sensory inputs, was performed on 71 healthy young adults. The evaluations were performed both with and without mental arithmetic tasks which consisted of backward counting by three or thirteen. Our results showed that the addition of a calculation task induced an increase in body sway only when visual cues were available. They also showed the same instability effect of the support surface on the amount of body sway no matter what the associated cognitive task was. Moreover, no difference in body sway was observed between the two calculation tasks no matter what the visual context and/or the stability of the support surface were. We suggest that focusing on fulfilling the requirements of the mental calculation challenge may be responsible for the increase in body sway. This increase may be related to the use of oculomotor activity as unintentional attempts to increase arousal by self-generated body movement. Thus, this activity facilitates information processing rather than minimizing unbalance by a visual anchor point.

Influence of head orientation on visually and memory-guided arm movements.

In the absence of visual supervision, tilting the head sideways gives rise to deviations in spatially defined arm movements. The purpose of this study was to determine whether these deviations are restricted to situations with impoverished visual information. Two experiments were conducted in which participants were positioned supine and reproduced with their unseen index finger a 2 dimensional figure either under visual supervision or from memory (eyes closed). In the former condition, the figure remained visible (using a mirror). In the latter condition, the figure was first observed and then reproduced from memory. Participants' head was either aligned with the trunk or tilted 30° towards the left or right shoulder. In experiment 1, participants observed first the figure with the head straight and then reproduced it with the head either aligned or tilted sideways. In Experiment 2, participants observed the figure with the head in the position in which the figure was later reproduced. Results of Experiment 1 and 2 showed deviations of the motor reproduction in the direction opposite to the head in both the memory and visually-guided conditions. However, the deviations decreased significantly under visual supervision when the head was tilted left. In Experiment 1, the perceptual visual bias induced by head tilt was evaluated. Participants were required to align the figure parallel to their median trunk axis. Results revealed that the figure was perceived as parallel with the trunk when it was actually tilted in the direction of the head. Perceptual and motor responses did not correlate. Therefore, as long as visual feedback of the arm is prevented, an internal bias, likely originating from head/trunk representation, alters hand-motor production irrespectively of whether visual feedback of the figure is available or not.

Attenuation of the evoked responses with repeated exposure to proprioceptive disturbances is muscle specific.

In response to repetitive proprioceptive disturbances (vibration) applied to postural muscles, the evoked response has been shown to decrease in amplitude within the first few trials. The present experiment investigated whether this attenuation of the response to vibration stimulation (90Hz, 5s) was muscle specific or would be transferred to the antagonist muscles. Sixteen participants stood upright with eyes closed. One half of the participants practiced 15 tibialis vibrations followed by 15 calf vibrations (TIB-CALF order), while the other half practiced the opposite order (CALF-TIB order). Antero-posterior trunk displacements were measured at the level of C7 and centre of foot pressure (COP). EMG activity of the tibialis anterior (TA) and gastrocnemius lateralis (GL) was also measured. Results showed that evoked postural responses as well as EMG activity decreased with practice when vibration was applied to either calf or tibialis muscles. However, such attenuation of the response appeared muscle specific since it did not generalise when the same vibration stimulus was later applied onto the antagonist muscles.

Postural challenge and adaptation to vibration-induced disturbances.

The described experiment investigated whether adaptation to successive Achilles tendon vibration depends on the postural challenge. In phase 1, thirty-six participants were divided into three groups, each with a different postural challenge. After being blindfolded, participants received 15 trials of Achilles tendon vibration (10 s-90 Hz) while standing upright in either a free-standing condition (FS group), a light finger touch condition (LFT group), or a restrained-standing condition (RS group) in which a dorsal stand prevented body displacement. In phase 2, all participants were freely standing and received 15 additional trials of vibration. Antero-posterior trunk tilt was measured at the level of the trunk (C7). Although there were limited postural readjustments in LFT, adaptation was observed in phase 1 in both FS and LFT groups. In phase 2, the evoked postural displacement was greater in the RS group than in the other two groups. We concluded that although the absence of any postural challenge concomitant to the sensory stimulation prevented adaptation to occur, a minimal challenge was sufficient.

Influence of expectation on postural disturbance evoked by proprioceptive stimulation.

Recent experiments have shown that the vestibular channel of balance control differs fundamentally from the visual channel. Whereas the response to a visual perturbation can be suppressed if the subject has awareness that an upcoming disturbance is likely to be caused by an external agent rather than by self-motion, a similar assumption cannot be made concerning the vestibular system. The present experiment investigated whether postural responses evoked by a proprioceptive perturbation (vibration of the Achilles' tendon at 90 Hz for 2.2 s) are either automatic and immune to expectation (similarly to vestibular responses) or cognitively penetrable (similarly to visual responses). Subjects (n = 12) stood on a force platform while stimuli were delivered either by the subject himself (self-triggered condition) or by the experimenter. For the latter condition, the stimulus was delivered either without warning (unpredictable condition) or at a fixed interval (500 ms) following an auditory cue (precue condition). Results showed that the backward CoP displacement induced by vibration was delayed by approximately 500 ms in the expected and self-triggered conditions compared to the unexpected condition. However, once initiated, the velocity of the backward displacement was higher in the self-triggered condition as compared to the unexpected condition. After a period of 2.2 s of vibration, the amplitude of this backward CoP displacement was similar in the three experimental conditions. Therefore, although expectation appears to delay the upcoming of the main backward body sway, it does not appear to be able to weight the impact of the proprioceptive stimulation. This suggested that afferents provided by the different sensory channels involved in postural control are not similarly susceptible to high level processes such as expectation.