Posture Evoked Response Detecting in Normal Lower Limb Muscle and Its Influ-encing Factors / 法医学杂志

Objective To analyze the latency of posture evoked response of normal lower limb muscle in different stimulations and explore its influencing factors. Methods The normal lower limb was induced to produce postural evoked response by the dynamic posturography through two kinds of perturbations, the supporting surface rotation stimulation (Toes-up and Toes-down) and the horizontal perturbation stimulation (Forward and Backward). The latencies of tibialis anterior muscle and gastrocnemius muscle were recorded by surface electromyography acquisition system. The differences of the left and right limb, gen-der and height on the latency of postural evoked response were analyzed. Results (1) Under the Toes-up and Backward perturbation, the latency of tibialis anterior muscle was longer than gastrocnemius muscle;under the Toes-down and Forward perturbation, the latency of gastrocnemius muscle was longer than tib-ialis anterior muscle. (2) The latencies of left limb and right limb had no significant difference. (3) The la-tency in male was longer than that in female. (4) The latency gradually increased with the increase of height. Conclusion In the postural evoked response, different perturbations, gender and height have sig-nificant impacts on the latency of posture evoked response of lower limb muscle. However, the effect of height and gender should be not considered referring to the same individual.

Revisão sobre Posturografia Dinâmica: Uma ferramenta para avaliação do equilíbrio de idosos / Review of Dynamic Posturography: A tool for assessing the balance of elderly

O processo do envelhecimento pode levar a importantes alterações no equilíbrio dos indivíduos, em consequência à degeneração dos sistemas visual, auditivo e proprioceptivo. A avaliação da contribuição desses sistemas para o equilíbrio corporal é de grande importância. Diante disso, o presente estudo busca, através de uma revisão, apresentar um instrumento que pode ser usado para avaliação do equilíbrio postural, bem como quantificar a contribuição de cada sistema para o equilíbrio do idoso...

The aging process can lead to major changes in the individuals balance, due to degeneration of the visual, auditory and proprioceptive systems. Assessing these systems is very importance for body balance contribution. Thus, the present study attempts, through a revision, provide an instrument that can be used to evaluate the postural balance and quantify the contribution of each system to the balance in elderly...

New Proposal of Functional Status of Vestibular System Based on Vestibular Function Tests Findings in Dizzy Patients with Normal Caloric Response / 대한평형의학회지

BACKGROUND AND OBJECTIVES: Vestibular function tests are very useful in diagnosing dizzy patients. Among them, bithermal caloric test is most commonly used test for localizing their permanent vestibular loss. However, it causes much discomfort to the patients with non-physiologic stimuli. In addition, it doesn't represent the present functional status of vestibular system. Therefore, normal caloric result does not accurately correspond to normal vestibular function in dizzy patients. Currently, rotation chair test and dynamic posturography have been introduced adjunctly to assess vestibular function accompanied by bithermal caloric test. It has not been elucidated for their specific role in diverse settings of vestibular disorders. So we planned this study to evaluate clinical usefulness of rotation chair test, videonystagmography and computerized dynamic posturogr-phy in dizzy patients with normal caloric response. MATERIALS AND METHODS: We reviewed clinical records of 46 patients who met their inclusion criteria. They were categorized into five subgroups according to abnormal vestibular function test findings. RESULTS: In each subgroup, we hypothesized its clinical relevance, possible mechanism of dizz-iness and presumed diagnosis. Five categories are as below; visual dependency, imbalance of vestibular tones, chronic peripheral vestibulopathy, abnormality in the vestibulospinal tract and abnormality of oculomotor system. CONCLUSION: We suggest new classification of abnormal vestibular functional status in dizzy patients with normal caloric results. These are comparable according their clinical features and thought to be helpful in managing and counseling each patient.

Does the Kyphotic Change Decrease the Risk of Fall?

OBJECTIVES: Falls are a major problem in the elderly. Age-related degeneration of the human balance system increases the risk of falls. Kyphosis is a common condition of curvature of the upper spine in the elderly and its development occurs through degenerative change. However, relatively little is known about the effect of kyphotic changes on balance in the elderly. The aim of this study is to investigate the influence of kyphosis on the balance strategy through use of the motor control test (MCT) in computerized dynamic posturography. METHODS: Fifty healthy subjects who were not affected by other medical disorders that could affect gait or balance were enrolled in the study. By simulation of kyphotic condition through change of the angles of the line connecting the shoulder to the hip and the ankle axis by approximately 30degrees, the latency and amplitude of the MCT were measured in upright and kyphotic condition. RESULTS: In the kyphotic condition, latency was shortened in backward movement. In forward movement, latency was shortened only in large stimulation. The amplitude in forward movement was decreased in kyphotic condition. However, the change of amplitude was not significant in large intensity backward movement in the same condition. CONCLUSION: Kyphotic condition decreases the latency of MCT, especially in backward movement. These findings imply that kyphotic condition may serve as a protective factor against falls.

The clinical value of dynamic posturography in the peripheral vertigo / 临床耳鼻咽喉头颈外科杂志

Objective:To explore the clinical value of dynamic posturography in the diagnosis of peripheral vertigo. Method:One hundred and sixty peripheral vertigo patients with full clinical documents in vertigo clinic of our hospital from May 2007 to May 2008 were retrospectively analyzed in this study. All the patients firstly underwent the inspection of static and dynamic posturography and then were subjected to caloric test using videonystagmogra-phy. The results were conducted a comparative analysis. Surface of the statokinesigram (SSKG) was selected as assessment parameter of static posturography. The result of sensory organization test (SOT) were selected as assessment parameters of dynamic posturography. The unilateral weakness was selected as assessment parameter of caloric test. Twenty normal subjects were selected as control. Result: Among the 160 cases with peripheral vertigo, results of SOT in dynamic posturography were abnormal in 144 cases, with a sensitivity of 90. 0%; caloric test was abnormal in 110 cases, with a sensitivity of 68. 8%; static posturography was abnormal in 76 cases, with a sensitivity of 47. 5%. There existed a statistically significant difference between dynamic posturography and caloric test or static posturography. There were 40 patients(25. 0%) who had normal caloric test results in which dynamic posturograph findings were abnormal. Among the 20 cases of normal people, results of SOT in dynamic posturography were abnormal in only one case(5. 0%). Conclusion:With its superior sensitivity and specificity, dynamic posturography has been an objective and reliable approach in the diagnosis of peripheral vertigo. It can help to confirm the presence of abnormalities in some peripheral vertigo patients whose caloric results are normal.

The Effect of Knee Osteoarthritis and Unilateral Total Knee Arthroplasty on Balance

OBJECTIVE: To assess the effect of knee osteoarthritis (OA) and unilateral total knee arthroplasty (TKA) on balance. METHOD: Fifteen patients with bilateral knee OA and fifteen patients with unilateral TKA and fifteen healthy adults were assessed by computerized dynamic posturography. The posturography test was performed 3 times at 6 different simulated conditions. We evaluated anteroposterior sway of center of gravity and strategy score of OA group, TKA group and healthy adults group. We compared the equilibrium scores of each group with normal data reported previously. We also compared strategy scores of each group. RESULTS: Patients with bilateral knee OA and unilateral TKA showed lower equilibrium scores than normal one at the condition 4, 5, 6. But patients with unilateral TKA did not show significant equilibrium score difference as compared with bilateral knee OA patients. Patients with bilateral knee OA and unilateral TKA showed significantly lower strategy scores than normal one at the condition 4, 5, 6 (p<0.05). But patients with unilateral TKA did not show significant strategy score difference as compared with bilateral knee OA patients. CONCLUSION: Patients with bilateral knee OA showed deficit of dynamic postural control due to proprioceptive dysfunction. And TKA did not affect proprioceptive change in knee osteoarthritis.

Change of the Balance Function with Aging: Computerized Dynamic Posturography Study

BACKGROUND: The purpose of this study is to evaluate balance functions as one ages using the values of the sensory organization test (SOT) and the motor control test (MCT) of computerized dynamic posturography (CDP) in healthy Korean adults. METHODS: We studied the equilibrium scores of the SOT and weight symmetries, latencies, and adaptation scores of the MCT in 72 healthy Korean adults. Subjects were divided into three age groups, the 30's (young group), 50's (middle-aged group), and 70's (elderly group). RESULTS: In the SOT, the range of mean equilibrium scores was from 69.8 to 94.2 in the 3rd decade group, 62.6 to 93.8 in the 5th decade group, 59.2 to 91.2 in the 7th decade group. In the MCT, during sudden anterior and posterior perturbations, the weight symmetries were 101.1 +/- 7.5 in the 3rd decade group, 103.6 +/- 6.9 in the 5th decade group, and 106.4 +/- 9.4 in the 7th decade group. The mean latencies were 123.6-132.8 msec in the 3rd decade group, 130.5-138.5 msec in the 5th decade group, 132.7-141.8 msec in the 7th decade group. CONCLUSIONS: Almost all measures of balance were significantly worse in the elderly group compared with the young group and some changes of balance were observed in the middle-aged group as well. These significant age-associated declines of balance function suggested the decreased capacity to process sensory inputs in aged persons. This occurs most likely as a result of biomechanical or central processing changes.

Correlation between Berg Balance Scale and Sensory Organization Test of Computerized Dynamic Posturography in Brain Injured Patients

OBJECTIVE: To examine the correlation between Berg balance scale (BBS) which is tool for assessing the clinical balance function and sensory organization test (SOT) of computerized dynamic posturography (CDP) in brain injured patients. METHOD: Thirty patients with brain injury were assessed on the BBS and SOT of CDP. BBS consists of 14 items and each item is graded on a five point ordinal scale (0~4), yielding a total of 56 points. According to its characteristics, each item was divided 3 groups, which were sitting, standing and position change. Six equilibrium scores (EQ) were determined by SOT of CDP (EquiTest System , Version 5.08) under 6 conditions, and somatosensory, visual, vestibular ratios were analyzed by 6 EQ scores. RESULTS: EQ 5 was correlated with reaching forward item (r=0.513), turning 360 degrees item (r=0.537), stool stepping item (r=0.529) of BBS (p<0.01). EQ 6 was correlated with turning 360 degrees item (r=0.498) of BBS (p<0.01). Sum of standing item group scores was correlated with EQ 5 (r=0.478), EQ 6 (r=0.464), and sum of position change item scores was correlated with EQ 5 (r=0.622), EQ 6 (r=0.514) (p<0.01). Vestibular ratio was correlated with BBS total score (r=0.552, p<0.01). CONCLUSION: We concluded that vestibular ratio of SOT was correlated with BBS, especially position change item group. Therefore BBS is a good tool for evaluating vestibular function in brain injured patients.

Motion-stress Effect on the Body Centroid, Such as Head-Shaking and an Alteration of the Body Position in Old Subjects

BACKGROUND: It is well known that many patients with vertigo become vertinous when all alteration o the body position occurs while either head-shaking or after standing up. Posturaphy conducted with those patients when standing still is thus not always successful in detecting abnormal symptoms However. such abnormalities can be easily detected when the patients are subjected to motion-stress, such as head -shaking or alterations of the body position. The effect of such motion-stress on the disturbance of the centroid in normal individuals has yet to he clarified. METHODS: In this study, posturography was conducted normal subjects who were subjected to motion-stress in the manner mentioned above and the results of this test were then compared with the findings of a conventional test. RESULTS: Through this comparison no increase in the unbalance, as a result of the applied motion-stress, was observed for the X distance(XD), Y distance(YD) and Length(LNG). However, a significant increase in the imbalance was found for the XD and LNG itt (lid subjects. CONCLUSION: Therefore, motion-stress, such its head-shaking or alterations of the body position can be helpful in detecting vertiginous symptoms in vertigo patients. But in the elderly patients the merit of above stimuli during the test should be vet clarified

Computerized Dynamic Posturography study of Parkinson's Disease Patients of Old Age

BACKGROUNDS: Postural instability and vertigo arc not uncommon complaint from Parkinson`s disease (PD) patients. But little is known about the underlying cause of the symptoms. METHODS: Thirty-two patients with over 55 year of age, having Parkinson`s disease are studied with using a recently developed computerized dynamic posturography(CDP) and rotating chair testing(ROT) RESULTS: Vestibular dysfunction pat tent is found in 21 patients and improper use of vision was found in 10 patients. Delayed motor latency was noted in 5 patients. Saccadie dysmetria and prolonged saccadic reaction times were common features in all patients. 6 patients(18.8%) had absent responses in cold( 17degrees C) water caloric resting bilaterally and decreased responses in the lower frequencies(0.01~0.16 Hz) by ROT. Their vestibulo-ocular reflex could be suppressed during the ROT with visual fixation. MRI showed the presence of an infarction of the caudal cerebellum in one patient, the pons in another, and narrowed vertebral arteries in two patients. CONCLUSION: Relatively high incidence of vestibular dysfunction is associated with postural instability and increasing severity of symptoms. The main site of dysfunction in postural control is likely to be at a central motor level.

Posturographic Characteristics of Lesion Site in Stroke Patients

OBJECTIVE: To determine the posturographic characteristics of the stroke patients due to various brain lesions. METHOD: Stroke patients capable of standing without assistive devices were included. Patients were divided into three groups according to the lesion distribution: cerebral; brain stem; cerebellar. Quantitative computerized posturographic studies were performed to determine the subject's response to sensory (sensory organization test, SOT) and motor translations (motor control test, MCT). RESULTS: Equilibrium scores of 4th (EQ4), 5th (EQ5) and 6th (EQ6) conditions and visual (VIS) and vestibular (VEST) ratio of SOT were significantly lower in brainstem and cerebellar lesion groups in comparison with normal population. In addition, prolonged latencies for medium and large backward and forward translations were noticed in the brainstem lesion group. However, there was no significant difference between cerebral lesion group and normal population. According to the lesion distribution, cerebellar group showed increased incidence of abnormalities of EQ4 score. Brainstem group showed increased incidence of abnormalities in EQ5, EQ6 score, VEST ratio and prolonged latency for large forward translation. CONCLUSION: We found that posturography revealed characteristic appearances according to the various brain lesions, especially in cerebellum and brainstem stroke patients.

Postural Stability in Patients with Chronic Ankle Sprain

OBJECTIVE: To investigate the deficit of static and dynamic postural control in patients with chronic ankle sprain using dynamic posturography. METHOD: Twenty patients with unilateral recurrent ankle sprain and functional instability were assessed by Samsung medical center ankle injury score and by computerized dynamic posturography (EquiTest system, Neurocom , international, INC; USA). The posturography test was performed 3 times at 6 different simulated conditions such as fixed of force platform/open eyes/fixed of screen (condition 1), fixed/closed/fixed (condition 2), fixed/open/movement (condition 3), sway/open/fixed (condition 4), sway/closed/fixed (condition 5), sway/open/movement (condition 6). We evaluated anteroposterior sway of center of gravity of the patients and calculated equilibrium scores. We compared the equilibrium scores of patient group and normal data reported previously. We also compared the equilibrium scores of two subgroups of the patients according to severity of ankle injury. RESULTS: Patients showed significantly low equilibrium scores than normal one at the condition 4, 5 and 6 (p<0.05). The group B with severe ankle injury revealed low equilibrium scores at the condition 4, 5 and 6. Especially the group B showed statistically significance at condition 5 (p<0.05). CONCLUSION: Patients with chronic ankle sprain showed the deficit of dynamic postural control due to the proprioceptive dysfunction of injured ankle than normal person.

The Effect of Alcohol on Dynamic Posturography / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The acute effect of alcohol is well known. However, although many authors have studied the effect of alcohol on equilibrium and found a deteriorated balancing capacity, objective studies of deteriorated balancing capacity have rarely been reported. The object of this study is to assess the effect of alcohol on vestibular function impairment by dynamic posturography. MAERIALS AND METHODS: Twelve healthy male volunteers aged 23-27 years (mean 25years) were assessed by dynamic posturography 30 min, 60 min and 90 min before and after the ingestion of alcohol. Alcohol levels were measured by blood samples 30, 60 and 90 min before, at and after ingestion. The samples were analyzed for alcohol by chromatography (SIGMA diagnostics). Each condition in SOT and latencies in MCT were used to estimate the effect of alcohol. RESULTS: The obtained results were as follows: 1) The time when serum alcohol concentration reach the maximum was 60 minute (50%). 2) Conditions 4, 5, 6 and composite scores showed statistically significant lower equilibrium scores (p0.05). CONCLUSION: Acute alcohol ingestion influences impairment of vestibular and visual input on equilibrium.

Usefulness of Motor Control Test (MCT) to Evaluate Balance Function in Diabetic Patients with Neuropathy / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: It is important to adequately estimate the functional handicap of the patient with polyneuropathy. Computerized dynamic posturography (CDP) can be utilized in those patients to evaluate balance performance. But, so far, the majority of data are about sensory organization test (SOT) and the efficacy of motor control test (MCT) is not established. We performed this study in an attempt to estimate balance function in diabetic neuropathy patients using MCT, thereby confirm the usefulness of MCT in evaluating balance ability. SUBJECTS AND METHODS: Seventeen diabetic neuropathy patients (DM-NP), 9 non-neuropathy diabetic patients (DM-nonNP), and 22 non-diabetic normal persons as controls (nonDM) were included in this study. Postural responses to horizontal translation were assessed according to the MCT paradigm. The results were compared with the sway energy obtained during toes-up or toes-down perturbation. RESULTS: Latencies of backward translation were prolonged in DM-NP but not in DM-nonNP. Latencies of forward translation were prolonged both in DM-NP and DM-nonNP. No definite correlation could be drawn between the MCT and EMG latencies. DM-NP showed increased sway energy in toes-up and toes-down perturbation. MCT latencies and sway energy in perturbation showed significant correlation. CONCLUSION: MCT proved to be useful in evaluating balance performance in the patients with defective postural response as in diabetic neuropathy.

Evaluation of Compensation in Peripheral Vestibulopathy / 대한이비인후과학회지

The initial severe and disabling symptoms of vestibular dysfunction diminish gradually by a process of compensation. Although the process is complex and not fully understood, knowledge of the extent of compensation makes physicians to identify the causes and to determine treatment choices of the dysfunction. In this report we present 2 common cases of peripheral vestibulopathy that result from different disease processes, and review the physiologic and functional changes as the compensation proceeds that can be evaluated by vestibular function tests including electronystagmography(ENG), rotation chair, and dynamic posturography. These tests are valuable tools in the assessment of the degree of compensation as well as the side and site of lesions in vestibulopathy.

A study of posture in 112 healthy korean population using computerized dynamic posturography

OBJECTIVE: To study normal values of wnwry organimtion test(SOT) and motor control test(MCT) of computerized dynamic posturography(CDP) in the healthy Koreans. BACKGROUND: Balance is made up of three biological functions ; sensory input, motor output, and CNS integration. But, there has been no method for assessing the sensory, motor, and CNS integration function quantitatively. CDP is a tool for assessing the balance function quantitatively under a variety of tasks. METHODS: To assess the balance using CDP, I studied equilibrium score(ES) of SOT and weight symmetry, latency, and adaptation seems of MCT in 112 Korean healthy population. Arbitarily I divided the population into two groups, under 60 years and over 60 years of age. In SOT, I studied the contribution of each sense to maintaining equilibrium when other senses were either absent or provided with inaccurate information. MCT provoked autonomic postural reactions through a series of sudden anterior and posterior support surface translations. In MCT, I studied latencies in sudden translation of fact plate. RESULTS: The study group was 112 Korean healthy population with a mean age of 47 +/- 26 years. In SOT, the range of median equilibrium seems were from 68 to 93 under 60 years group, 58 to 91 over 60 years group. In MCT, during sudden anterior and posterior pertubation, weight symmetries were 101 +/- 24.8 under 60 years group and 104 + 30. 1 over 60 years group. Median latencies were 116 to 141msec under 60 years, 127 to 130msec over 60 down test of MCT the mean adaptation scores were 60 years. 64 to 75 and 48 to 73 over 60 years, respectively. CONCLUSION: This study could be a baseline control data in sensory, motor, and CNS integration function of balance in dizziness patient using CDP.