Sensorimotor Conditions Research Articles

Intensive seated robotic training of the ankle in patients with chronic stroke differentially improves gait.

Robotic driven treatment plans targeting isolated joints of the upper limb have improved the sensorimotor condition of patients with stroke. Similar intensive efforts to allay lower limb gait impairment have not been so successful. In patients with stroke, targeted robot assisted training of the ankle joint, in a seated position, has demonstrated significant alterations in ankle stiffness and foot-ankle orientation at foot strike which may provide a new treatment option for gait impairment. To determine if isolated robot-assisted training of the ankle joint improves chronic hemiparetic gait in patients with stroke who are categorized according to baseline gait impairment. Patients with chronic stroke (>6mo) and hemiparetic gait (N = 29) received 18 sessions of isolated robot-assisted motor training of the ankle (3×/week for 6 weeks). All participants had stable clinical baseline scores across three admission measures, and no participant was receiving simultaneous outpatient rehabilitation. Baseline gait speed determined three impairment groups: high, >0.8 m/s; medium, 0.4-0.8 m/s; low, <0.4 m/s. Outcome measures included the Berg Balance Scale, the 6 Minute Walk Test, and the 10 Meter Walk Test, and were recorded upon admission, discharge, and 3 months following intervention. Three distinct and significant between-group patterns of recovery emerged for gait speed. The within-group analysis showed that the medium and high group exhibited significant improvements in gait speed and endurance upon discharge, that were maintained at 3-months. Gait speed improvements were clinically significant (>0.16 m/s) for the high function group across all gait speed and endurance measures at discharge and at 3 months. The moderate group also exhibited clinically significant improvements at follow-up on the 10 Meter Walk Test, fast pace (0.16 m/sec), and approached clinical significance for the 10 Meter Walk comfortable pace (0.12 m/sec). The low group had small but significant improvements, at discharge on two of the three gait measures, and these improvements were maintained at 3 months. For balance measures, the low and moderate impairment groups had significant improvements at discharge that were robust on follow-up measure. The high function group demonstrated no significant change in balance. Joint-specific robotic training of the paretic ankle provided the most benefit to individuals with moderate or mild gait speed impairments after stroke. Baseline gait speed function (low, moderate, high) was associated with three distinct recovery profiles. This suggests that severity-specific intervention may be critical to improving efficiency of stroke recovery.

Effects of a Short-Term Conditioning Intervention on Knee Flexor Sensorimotor and Neuromuscular Performance in Men.

Long-term conditioning programs for enhanced sensorimotor performance have been causally linked to reduced risk of serious ligamentous injury. However, the efficacy of brief, short-term conditioning interventions has not been established. To assess the effects of short-term sensorimotor conditioning on the knee flexors. Randomized controlled trial. University research laboratory. 23 males randomly assigned to conditioning (n = 12; age: 20.5 ± 1.8y; height: 1.80 ± 0.05m; body mass: 74.3 ± 6.0kg [mean ± SD]) and no-conditioning control (n = 11; age: 20.6 ± 1.9y; height: 1.79 ± 0.05m; body mass: 73.6 ± 6.3kg) groups. Sensorimotor conditioning of the nondominant leg (4 sessions/wk; 3wk). Sensorimotor (blind force and limb-position-replication errors) and neuromuscular (peak force, electromechanical delay [volitional and magnetically evoked]) performance of the knee flexors of both legs were assessed. The contralateral limb and an antecedent period of no conditioning were controls. The conditioned leg showed decreased force error to 3.8% (3.8 ± 6.9% vs6.3 ± 3.7% [mean ± SD], post- vspreconditioning, respectively; F1,21 = 5.4; P = .04) and a trend towarddecreased positional error to 2.0% (2.0 ± 6.9% vs4.7 ± 7.7%, post- vspreconditioning; F1,21 = 2.7; P = .06). Performances were not altered in the control conditions. Modest improvements were noted for volitional electromechanical delay following conditioning (39.8 ± 4.3ms vs42.3 ± 5.2ms [F1,21 = 7.2; P = .01]), but peak force (overall, 202 ± 78N) and magnetically evoked electromechanical delay (24.7 ± 4.2ms) were not influenced. Short-term conditioning offered improved sensorimotor performance and positively affected neuromuscular determinants of knee flexor performance in men.

Restless Legs Syndrome: Would You Like That with Movements or Without?

The restless legs syndrome (RLS) is a common sensorimotor condition that often results in discomfort and sleep disturbance. Diagnosis of RLS is entirely clinical and based upon a patient’s description of subjective symptoms, and thus when considering RLS diagnosis non-specificity is a real problem. RLS is associated with periodic limb movements during sleep (PLMS) in up to 90% of RLS sufferers; however, their presence is neither sufficient nor necessary for the diagnosis of RLS. The disease RLS and the motor phenomenon of PLMS share similarities in various areas, which include pathophysiology, pharmacology, genetics, and epidemiology. The purpose of this opinion piece is to outline the many similarities between RLS and PLMS in order to make an argument for the inclusion of PLMS as a supplementary diagnostic criterion of RLS, termed electro-clinical RLS, which would consist of the current clinical RLS diagnosis plus PLMS. This additional criterion could be used in cases where diagnosis is unclear to increase specificity or in research projects where proper diagnosis is desired at the investigational level.

Impact of Parkinson's disease on proprioceptively based on-line movement control.

Evidence suggests that Parkinson's disease (PD) patients produce large spatial errors when reaching to proprioceptively defined targets. Here, we examined whether these movement inaccuracies result mainly from impaired use of proprioceptive inputs for movement planning mechanisms or from on-line movement guidance. Medicated and non-medicated PD patients and healthy controls performed three-dimensional reaching movements in four sensorimotor conditions that increase proprioceptive processing requirements. We assessed the influence of these sensorimotor conditions on the final accuracy and initial kinematics of the movements. If the patterns of final errors are primarily determined by planning processes before the initiation of the movement, the initial kinematics of reaching movements should show similar trends and predict the pattern of final errors. Medicated and non-medicated PD patients showed a greater mean level of final 3D errors than healthy controls when proprioception was the sole source of information guiding the movement, but this difference reached significance only for medicated PD patients. However, the pattern of initial kinematics and final spatial errors were markedly different both between sensorimotor conditions and between groups. Furthermore, medicated and non-medicated PD patients were less efficient than healthy controls in compensating for their initial spatial errors (hand distance from target location at peak velocity) when aiming at proprioceptively defined compared to visually defined targets. Considered together, the results are consistent with a selective deficit in proprioceptively based movement guidance in PD. Furthermore, dopaminergic medication did not improve proprioceptively guided movements in PD patients, indicating that dopaminergic dysfunction within the basal ganglia is not solely responsible for these deficits.

Direct-effects and after-effects of visuomotor adaptation with one arm on subsequent performance with the other arm.

Adapting to a novel sensorimotor condition is generally thought to result in the formation of an internal representation associated with the novel sensorimotor transform. While the presence of after-effects following sensorimotor adaptation is taken as evidence that such an internal representation was developed as a result of adaptation, it remains unclear whether the absence of after-effects following sensorimotor adaptation indicates that no internal representation was developed. In the present study, we examined this question by having individuals adapt to a 30° visual rotation with one arm first and testing 1) how the initial adaptation would influence subsequent performance with the other arm under the same visual condition (called direct-effects) or under a normal visual condition (called after-effects); or 2) how the initial adaptation that occurred at one workspace location would influence subsequent performance at another location with the same arm under the same or a normal visual condition. Results indicated that initial adaptation with one arm significantly influenced subsequent performance with the other in terms of direct- but not after-effects and that initial adaptation at one workspace location significantly influenced subsequent performance at a new location with the same arm in terms of both direct- and after-effects, but to different extents. These findings indicate that formation of a neural representation associated with a novel visuomotor transform does not always result in after-effects and suggest that visuomotor adaptation may involve multiple aspects of a neural representation, some of which are effector independent and some of which are effector dependent.

Restoring motor function with bidirectional neural interfaces.

Closed-loop brain-computer interfaces have bidirectional connections that allow activity-dependent stimulation of the brain, spinal cord, or muscles. Such bidirectional brain-computer interfaces (BBCI) have three major applications that can be used to restore lost motor function. First, the brain could learn to incorporate a long-term artificial recurrent connection into normal behavior, exploiting the brain's ability to adapt to consistent sensorimotor conditions. The obvious clinical application for restoring motor function is to use an artificial recurrent connection to bridge a lost biological connection. Second, activity-dependent stimulation can generate synaptic plasticity on the cellular level. The corresponding clinical application is to strengthen weakened neural connections, such as occur in stroke. A third application involves delivery of activity-dependent deep brain stimulation at subcortical reward sites, which can operantly reinforce the activity that generates the stimulation. The BBCI paradigm has numerous specific applications, depending on the source of the signals and the stimulated targets.

Motor Asymmetry in Elite Fencers

ABSTRACTThe authors previously reported that asymmetrical patterns of hand preference are updated and modified by present sensorimotor conditions. They examined whether participation in long-term training in the upper extremity sport fencing might modify arm selection and performance asymmetries. Eight fencers and eight nonfencers performed reaching movements under 3 experimental conditions: (a) nonchoice right, (b) nonchoice left, and (c) choice, either right or left arm as selected by subject. The nonchoice conditions allowed assessment of potential interlimb differences in movement performance, while the choice condition allowed assessment of the frequency and pattern of arm selection across subject groups. Our findings showed that the athlete group showed substantially greater symmetry in the performance and selection measures. These findings suggest that arm selection and performance asymmetries can be altered by intense long-term practice.

Screening for Sleep Disorders

Article AbstractRestless legs syndrome (RLS) is a common sensorimotor condition with symptoms ranging from mild discomfort to severe pain. Patients with RLS are likely to experience sleep disturbances and have a reduced quality of life. Several misconceptions related to its name, symptoms, and prevalence can hinder the correct diagnosis of RLS. Clinicians should use diagnostic criteria and associated symptom features such as sleep disturbance and family history to confirm the diagnosis and rule out other medical and psychiatric conditions. Several validated tools may assist clinicians by providing sample questions to recognize the symptoms and severity of RLS.See the entire activity.

Dissociating effects of movement preparation and spatial attention on visual processing: evidence from event-related potentials.

The present study investigated whether effects of movement preparation and visual spatial attention on visual processing can be dissociated. Movement preparation and visual spatial attention were manipulated orthogonally in a dual-task design. Ten participants covertly prepared unimanual lateral arm movements to one hemifield, while attending to visual stimuli presented either in the same or in the hemifield opposite to the movement goal. Event-related potentials to task-irrelevant visual stimuli were analysed. Both joint and distinct modulations of visual ERPs by visual spatial attention and movement preparation were observed: The latencies of all analysed peaks (P1, N1, P2) were shorter for matching (in terms of direction of attention and movement) versus non-matching sensory-motor conditions. The P1 amplitude, as well, depended on the sensory-motor matching: The P1 was larger for non-matching compared to matching conditions. By contrast, the N1 amplitude showed additive effects of sensory attention and movement preparation: with attention and movement preparation directed towards the visual stimulus the N1 was largest, with both directed opposite to the stimulus the N1 was smallest. P2 amplitudes, instead, were only modulated by sensory attention. The present data show that movement preparation and sensory spatial attention are tightly linked and interrelated, showing joint modulations throughout stimulus processing. At the same time, however, our data argue against the idea of identity of the two systems. Instead, sensory spatial attention and movement preparation seem to be processed at least partially independently, though still exerting a combined influence on visual stimulus processing.

The development of an accelerometer-based measure of human upright static anterior-posterior postural sway under various sensory conditions: Test–retest reliability, scoring and preliminary validity of the Balance Accelerometry Measure (BAM)

Accelerometers are being used to assess postural control in adults, but there is little to support their reliability and validity. To estimate the test-retest reliability of the balance accelerometry measure (BAM) and to describe the known-groups validity of the BAM composite score. Two measures of standing postural sway were taken across six sensory (vision/stance surface) and motor stance (feet together or tandem) positions from eighteen patients with vestibular disorders and 84 healthy subjects. Test-retest reliability for postural sway was estimated across all conditions using intraclass correlation coefficient (ICC). A composite measure of sway standardized to young healthy subjects on eyes open firm surface stance was compared between groups. Test-retest reliability of postural sway was good (ICC ⩾ 0.74) under all sensory conditions except eyes closed/tandem stance, which was slight to poor. Analysis of the receiver operating characteristic curve for composite scores indicated significant accuracy at identification of subjects in the vestibular/balance disorder groups. Composite standard scores equal or greater than 21.1 identified subjects with vestibular disorders with an accuracy of 72% sensitivity and 68% specificity. The BAM displays good-excellent reliability for five of six sensory-motor conditions. The composite score appears to differentiate healthy from subjects with vestibular disorders.

Sensorimotor‐independent prefrontal activity during response inhibition

A network of brain regions involving the ventral inferior frontal gyrus/anterior insula (vIFG/AI), presupplementary motor area (pre-SMA) and basal ganglia has been implicated in stopping impulsive, unwanted responses. However, whether this network plays an equal role in response inhibition under different sensorimotor contexts has not been tested systematically. Here, we conducted an fMRI experiment using the stop signal task, a sensorimotor task requiring occasional withholding of the planned response upon the presentation of a stop signal. We manipulated both the sensory modality of the stop signal (visual versus auditory) and the motor response modality (hand versus eye). Results showed that the vIFG/AI and the preSMA along with the right middle frontal gyrus were commonly activated in response inhibition across the various sensorimotor conditions. Our findings provide direct evidence for a common role of these frontal areas, but not striatal areas in response inhibition independent of the sensorimotor contexts. Nevertheless, these three frontal regions exhibited different activation patterns during successful and unsuccessful stopping. Together with the existing evidence, we suggest that the vIFG/AI is involved in the early stages of stopping such as triggering the stop process while the preSMA may play a role in regulating other cortical and subcortical regions involved in stopping.

Mobile Posturography

Mobility is crucial to maintain a sufficient quality of life. Posturography should be therefore focused on the investigation of daily-life activities ("mobile posturography"). Nowadays, postural control is often estimated by stance tasks on a force plate under different sensorimotor conditions. This technique applies an indirect approximation of the center of body mass and is not related to tasks required for mobility. An alternative approach would be the direct measurement of body sway during daily-life conditions close to the center of body mass. The present study was aimed at investigating normal age-dependent postural control strategies by analyzing the body sway of male and female subjects in daily-life tasks. Furthermore, the results were compared with data of age- and sex-matched vestibular disorders to determine the sensitivity of the "mobile posturography". Prospective study. The patient group included 76 subjects, and the control group comprised a total of 246 healthy volunteers. Trunk sway measures were performed using the Vertiguard-D device. With the device fixed by a belt at the hip (center of body mass), the subjects had to undergo 14 daily-life tasks under different sensorimotor conditions. Ankle sway was determined during the sensory organization test (SOT) on the BalanceMaster force plate in all patients by estimating the center of body mass from center of pressure changes within the plantar area. A nonlinear relationship between age and body sway was observed in majority of all the conditions. Furthermore, large sex-related differences in body sway were observed.The sensitivity of the mobile posturography was higher than determined during the SOT-force plate measurements or reported in literature before for state-of-the-art platform posturography. The present results indicate that the method introduced here can quantify postural deficits in a broad range and in an inhomogenous sample of patients.

The situated HKB model: how sensorimotor spatial coupling can alter oscillatory brain dynamics

Despite the increase of both dynamic and embodied/situated approaches in cognitive science, there is still little research on how coordination dynamics under a closed sensorimotor loop might induce qualitatively different patterns of neural oscillations compared to those found in isolated systems. We take as a departure point the Haken-Kelso-Bunz (HKB) model, a generic model for dynamic coordination between two oscillatory components, which has proven useful for a vast range of applications in cognitive science and whose dynamical properties are well understood. In order to explore the properties of this model under closed sensorimotor conditions we present what we call the situated HKB model: a robotic model that performs a gradient climbing task and whose “brain” is modeled by the HKB equation. We solve the differential equations that define the agent-environment coupling for increasing values of the agent's sensitivity (sensor gain), finding different behavioral strategies. These results are compared with two different models: a decoupled HKB with no sensory input and a passively-coupled HKB that is also decoupled but receives a structured input generated by a situated agent. We can precisely quantify and qualitatively describe how the properties of the system, when studied in coupled conditions, radically change in a manner that cannot be deduced from the decoupled HKB models alone. We also present the notion of neurodynamic signature as the dynamic pattern that correlates with a specific behavior and we show how only a situated agent can display this signature compared to an agent that simply receives the exact same sensory input. To our knowledge, this is the first analytical solution of the HKB equation in a sensorimotor loop and qualitative and quantitative analytic comparison of spatially coupled vs. decoupled oscillatory controllers. Finally, we discuss the limitations and possible generalization of our model to contemporary neuroscience and philosophy of mind.

Eye-Hand Synergy and Intermittent Behaviors during Target-Directed Tracking with Visual and Non-visual Information

Visual feedback and non-visual information play different roles in tracking of an external target. This study explored the respective roles of the visual and non-visual information in eleven healthy volunteers who coupled the manual cursor to a rhythmically moving target of 0.5 Hz under three sensorimotor conditions: eye-alone tracking (EA), eye-hand tracking with visual feedback of manual outputs (EH tracking), and the same tracking without such feedback (EHM tracking). Tracking error, kinematic variables, and movement intermittency (saccade and speed pulse) were contrasted among tracking conditions. The results showed that EHM tracking exhibited larger pursuit gain, less tracking error, and less movement intermittency for the ocular plant than EA tracking. With the vision of manual cursor, EH tracking achieved superior tracking congruency of the ocular and manual effectors with smaller movement intermittency than EHM tracking, except that the rate precision of manual action was similar for both types of tracking. The present study demonstrated that visibility of manual consequences altered mutual relationships between movement intermittency and tracking error. The speed pulse metrics of manual output were linked to ocular tracking error, and saccade events were time-locked to the positional error of manual tracking during EH tracking. In conclusion, peripheral non-visual information is critical to smooth pursuit characteristics and rate control of rhythmic manual tracking. Visual information adds to eye-hand synchrony, underlying improved amplitude control and elaborate error interpretation during oculo-manual tracking.

Gait adaptability training is affected by visual dependency

As part of a larger gait adaptability training study, we designed a program that presented combinations of visual flow and support-surface manipulations to investigate the response of healthy adults to walking on a treadmill in novel discordant sensorimotor conditions. A visual dependence score was determined for each subject, and this score was used to explore how visual dependency was linked to locomotor performance (1) during three training sessions and (2) in a new discordant environment presented at the conclusion of training. Performance measures included reaction time (RT), stride frequency (SF), and heart rate (HR), which respectively served as indicators of cognitive load, postural stability, and anxiety. We hypothesized that training would affect performance measures differently for highly visually dependent individuals than for their less visually dependent counterparts. A seemingly unrelated estimation analysis of RT, SF, and HR revealed a significant omnibus interaction of visual dependency by session (p < 0.001), suggesting that the magnitude of differences in these measures across training day 1 (TD1), training day 3 (TD3), and exposure to a novel test is dependent on subjects' levels of visual dependency. The RT result, in particular, suggested that highly visually dependent subjects successfully trained to one set of sensory discordant conditions but were unable to apply their adapted skills when introduced to a new sensory discordant environment. This finding augments rationale for developing customized gait training programs that are tailored to an individual. It highlights one factor--personal level of visual dependency--to consider when designing training conditions for a subject or patient. Finally, the link between visual dependency and locomotor performance may offer predictive insight regarding which subjects in a normal population will require more training when preparing for specific novel locomotor conditions.

216 GAIT TRAINING IMPROVES PERFORMANCE IN HEALTHY ADULTS EXPOSED TO NOVEL DISCORDANT CONDITIONS

After they return to Earth, astronauts experience sensorimotor disturbances that disrupt their ability to walk. We have previously shown that training with a variety of sensorimotor adaptive challenges enhances the capability of adapting to novel sensorimotor conditions. We are currently developing a sensorimotor adaptability (SA) training program designed to facilitate recovery of function after gravitational transitions. The purpose of this study was to determine whether trained subjects could transfer learned skills from one discordant visuo-proprioceptive environment to another. During three sessions, subjects walked at 2.5 km/h on a treadmill mounted on a motion base platform. Ten subjects trained with a combination of lateral treadmill translation and superimposed sinusoidal lateral optic flow that was presented on a large screen positioned in front of them. Ten controls completed the same training schedule while viewing only the forward optic flow with no visual or physical oscillation. Twenty minutes after the final training session, all subjects completed a 2-minute trial with a novel combination of visual and treadmill roll perturbations not previously experienced during the training (Transfer Test). Compared to the untrained group, participants who received SA training showed faster reaction times and, based on a composite score derived from stride frequency, heart rate, and reaction time, an overall enhanced performance. Our results showed that an SA training program can improve overall walking performance when subjects are exposed to novel incongruent sensory environments. This training has application for both enhancing adaptive responses in astronauts and reducing fall and injury risk in the elderly.

154 SENSORY BIAS PREDICTS POSTURAL STABILITY, ANXIETY, AND COGNITIVE PERFORMANCE IN HEALTHY ADULTS WALKING IN NOVEL DISCORDANT CONDITIONS

We designed a gait training study that presented combinations of visual flow and support surface manipulations to investigate the response of healthy adults to novel discordant sensorimotor conditions. We aimed to determine whether a relationship existed between subjects visual dependence and their scores on a collective measure of anxiety, cognition, and postural stability in a new discordant environment presented at the conclusion of training (Transfer Test). A treadmill was mounted to a motion base platform positioned 2 m behind a large visual screen. Training consisted of three walking sessions, each within a week of the previous visit, that presented four 5-minute exposures to various combinations of support surface and visual scene manipulations, all lateral sinusoids. The conditions were scene translation only, support surface translation only, simultaneous scene and support surface translations in-phase, and simultaneous scene and support surface translations 180 out-of-phase. During the Transfer Test, the trained participants received a 2-minute novel exposure. A visual sinusoidal roll perturbation, with twice the original flow rate, was superimposed on a sinusoidal support surface roll perturbation that was 90 out of phase with the scene. A high correlation existed between normalized torso translation, measured in the scene-only condition at the first visit, and a combined measure of normalized heart rate, stride frequency, and reaction time at the transfer test. Results suggest that visually dependent participants experience decreased postural stability, increased anxiety, and increased reaction times compared to their less visually dependent counterparts when negotiating novel discordant conditions.

Restless Legs Syndrome Is Associated with Cardiovascular Disease

Restless legs syndrome (RLS) is a common (5%–10% of the population) sensorimotor condition that is diagnosed by evaluating patient history. People with

Helping Three Persons with Multiple Disabilities Acquire Independent Dressing through Assistive Technology

Enabling persons with intellectual or multiple disabilities to carry out personal care tasks (such as washing and dressing) independent of guidance from parents or staff members and without prolonged interruptions is a relevant educational objective (King-Sears & Carpenter, 2005; Lancioni, O'Reilly, Campodonico, & Mantini, 2001; Sewell, Collins, Hemmeter, & Schuster, 1998). Achieving such an objective is often difficult, particularly with persons whose disabilities also include visual impairments (Lancioni et al., 2006), and staff or parental guidance may continue to be needed (King-Sears & Carpenter, 2005). This guidance can be time consuming for staff members or parents and negative for the social image of individuals because it emphasizes their dependence on others (Lancioni, O'Reilly, & Campodonico, 2002). Attempts were recently made to curb the problem of dependency in personal care tasks with the use of assistive technology, which ensured a combination of verbal prompting and preferred stimuli that were automatically delivered on positive performance (see Lancioni et al., 2002, 2006). Three participants were involved in the intervention programs described in these studies, and they all learned to dress themselves. Although these results are encouraging, two aspects of the technology that was used in the interventions raise some questions. First, prompts were delivered at preset intervals, rather than upon the failure to respond of participants. The latter condition would appear preferable in terms of effectiveness and respect for the dignity of participants (Lancioni, O'Reilly, Seedhouse, Furniss, & Cunha, 2000). Second, the prompts and reinforcing stimuli were all auditory. The possibility of using various types of prompts and reinforcing events would be essential for the generalizability of the approach. The goal of the study presented here was to help three new participants with multiple disabilities acquire independent dressing through an upgraded version of the technology. This technology provided prompts only for the failure to respond and included auditory, visual, and vibratory stimuli as reinforcing events or prompts. METHOD Participants The participants, Sylvie, Floyd, and Alan (all names are pseudonyms), were 37, 27, and 29 years old, respectively. They had encephalopathy with a level of functioning estimated to be in the profound range of intellectual disability. Their age equivalents for their daily living skills were about 3 years or younger on the Vineland Adaptive Behavior Scales-Interview Edition (Sparrow, Balla, & Cicchetti, 1984). Sylvie was deaf and had minimal residual vision that allowed her to enjoy light displays and find fairly large objects within about 1 meter (about 39 inches) in front of her and at the center of her visual field. Floyd was totally blind and had typical hearing. Alan was totally blind and deaf and, contrary to the other participants, nonambulatory. These differences in sensory-motor conditions (representative of common variations among individuals with multiple disabilities) allowed for adaptations and a broader evaluation of the assistive technology used in the intervention presented here. All three participants were considered capable of performing the steps of the dressing task, even though Alan needed some physical support to complete the responses of putting on his underpants and pants because of his physical condition. In spite of their general abilities, the three participants still tended to have breaks in performance that required interventions by staff members. Approval for this research was granted by the Scientific and Ethics Committee of the Lega F. D'Oro, Osimo, Italy. The participants were not capable of signing an informed consent form, so their parents did it for them in accordance with Italian law. Setting, dressing task, recording, and reliability The study was carried out in the participants' bedrooms by research assistants who were familiar with the topic of personal care tasks and the delicate issue of respect for the participants' dignity. …

Stance performance under different sensorimotor conditions in patients with post-traumatic otolith disorders

Dynamic posturography with the Equitest system is helpful to screen patients for balance deficits, but diagnostic specificity, for otolith disorders is unknown until now. It was therefore the aim of our present paper to examine patients with a well-defined otolith disorder on the Equitest at different test conditions while simultaneously recording trunk sway by means of the Sway Star system. A total of 22 patients with different types of otolith disorders were included in this study. All test results of the patients were matched with respect to age and gender to controls without history of ENT diseases. The overall sensitivity of the Equitest system in our series was only higher than 50% in 2 conditions. The results of the trunk sway recordings were significantly different between patients with a sacculo-utricular disorder and controls in all test conditions. The results suggest that a disorder of the otolith organs seems to affect especially the trunk sway to a large extent.