Sensory Organization Test Conditions Research Articles

Effect of Kinesiology Tape on Measurements of Balance in Subjects With Chronic Ankle Instability: A Randomized Controlled Trial

ObjectiveTo examine the immediate and prolonged effects (7d) of Kinesiology Tape (KT) on balance in subjects with chronic ankle instability using computerized dynamic posturography (CDP). DesignA 7-day follow-up, single-blind randomized controlled trial. SettingUniversity community. ParticipantsSubjects (N=36) were screened for possible eligibility criteria, and 30 successfully completed the study protocol. Of these, 15 were randomly assigned to the experimental group (KT: 5 men, 10 women), and 15 were assigned to the control group (placebo tape: 10 men, 5 women). InterventionsThe experimental group was taped for a lateral ankle sprain with KT. In the control group, a placebo tape was used. Balance was assessed under the following 3 conditions: without taping, immediately after application, and after 7 days of use. Main Outcome MeasuresThe CDP device used in this study was the Smart Equitest version 8.2. CDP analysis was conducted using the Sensory Organization Test (SOT). As primaries outcome measures, the composite SOT score and composite SOT strategy were chosen. The partial score for SOT condition 2 and its strategy were considered as the secondary outcomes measures. ResultsRepeated-measures analysis of variance (ANOVA) demonstrated that there was not a significant interaction between group and time in the composite SOT score (F=.239; P=.73), SOT condition 2 (F=.333; P=.705), and SOT strategy 2 (F=.899; P=.43). Additionally, repeated-measures ANOVA showed a significant effect for time (composite SOT score: F=40.69; P≤.01; SOT condition 2: F=4.61; P=.014; SOT strategy 2: F=.899; P=.413; composite SOT strategy: F=15.14; P≤.01). Specifically, post hoc analysis showed that both groups obtained improvements in composite SOT scores immediately after tape application and 7 days of use. ConclusionsAccording to our results, the SOT scores of both the KT and control groups improved during follow-up. No differences between them were observed during the follow-up in most balance measurements. The observed changes may be related to a subjective increase in confidence after the tape application.

Simulator Adaptation Syndrome (SAS) and the Vestibular System: An Exploratory Study

Driving simulators are increasingly being used for the evaluation and rehabilitation of fitness-to-drive. However, difficulties with Simulator Adaptation Syndrome (SAS) are commonly reported in the literature. In this study, the authors investigated the relationship between SAS and incongruences between vestibular and visual inputs. Fifteen individuals (age = 61±13 years, 9 females) who developed SAS (SAS+) and 10 individuals (age = 58±13 years, 4 females) who did not develop SAS (SAS-) during two recently completed simulator-based driving studies participated in this study. Participants were each administered the six conditions of the Sensory Organization Test (SOT), made to rest for 30 minutes, and then drove four Wii®-based programs. Performance on the six SOT conditions and on the four the Wii®-based driving programs by SAS+ participants were compared to those of the SAS- participants. No participant reported feeling sick during the SOT. Participants in the SAS+ group performed better (p = 0.0053) than those in the SAS- group only on the SOT fifth condition, which required reliance on vestibular input for maintaining balance control. Four participants in the SAS+ versus one in the SAS- group experienced SAS during the Wii®-based driving (chi-square = 4.63, p = .0314). The results of the study suggest that individuals who developed SAS in the driving simulator probably relied more heavily on their vestibular system than individuals who did not develop SAS, and thus performed better when in situations that required significant integration of vestibular input for maintenance of equilibrium. The independent effect of the driving simulator versus the Wii driving game also suggests that specific characteristics of simulator environment immersion also likely played a role in eliciting SAS. Individuals who rely heavily on their vestibular system for balance control may be more prone to developing SAS in virtual environments that provide only minimal vestibular feedback. More studies are needed to better understand SAS and develop more effective strategies to mitigate it.

¿Es posible reducir el tiempo de exploración en los estudios posturográficos?

Introduction and objectivesThe sensory organization test (SOT) is the gold-standard test for the study of postural control with posturographic platforms. Three registers of Conditions 3, 4, 5 and 6 are conducted to find an arithmetic mean of the 3, with the time that this entails. The aim of this study was to determine whether a single record for each SOT condition would give us the same information as the arithmetic mean of the 3 recordings used until now. Materials and methods100 healthy individuals who performed a sensory organisation test in the Smart Balance Master® Neurocom platform. For the statistical analysis we used the Wilcoxon test for nonparametric variables and dependent t-student for paired samples for parametric variables (P<.05). ResultsWhen comparing the scores on the first record with the average of the 3 records, we found statistically significant differences for the 4 conditions (P<0.05). Comparing the first record to the second record also yielded statistically significant differences in the 4 conditions (P<.05). Upon comparing the second record with the third, however, we found differences in only Condition 5, with the significance being borderline (P=.04). Finally, comparing the average of the first and second record with the average of the 3 records, we also found statistically significant differences for the 4 conditions (P<.05). ConclusionUsing only 1 or 2 records from each of the conditions on the SOT does not give us the same information as the arithmetic average of the 3 records used until now.

Postural Control in Response to Altered Sensory Conditions in Persons With Dysvascular and Traumatic Transtibial Amputation

ObjectiveTo compare the postural control of persons with a dysvascular transtibial amputation and traumatic transtibial amputation with able-bodied adults with and without a dysvascular condition in altered sensory testing conditions. DesignCross-sectional study. SettingUniversity balance clinic. ParticipantsThe study participants (N=35) included: participants with a dysvascular transtibial amputation (n=9), participants with a traumatic transtibial amputation (n=9), age-matched able-bodied adults without a dysvascular condition (n=9), and able-bodied adults with a dysvascular condition (n=8). InterventionsSix Sensory Organization Test (SOT) conditions, which included standing with eyes open (condition 1) and closed (condition 2) on a static force platform with visual surround; standing with eyes open on a static force platform with movable visual surround (condition 3); standing with eyes open (condition 4) and closed (condition 5) on a movable force platform with static visual surround; and standing with eyes open on a movable force platform with movable visual surround (condition 6). Main Outcome MeasuresBilateral anteroposterior (AP) and mediolateral (ML) center of pressure variables, namely root mean square distance (RMSD) and mean velocity (mVel), for each of the 6 SOT conditions. ResultsThe dysvascular transtibial amputation group demonstrated a higher AP RMSD (P≤.04) on the sound side than did the able-bodied adults without a dysvascular condition and the able-bodied adults with a dysvascular condition in SOT conditions 1 and 2, respectively. Both the dysvascular transtibial amputation group and the traumatic transtibial amputation group demonstrated a higher AP RMSD (P≤.002) than the able-bodied adults without a dysvascular condition in SOT conditions 3 and 4. The dysvascular transtibial amputation group showed higher AP mVel (P≤.002) on the sound side for SOT conditions 2 and 3, whereas both amputation groups showed higher AP mVel for SOT conditions 1 and 4 than the able-bodied adults with and without a dysvascular condition. ConclusionsPostural control of the dysvascular transtibial amputation group was not different than the traumatic transtibial amputation group in challenging sensory conditions. However, when compared with the groups of able-bodied adults with and without a dysvascular condition, postural strategies distinct with amputation etiology were observed.

Preoperative balance control compensation in patients with a vestibular schwannoma: Does tumor size matter?

ObjectiveThe influence of tumor size on postural control of patients with vestibular schwannoma (VS) remains to be determined. This study aimed to compare the postural performances of VS patients, according to the size of the tumor, with healthy subjects. MethodsThe six conditions (C1–C6) of the sensory organization test (SOT) were carried out in 87 patients, split into four groups according to the Koos classification (stage I–IV), and in 72 aged-matched controls to evaluate postural control. The vestibular reflectivity and compensation were estimated with videonystagmography. ResultsAmong patients, lower C5 and C6 scores were found in stage I and IV patients than in stage II and III patients, whereas vestibular compensation did not impact the tumor size influence on the postural control. The scores were significantly (p<0.001) lower for all the groups of patients than the controls in the vestibular-related SOT conditions (C5–C6). ConclusionsPatients with an unilateral VS displayed altered postural performances compared to the control subjects and tumor size had a bell-like pattern effect on balance control. SignificanceThe tumor size could be seen as a determining factor in the implementation of adaptive mechanisms that lead to the postural compensation and might be dissociated from vestibular compensation.

Postural strategies assessed with inertial sensors in healthy and parkinsonian subjects

The present study introduces a novel instrumented method to characterize postural movement strategies to maintain balance during stance (ankle and hip strategy), by means of inertial sensors, positioned on the legs and on the trunk.We evaluated postural strategies in subjects with 2 types of Parkinsonism: idiopathic Parkinson's disease (PD) and Progressive Supranuclear Palsy (PSP), and in age-matched control subjects standing under perturbed conditions implemented by the Sensory Organization Test (SOT). Coordination between the upper and lower segments of the body during postural sway was measured using a covariance index over time, by a sliding-window algorithm. Afterwards, a postural strategy index was computed. We also measured the amount of postural sway, as adjunctive information to characterize balance, by the root mean square of the horizontal trunk acceleration signal (RMS). Resultsshowed that control subjects were able to change their postural strategy, whilst PSP and PD subjects persisted in use of an ankle strategy in all conditions. PD subjects had RMS values similar to control subjects even without changing postural strategy appropriately, whereas PSP subjects showed much larger RMS values than controls, resulting in several falls during the most challenging SOT conditions (5 and 6). Results are in accordance with the corresponding clinical literature describing postural behavior in the same kind of subjects.The proposed strategy index, based on the use of inertial sensors on the upper and lower body segments, is a promising and unobtrusive tool to characterize postural strategies performed to attain balance.

Thalamic cholinergic innervation and postural sensory integration function in Parkinson’s disease

The pathophysiology of postural instability in Parkinson's disease remains poorly understood. Normal postural function depends in part on the ability of the postural control system to integrate visual, proprioceptive, and vestibular sensory information. Degeneration of cholinergic neurons in the brainstem pedunculopontine nucleus complex and their thalamic efferent terminals has been implicated in postural control deficits in Parkinson's disease. Our aim was to investigate the relationship of cholinergic terminal loss in thalamus and cortex, and nigrostriatal dopaminergic denervation, on postural sensory integration function in Parkinson's disease. We studied 124 subjects with Parkinson's disease (32 female/92 male; 65.5 ± 7.4 years old; 6.0 ± 4.2 years motor disease duration; modified Hoehn and Yahr mean stage 2.4 ± 0.5) and 25 control subjects (10 female/15 male, 66.8 ± 10.1 years old). All subjects underwent (11)C-dihydrotetrabenazine vesicular monoaminergic transporter type 2 and (11)C-methylpiperidin-4-yl propionate acetylcholinesterase positron emission tomography and the sensory organization test balance platform protocol. Measures of dopaminergic and cholinergic terminal integrity were obtained, i.e. striatal vesicular monoaminergic transporter type 2 binding (distribution volume ratio) and thalamic and cortical acetylcholinesterase hydrolysis rate per minute (k3), respectively. Total centre of pressure excursion (speed), a measure of total sway, and sway variability were determined for individual sensory organization test conditions. Based on normative data, principal component analysis was performed to reduce postural sensory organization functions to robust factors for regression analysis with the dopaminergic and cholinergic terminal data. Factor analysis demonstrated two factors with eigenvalues >2 that explained 52.2% of the variance, mainly reflecting postural sway during sensory organization test Conditions 1-3 and 5, respectively. Regression analysis of the Conditions 1-3 postural sway-related factor [R(2)adj = 0.123, F(5,109) = 4.2, P = 0.002] showed that decreased thalamic cholinergic innervation was associated with increased centre of pressure sway speed (β = -0.389, t = -3.4, P = 0.001) while controlling for covariate effects of cognitive capacity and parkinsonian motor impairments. There was no significant effect of cortical cholinergic terminal deficits or striatal dopaminergic terminal deficits. This effect could only be found for the subjects with Parkinson's disease. We conclude that postural sensory integration function of subjects with Parkinson's disease is modulated by pedunculopontine nucleus-thalamic but not cortical cholinergic innervation. Impaired integrity of pedunculopontine nucleus cholinergic neurons and their thalamic efferents play a role in postural control in patients with Parkinson's disease, possibly by participating in integration of multimodal sensory input information.

Slowed muscle force production and sensory organization deficits contribute to altered postural control strategies in children with developmental coordination disorder

This study aimed to (1) compare the postural control strategies, sensory organization of balance control, and lower limb muscle performance of children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control strategies, sensory organization parameters and knee muscle performance indices among children with DCD. Fifty-eight DCD-affected children and 46 typically developing children participated in the study. Postural control strategies and sensory organization were evaluated with the sensory organization test (SOT). Knee muscle strength and time to produce maximum muscle torque (at 180°/s) were assessed using an isokinetic machine. Analysis of variance was used to compare the outcome variables between groups, and multiple regression analysis was used to examine the relationships between postural control strategies, sensory organization parameters, and isokinetic indices in children with DCD. The DCD group had significantly lower strategy scores (SOT conditions 5 and 6), lower visual and vestibular ratios, and took a longer time to reach peak torque in the knee flexor muscles than the control group (p>0.05). After accounting for age, sex, and body mass index, the vestibular ratio explained 35.8% of the variance in the strategy score of SOT condition 5 (p<0.05). Moreover, the visual ratio, vestibular ratio, and time to peak torque of the knee flexors were all significant predictors (p<0.05) of the strategy score during SOT condition 6, accounting for 14, 19.7, and 19.8% of its variance, respectively. The children with DCD demonstrated deficits in postural control strategy, sensory organization and prolonged duration of muscle force development. Slowed knee muscle force production combined with poor visual and vestibular functioning may result in greater use of hip strategy by children with DCD in sensory challenging environments.

Evaluation of Uncompensated Unilateral Vestibulopathy Using the Modified Clinical Test for Sensory Interaction and Balance

To compare the results of the Modified Clinical Test for Sensory Interaction and Balance (mCTSIB) and the Sensory Organization Test (SOT) of computerized dynamic posturography (CDP) to better understand the role and limitations of the mCTSIB in the diagnosis and rehabilitation of patients with uncompensated unilateral vestibulopathy. Prospective blind study. Tertiary referral center. Ninety-eight patients with uncompensated unilateral vestibulopathy were enrolled. After diagnosis was established through ocular motor studies, head roll and Dix-Hallpike tests, caloric testing, and pure tone audiometry, the mCTSIB and SOT were administered simultaneously. Composite or comprehensive scores and equilibrium scores. When composite or comprehensive scores were used to classify subjects as normal or abnormal, the mCTSIB and SOT showed significant agreement (p > 0.256). SOT condition 2 (eyes closed on a firm surface) showed a greater degree of correlation than did other conditions; the foam-surface or eyes-open conditions yielded poor correlation coefficients. The mCTSIB can be used instead of the SOT in screening to distinguish normality from abnormality in dizzy patients with unilateral vestibulopathy. However, the degree of dizziness assessed by SOT condition was poorly correlated with mCTSIB results, especially in conditions with the eyes open and those using a foam surface.

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

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. Fifteen transtibial amputees (69.5 ± 6.5 years) completed three trials for each of the six SOT conditions. 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.

Assessment of postural control system in autistic patients

EnAbstract Introduction Studies using clinical tests have reported abnormal postural balance in children with autism generally but it was only clinically significant when somatosensory input was disrupted alone or in combination with other sensory challenges. Objective To assess the postural control system in autistic children and correlate their age and Child Autism Rating Scale (CARS) score with their postural control. Methods Computerized dynamic posturography was performed in 20 autistic children with (IQ&gt;70) between the ages of 5 and 15 years and 15 age-matched healthy children. Results There was a statistically significant positive correlation between age in both the study and the control groups and the Sensory Organization Test (SOT) results in all SOT conditions. As regards the degree of autism, this study included 20 autistic children diagnosed by CARS and their CARS values ranged from 30 to 46, with a mean (33.7±3.22). In our study, we found that there was a statistically significant negative correlation between the CARS score in the study group and SOT results in all conditions, except in SOT condition 1. Conclusion The evidence from this study suggests the more general involvement of neural circuitry beyond the neural systems for social behavior, communication, and reasoning, all of which share a high demand on neural integration of information.

A Head Shake Sensory Organization Test to Improve the Sensitivity of the Sensory Organization Test in the Elderly

The head shake sensory organization test (HS-SOT) is an expansion of the sensory organization test (SOT), which evaluates impairment of the patient's ability to apply vestibular input while actively moving the head. HS-SOTs has been proposed to increase the sensitivity of SOTs. The purpose of this study was to investigate the value of HS-SOTs in a healthy population with respect to age and compare the sensitivity of HS-SOTs with that of SOTs in the elderly population. One hundred two (n = 102) healthy subjects were divided into 3 age groups: the young adult group (between 20 and 39 yr), the adult group (between 40 and 59 yr), and the elderly group (between 60 and 79 yr). The subjects underwent SOTs and HS-SOTs. The equilibrium scores of HS-SOTs underwent more significant change than those of SOTs in the elderly group. The equilibrium score ratio SOT2/HS-SOT2 (HS-SOT during SOT condition 2) decreased by 4% more in the elderly group compared with that of the young adult group. The ratio of SOT5/HS-SOT5 decreased by 54% more in the elderly group compared with that of the young adult group. In the elderly, equilibrium scores of HS-SOTs changed more than those of SOTs. In addition, SOT5/HS-SOT5 demonstrated more sensitive changes in the elderly than SOT2/HS-SOT2 did.

Abnormal sensory integration affects balance control in hemiparetic patients within the first year after stroke

OBJECTIVE:Impairments in balance can be a consequence of changes in the motor, sensory, and integrative aspects of motor control. Abnormal sensory reweighting, i.e., the ability to select the most appropriate sensory information to achieve postural stability, may contribute to balance impairment. The Sensory Organization Test is a component of Computerized Dynamic Posturography that evaluates the impact of visual, vestibular, and somatosensory inputs, as well as sensory reweighting, under conditions of sensory conflict. The aim of this study is to compare balance control in hemiparetic patients during the first year post-stroke and in age-matched neurologically normal subjects using the Berg Balance Scale and Computerized Dynamic Posturography.METHODS:We compared the Berg Balance Scale and Sensory Organization Test scores in 21 patients with hemiparesis after first-ever ischemic stroke and in 21 age-matched, neurologically normal subjects. An equilibrium score was defined for each Sensory Organization Test condition.RESULTS:Berg Balance Scale scores were significantly lower in the patients than in the neurologically normal subjects. Equilibrium scores were significantly lower in the patients than in the neurologically normal subjects for those Sensory Organization Test conditions that did not provide appropriate somatosensory information and under conditions of sensory conflict. A history of falls was more frequent in patients with lower equilibrium scores.CONCLUSION:During the first year after a stroke, defective sensory reweighting significantly impacts balance control in hemiparetic patients. These results are important for the planning of effective rehabilitation interventions.

Test-Retest Reliability of the Sensory Organization Test in Older Persons With a Transtibial Amputation

To determine the test-retest reliability of the Sensory Organization Test (SOT) in older persons with a unilateral transtibial amputation. Cross-sectional observational study with repeated measures. A University balance laboratory. Fifteen participants (12 men and 3 women) who had undergone a unilateral transtibial amputation that was performed as a result of either trauma or complications of diabetes or peripheral vascular disease were recruited from a patient database. The mean age of the participants was 69.53 years (SD, 6.60), with 11.94 mean years of prosthetic use. All participants completed 3 trials of the 6 balance testing conditions in the standard SOT protocol with use of the NeuroCom SMART Equitest system on 2 occasions approximately 2 weeks apart. Reliability of the mean equilibrium and strategy scores for the 6 SOT conditions and the overall composite score was evaluated using intraclass correlation coefficients. The test-retest reliability coefficients (intraclass correlation coefficient model 2,1) for the equilibrium scores ranged from 0.67-0.90 for conditions 1 to 4 and 6, indicating fair-to-good reliability. The coefficients obtained for the strategy scores of all the conditions and the composite score showed excellent reliability (intraclass correlation coefficients >0.75). This study suggests that the majority of outcome measurements associated with the SOT protocol on the SMART Equitest provide a reliable measure of dynamic balance performance in older persons with a unilateral transtibial amputation, even in the presence of comorbidities. The equilibrium, strategy, and composite scores obtained from the testing protocol with the exception of condition 5, can be used reliably in clinical practice to monitor for changes in balance with rehabilitation or to monitor the effects of a specific intervention and/or in patients with comorbidities that could potentially affect their balance capacities.

Balance Performance With a Cognitive Task: A Continuation of the Dual-Task Testing Paradigm

To ensure that concussed athletes return to play safely, we need better methods of measuring concussion severity and monitoring concussion resolution. To develop a dual-task model that assesses postural stability and cognitive processing in concussed athletes. Repeated measures study. University laboratory. Twenty healthy, college-aged students (10 men, 10 women; age = 20 ± 1.86 years, height = 173 ± 4.10 cm, mass = 71.83 + 35.77 kg). Participants were tested individually in 2 sessions separated by 2 days. In one session, a balance task and a cognitive task were performed separately. In the other session, the balance and cognitive tasks were performed concurrently. The balance task consisted of 6 conditions of the Sensory Organization Test performed on the NeuroCom Smart Balance Master. The cognitive task consisted of an auditory switch task (3 trials per condition, 60 seconds per trial). For the balance test, scores for each Sensory Organization Test condition; the visual, vestibular, somatosensory, and visual-conflict subscores; and the composite balance score were calculated. For the cognitive task, response time and accuracy were measured. Balance improved during 2 dual-task conditions: fixed support and fixed visual reference (t18 = -2.34, P < .05) and fixed support and sway visual reference (t18 = -2.72, P = .014). Participants' response times were longer (F1,18 = 67.77, P < .001, η2 = 0.79) and choice errors were more numerous under dual-task conditions than under single-task conditions (F1,18 = 5.58, P = .03, η2 = 0.24). However, differences were observed only during category-switch trials. Balance was either maintained or improved under dual-task conditions. Thus, postural control took priority over cognitive processing when the tasks were performed concurrently. Furthermore, dual-task conditions can isolate specific mental processes that may be useful for evaluating concussed individuals.

A comparison of accelerometry and center of pressure measures during computerized dynamic posturography: A measure of balance

Accelerometry (ACC) shows promise as an easily implemented clinical measure of balance. The purpose of the study was to estimate test–retest reliability of ACC measures and determine the relationship between ACC measured at the pelvis and underfoot center of pressure (COP) measures during sensory organization test (SOT) conditions. Eighty-one subjects were recruited from the community with no known orthopedic or vestibular deficits (19–85 years). Subjects completed three consecutive, ninety second trials for each of the six SOT conditions, while wearing the accelerometer. ACC and COP time series were described by calculating the normalized path length, root mean square (RMS), and peak-to-peak values. The test–retest reliability of the three measures within each SOT condition was estimated over three trials using the intraclass correlation coefficient. ACC and COP test–retest reliability were similar, ranging from 0.63 to 0.80 using ACC and 0.42 to 0.81 using COP for the measure of normalized path length. Linear regression between ACC and COP measures showed significant correlation under almost every SOT condition using both single and average measures across trials. The degree of association between COP and ACC was equivalent when using the first trial or the 3-trial average, suggesting that one trial may be sufficient. The use of accelerometry may have value in estimating balance function and minimizing clinical evaluation time.

Balance Performance in Head-Shake Computerized Dynamic Posturography: Aging Effects and Test-Retest Reliability

The ability of the Sensory Organization Test (SOT) to detect subtle balance problems has been challenged. The Head-Shake Sensory Organization Test (HS-SOT) has been developed to improve the delineation of balance performance. The purposes of this study were: (1) to examine age-related differences in balance measured with the HS-SOT and (2) to establish the test-retest reliability of the HS-SOT in younger adults who were healthy and older adults who were healthy. A test-retest design was used in this observational measurement study. Ninety-two younger adults who were healthy (mean age=28.3 years) and 73 older adults who were healthy (mean age=60.3 years) underwent the SOT and the HS-SOT. Seventy-seven of them (56 younger adults, 21 older adults) underwent the same assessments 1 to 2 weeks later. The equilibrium scores in HS-SOT conditions 2 (head movements with eyes closed while standing on a firm surface) and 5 (head movements with eyes closed while standing on a sway-referenced surface) were significantly lower than those in tests without dynamic head movements added (SOT conditions 2 and 5). Older adults attained significantly lower scores in both HS-SOT conditions than their younger peers. The test-retest reliability values, reported as intraclass correlation coefficients (ICC [3,2]), of the HS-SOT scores in conditions 2 and 5 for the younger adults were .85 and .78, respectively; those for the older adults were .64 and .55, respectively. The corresponding minimal detectable change values for the former were 2.7 and 16.2, and those for the latter were 3.6 and 22.7. Only head rotation movements on the horizontal plane were tested. Adding head movements to the SOT increased the separation of younger adults who were healthy and older adults who were healthy. The HS-SOT has good reliability, and the reported minimal detectable change values may facilitate the interpretation of clinical studies in which the HS-SOT is used to assess changes in balance performance in younger and older adults.

Postural Responses to Dynamic Perturbations in Amputee Fallers Versus Nonfallers: A Comparative Study With Able-Bodied Subjects

Vanicek N, Strike S, McNaughton L, Polman R. Postural responses to dynamic perturbations in amputee fallers versus nonfallers: a comparative study with able-bodied subjects. Objectives To quantify postural responses in amputee fallers versus nonfallers by using computerized dynamic posturography. Design All participants completed standard protocols on the Sensory Organization Test (SOT) and Motor Control Test (MCT) of the NeuroCom Equitest. Setting Human performance laboratory in a university in the United Kingdom. Participants Transtibial amputees (n=9) and able-bodied subjects (n=9) (all categorized into fallers and nonfallers according to their falls history in the previous 9mo). Interventions Not applicable. Main Outcome Measures Equilibrium and strategy scores on the SOT. Postural response latency and weight distribution on the MCT. Results Equilibrium scores were highest when somatosensory information was accurate, but there were no differences between the groups. Strategy scores were lower when visual cues and somatosensory information were inaccurate, and the fallers and nonfallers used a combination of ankle and hip strategies to prevent a loss of balance. The amputee nonfallers indicated they had a greater reliance on visual input even when it was inaccurate compared with the amputee fallers, whereas the control fallers used the hip strategy significantly more compared with the control nonfallers (SOT condition 6: 56±22 vs 72±10, P=.01). Weight distribution symmetry showed that the amputee nonfallers bore significantly more weight through their intact limb compared with the amputee fallers during backward and forward translations ( P<.05). Conclusions The SOT and MCT appeared to be population specific and therefore did not reliably identify fallers among transtibial amputees or distinguish between community-dwelling control fallers and nonfallers. Amputee and control fallers can prevent a fall during challenging static and dynamic conditions by adapting their neuromuscular responses. The results from this study have important implications for amputee gait rehabilitation, falls prevention, and treatment programs.

Test Order Effects of Computerized Dynamic Posturography and Calorics

To determine whether there is a test order effect of the caloric subtest of videonystagmography on the Sensory Organization Test (SOT) of computerized dynamic posturography, and to assess the learning effect of multiple posturography test sessions on the SOT score. Scores on the 6 SOT conditions before and after caloric testing were compared for 10 participants age 18-36 years. Four SOT sessions were completed prior to caloric testing to assess the presence of a learning effect and establish precaloric baseline SOT scores. All participants had normal vestibular systems with no history of dizziness or imbalance. Caloric testing had a significant effect on the equilibrium score for only 1 of 6 test conditions. While meeting statistical significance, the actual change in score for this condition was very small. Equilibrium scores improved for the more difficult test conditions between the 1st and 2nd SOT sessions. Results indicate that there are minimal test order effects of calorics on the SOT. Results confirm that a significant improvement in score for more challenging test conditions occurs between SOT Sessions 1 and 2 as a result of learning. Therefore, clinicians must be cautious when using posturography to monitor patient improvement.

Kinematics Analysis of Knee Joint Motion in Closed Chain Movement among Different Sports Events: A Pilot Study

Accelerometry (ACC) shows promise as an easily implemented clinical measure of balance. The purpose of the study was to estimate test–retest reliability of ACC measures and determine the relationship between ACC measured at the pelvis and underfoot center of pressure (COP) measures during sensory organization test (SOT) conditions. Eighty-one subjects were recruited from the community with no known orthopedic or vestibular deficits (19–85 years). Subjects completed three consecutive, ninety second trials for each of the six SOT conditions, while wearing the accelerometer. ACC and COP time series were described by calculating the normalized path length, root mean square (RMS), and peak-to-peak values. The test–retest reliability of the three measures within each SOT condition was estimated over three trials using the intraclass correlation coefficient. ACC and COP test–retest reliability were similar, ranging from 0.63 to 0.80 using ACC and 0.42 to 0.81 using COP for the measure of normalized path length. Linear regression between ACC and COP measures showed significant correlation under almost every SOT condition using both single and average measures across trials. The degree of association between COP and ACC was equivalent when using the first trial or the 3-trial average, suggesting that one trial may be sufficient. The use of accelerometry may have value in estimating balance function and minimizing clinical evaluation time.