年龄和视觉对直立静态平衡的影响

为研究年龄和视觉系统对人体立位姿态平衡功能的影响，应用ＳＴ－９３９人体重心平衡仪，对１２７名正常人进行立位姿态平衡功能测试，观察重心移动的外周面积、路径总长和平均速度以及重心在不同圆内的分布图（即姿态图）结果显示：①正常人重心移动的外周面积、路径总长和平均速度随年龄增和而增大；②７０岁组闭睁眼测试面积差值最大。本项研究结论认为２０￣６０岁年龄内姿态平衡功能最佳，６０岁以后出现衰退。在年长者中视觉系     

儿童立位姿态平衡发展过程的研究

目的 研究健康儿童立位姿态平衡功能发展成熟过程以及视觉系统在儿童姿态平衡中的作用.方法 对214名4～15岁儿童按年龄分为12组,采用ST-939人体重心平衡仪,对各组分别行立位姿态平衡功能测试,以20例20岁成年人作为对照组,重点观察睁眼和闭眼两种状态下的重心移动速度(open velocity,OV和closed velocity,CV).结果 OV和CV随年龄增长而呈逐渐下降趋势;8岁以前儿童闭睁眼重心移动速度差值与成年人比较差异有显著统计学意义(P＜0.05).结论 儿童姿态稳定性随年龄增长而逐渐趋于成熟,年幼儿童可能以一种与成年人不同的方式利用视觉系统来维持姿态的稳定性,8岁以后类似于成年人的姿态平衡开始出现.     

静态平衡功能定量分析

目的测试正常人各年龄段之姿势图，并比较正常人与眩晕者姿势图的各参数。方法采用日本Anima公司G5500型静态平衡仪对164名正常人及167名眩晕病人进行重心动摇测试。受试者直立于平衡台上，足底中心与平台之基准点一致，睁闭眼各测60S，计算机绘制人体重心移动的图形，重心移动的外周面积、轨迹长度、XY轴偏离基准点的距离；重心摇动波谱的谱质量分析。结果（1）睁闭眼立于平台60S的各参数中，以重心移动的外周面积及轨迹长度的变量能最精确地代表平衡功能．20～49岁正常人较20岁以下、50岁以上者重心移动的外周面积小、轨迹短，有统计学差异；（2）正常人重心在矢状面（Y轴）位移，大于冠状面（X轴）位移，且有统计学差异；（3）重心动摇的频谱分析，正常人与病人谱质量集中于0．2～1．9Hz的中频段，约占54～62％；其次是0．02～0．19Hz的低频约占24～30％；2～10Hz的高频段只点12～16％；（4）正常人睁闭眼轨迹长度比值均在1.32以下，末梢与中枢眩晕病人之比值分别为1．49及1．5，与正常人有统计学差异，说明眩晕者维持平衡更多依赖于视觉代偿。结论姿势图测定是无创性、定量检查方法，可以判断前庭功能状态，是继眼震电图以后，了解前庭系统功能的另一途径。     

突聋患者人体姿态平衡特征的临床分析

目的探究突聋患者人体姿态平衡的临床特征。方法采用人体姿态平衡仪,测试100例正常人和120例突聋患者重心晃动的轨迹图及相关参数值。根据前庭功能的情况,将120例突聋患者分为前庭功能正常组(67例)和异常组(53例),并比较二组重心晃动的长度、速度及Romberg参数值。结果正常人重心晃动的轨迹图以中心型多见(51%),而突聋患者则以弥散型为主(60.83%)。突聋患者重心晃动的长度、速度及Romberg参数值较正常人明显增大(P<0.01);前庭功能是否正常不影响重心晃动的参数值(P>0.05)。结论人体姿态平衡测试显示突聋患者前庭系统已受损。     

正常人与眩晕患者姿势图的定量研究

采用人体重心动摇计与计算机联机，测试６８名正常人及８２例中枢与末梢性眩晕患者的姿势图及有关参数，测试结果证明：①人体重心晃动轨迹分为中心型、前后型、左右型、多中心型、弥散型五种图形，正常人中心型多见，中枢性眩晕弥散型多见，末梢性眩晕介于二者之间；②正常人与患者各参数比较，眩晕患者晃动的轨迹长、速度大，与正常人比较差异有极显著性，中枢及末梢性病变组间比较差异无显著性；③正常人不同年龄组各项参数比较，２０岁组平衡功能最佳，重心晃动的面积小、轨迹短、速度慢，与５０岁以上组比较差异有极显著性，证明５０岁以后前庭功能开始衰变。     

蜗性听力损失对前庭脊髓反射影响的研究

目的通过姿势描记图检查对耳蜗性聋患者的前庭脊髓反射（vestibulospinal reflex,VSR）功能作定性及定量研究,以探讨耳蜗性聋对静态平衡能力的影响。方法用人体姿态平衡仪记录正常对照组和耳蜗性聋组重心移动的各项参数,主要包括重心晃动的路径总长和晃动速度,并将耳蜗性聋组重心移动的各项参数与正常对照组进行比较。结果听力损失≥71 dBHL的重度耳蜗性聋患者,重心轨迹晃动的路径总长长度明显延长,晃动速度明显增快,与正常对照组比较,路径总长之间的差异有统计学意义（P〈0.05）;闭眼状态下,晃动速度之间的差异有统计学意义（P〈0.01）。听力损失为41～70 dBHL的耳蜗性聋组病例与正常对照组之间的差异无统计学意义（P〉0.05）。结论重度耳蜗性聋（听力损失≥71 dBHL）的患者,前庭脊髓反射功能异常,静态平衡能力减弱。     

人体倾角姿态图仪对姿势平衡的定量研究

目的：探讨人体倾角姿态图仪检测姿势平衡的正常参考值。方法：应用人体倾角姿态图仪，以4种直立状态下的姿势摇摆平均角速度(ω)作为评价人体姿势平衡的惟一参数．对167例健康者按年龄段分组进行测试。结果：4种直立状态下的ω显示姿势平稳性与性别无关．与年龄有关，姿态平稳性在20～60岁时最佳；正常个体重心摇摆的方向性差异较大，但没有明显的倾斜方向。结论：判断是否有异常的姿势平衡．应与相应年龄组的正常值作对照。本测试数据可为该检测提供正常参考值；特别是球底平台闭眼检查，可更精确地鉴别出异常的前庭脊髓系统平衡功能。     

姿势描记法测试前庭脊髓反射对眩晕症的诊断价值

应用ＳＴ－９３９人体重心平衡仪；对４２例各型眩晕病人以姿势描记法进行前庭脊髓反射测试。结果示：（１）正常人与眩晕病人的各项指标差异有显著意义；（２）周围性与中枢性眩晕之间在重心移动图形及睁，闭眼参数比值方面差异亦有显著性；（３）小脑肿瘤病人的各项参数值小，ＰＧ异常率最高；（５）ＰＧ比ＥＮＧ敏感；（５）Ｒｏｍｂｅｒｇ指数及Ｘ／Ｙ商可提示视觉代偿作用大小和重心移动的方向性。     

≥80岁老人听,前庭及视动功能调查

目的：调查≥８０岁老人的听，前庭及视动功能变化，方法：用纯音测听及听性脑干反应测试听力功能；用眼震电图及姿态图测试半规管，视动及平衡功能；结果：（１）语频听力异常占８４．１％：（２）半规管功能和平衡功能异常者分别为３８．５％和７４．４％，与６０岁比较，重心晃动的轨迹长，速度大；（３）视动功能检查，≥８０岁老人扫视潜伏期延长，跟踪失真度加大。结论：随着年龄老化，≥８０岁老人半规管，视动，平衡功能，均     

前庭脊髓反射测试对梅尼埃病的应用价值

临床上常用Romberg试验检查病人的平衡功能,国内外已采用计算机化人体重心平衡仪—静平衡姿势描记法(posturogrphy,PG)对Romberg试验进行定量分析,了解前庭脊髓反射的异常情况。本室应用ST-939人体重心平衡仪(北京爱生电子技术研究所研制)测试眩晕病人。试图评估前庭脊髓反射测试的临床应用价值。 1 材料与方法临床诊断为梅尼埃病49例,平均年龄40.9岁,缓解期15例,发作期34例,均在发作后2天内测试PG。     

The role of the labyrinth, proprioception and plantar mechanosensors in the maintenance of an upright posture

The maintenance of an upright posture in man requires information from vision, the labyrinth, proprioception and plantar mechanosensors. In order to evaluate the role of the labyrinth, proprioception and plantar mechanosensors, stabilometry was performed in subjects with closed eyes. Ten patients with bilateral severe or complete labyrinthine paresis were studied, as well as 9 patients with severe proprioceptive disorders and 10 normal healthy persons whose plantar mechanosensors were anesthetized by hypothermia. Both the area of sway and the total locus length (accumulated shift distance length) were evaluated. On closing eyes, in patients with labyrinthine disorders demonstrated that the area of sway increased more than length. On the other hand, in patients with proprioceptive disorders, length increased more than the area. In plantar anesthetized subjects, similar to the labyrinthine disorder cases, the area of sway increased more than length. These findings suggest that the labyrinth is a main monitor of the area of body sway, while proprioception is a principle monitor of the velocity of body movement of sway (or locus length). The plantar mechanosensor monitors the area of body sway similar to the labyrinth, but works less than the labyrinth. The locus length is the distance per minute and reflects the velocity of body sway. Thus, the length per area is a parameter for the velocity of body sway per area. Since proprioceptive disorders increase both the locus length and the length per area, present findings suggest that if proprioception is damaged, the body begins to move faster. Compensated labyrinthine disorders have a tendency to increase the length per area, indicating that if a labyrinthine disorder is compensated, the body adapts and moves faster to maintain an upright posture.     

The role of the labyrinth,proprioception and plantar mechanosensors in the maintenance of an upright posture

The maintenance of an upright posture in man requires information from vision, the labyrinth, proprioception and plantar mechanosensors. In order to evaluate the role of the labyrinth, proprioception and plantar mechanosensors, stabilometry was performed in subjects with closed eyes. Ten patients with bilateral severe or complete labyrinthine paresis were studied, as well as 9 patients with severe proprioceptive disorders and 10 normal healthy persons whose plantar mechanosensors were anesthetized by hypothermia. Both the area of sway and the total locus length (accumulated shift distance length) were evaluated. On closing eyes, in patients with labyrinthine disorders demonstrated that the area of sway increased more than length. On the other hand, in patients with proprioceptive disorders, length increased more than the area. In plantar anesthetized subjects, similar to the labyrinthine disorder cases, the area of sway increased more than length. These findings suggest that the labyrinth is a main monitor of the area of body sway, while proprioception is a principle monitor of the velocity of body movement of sway (or locus length). The plantar mechanosensor monitors the area of body sway similar to the labyrinth, but works less than the labyrinth. The locus length is the distance per minute and reflects the velocity of body sway. Thus, the length per area is a parameter for the velocity of body sway per area. Since proprioceptive disorders increase both the locus length and the length per area, present findings suggest that if proprioception is damaged, the body begins to move faster. Compensated labyrinthine disorders have a tendency to increase the length per area, indicating that if a labyrinthine disorder is compensated, the body adapts and moves faster to maintain an upright posture.     

Postural adaptation in elderly patients with instability and risk of falling after balance training using a virtual-reality system

Our aim in this study was to assess postural control adaptation quantitatively in unsteady elderly patients at risk of falls in open spaces and given balance training with a virtual-reality system reproducing environmental stimulation. Using a balance rehabilitation unit based on a virtual-reality system that changes sensory information (visual, vestibular, and somatosensory), we treated 26 elderly, unsteady patients who were prone to falling (age range, 73-82 years) and who were enrolled in a customized vestibular rehabilitation program. We assessed postural responses by posturography before and after 6 weeks in the vestibular rehabilitation program under two conditions: (1) standing, eyes open, static visual field, and (2) standing, eyes open, dynamic visual field through virtual-reality goggles, generating horizontal optokinetic stimulation (70 degrees per second angular velocity). We recorded postural responses with a platform measuring the confidential ellipse of the center-of-pressure distribution area and sway velocity with a scalogram analyzing postural behavior by wavelets. After 6 weeks of treatment, postural response confidential ellipse and sway velocity values were lower, evincing decreased amplitudes and sway frequency contents in the scalogram by wavelet under both stimulation paradigm conditions. These findings suggest postural adaptation under the two perceptual conditions when patients had static and dynamic visual fields. The possibility of treating elderly fallers with balance disorders using a virtual-reality environmental stimulation reproduction system is discussed.     

Postural Stability of Preoperative Acoustic Neuroma Patients Assessed by Sway Magnetometry: Are They Unsteady?

OBJECTIVE: The objective was to evaluate the preoperative postural stability of acoustic neuroma patients using sway magnetometry. STUDY DESIGN: Prospective two-center study. METHODS: Fifty-one patients (mean age, 53 years) diagnosed with unilateral acoustic neuroma on magnetic resonance imaging at two tertiary referral centers were studied. Preoperatively, each patient had sway patterns (with eyes open and with eyes closed, and standing on foam) recorded for 120 seconds by sway magnetometry. Path length for 30 seconds was calculated. The Romberg coefficient (path length with eyes open divided by path length with eyes closed) was calculated. RESULTS: Forty-four percent of patients had abnormal path lengths with eyes open, and 49% with eyes closed. The Romberg coefficients were significantly lower than normal (P <.001; 95% CI, 0.19-0.87). Mean Romberg coefficient was 0.59 (normal value = 0.73), and all patients had a coefficient of less than 1. CONCLUSIONS: Half of preoperative acoustic neuroma patients are unsteady, exhibiting abnormal sway patterns based on path length measurements. The increase in sway path length demonstrable in normal subjects with eyes closed was significantly exaggerated in patients with acoustic neuroma.     

Effects of tinnitus on posture: a study of electrical tinnitus suppression

We investigated the effects of tinnitus on postural responses using posturography. Thirty-three tinnitus patients (19 female and 14 male) ranging in age from 33 to 67 years (mean age, 53) were selected randomly at our outpatient clinic. Nobody complained of dizziness. Posturographic examination was given before and after 30-minute electrical stimulation. Items tested were envelope area, area (root mean square), total length, total length-area, mean amplitude of lateral body sway (mx), and anteroposterior sway (my). Those parameters did not improve in patients without tinnitus relief. Two postural measures (envelope area and mx) showed significant improvement in patients with tinnitus relief. These effects appeared only on positions involving restricted visual feedback. In a comparison of postural measures in patients with and without tinnitus relief, all parameters except total length and mx improved significantly in patients with eyes open. Our study showed that aside from the auditory system, tinnitus can affect balance, implying that tinnitus may be a factor in increasing unsteadiness in patients with tinnitus.     

Effect of head orientation on human postural stability following unilateral vestibular ablation.

Effective interpretation of vestibular inputs to postural control requires that orientation of head on body is known. Postural stability might deteriorate when vestibular information and neck information are not properly coupled, as might occur with vestibular pathology. Postural sway was assessed in unilateral vestibulopathic patients before and acutely, 1, 4, and 18+ months after unilateral vestibular ablation (UVA) as well as in normal subjects. Postural equilibrium with eyes closed was quantified as scaled pk-pk sway during 20 s trials in which the support surface was modulated proportionally with sway. Subjects were tested with the head upright and facing forward, turned 45 degrees right, and 45 degrees left. Equilibrium was uninfluenced by head orientation in normal subjects. In contrast, patients after UVA showed both a general reduction in stability and a right/left head orientation-dependent asymmetry. These abnormalities adaptively recovered with time. It is concluded that vestibular inputs to postural control are interpreted within a sensory-motor context of head-on-body orientation.     

Nonsequential vector analysis of body sway in Menière's disease]

Body sway test which examines the vestibulo-spinal reflex is sensitive for evaluating vestibular dysfunction in patients with vertigo, dizziness or unsteadiness. Body sway is usually evaluated by measuring the length and area of traces on the force platform. However, it is not necessarily possible to evaluate abnormal body sway with these indicators because there is a discrepancy between sway length and area. In the present study, 8 directional vectro-posturography was developed and applied to the patients with Meniere's disease. Averaging of measurements at moving 3 points was used to eliminate high frequency noise over 4.92Hz. The subjects consisted of 66 patients with unilateral Meniere's disease and 31 normal controls. Eight directional vectrogram allowed measurement of shift area and directionality, simultaneously. The patient's group showed statistically significant body sway in the right forward and left backward direction with eyes open, in all the directions with eyes closed, when compared with the control's group. The effect of vision on postural stability was studied by obtaining 8 directional Romberg's quotients. The patients with Meniere's disease had significantly in forward-backward, and left-forward and right-backward direction when compared with controls. However, laterality of the affected side was not detected from the vectrogram. The effect of endolymphatic sac operation on postural stability was evaluated in the patients of unilateral Meniere's disease who showed progressive hearing loss and resisted conservative medication therapy. The results showed unstable body sway in the condition with eyes closed until at least 4 months after the operation. The patients with Meniere's disease presented pathological body sway, even during symptom free periods, when examined with 8 directional vector posturography. Power spectral analysis of body sway indicated that most energy was distributed at frequencies lower than 0.5Hz. Nevertheless, directional preponderance of body sway was characterized by higher frequency components. The findings infers that postural stability at the frequency range over 0.5Hz, may be governed by the input of vestibular organs.     

Postural stability after vestibular schwannoma surgery

Factors related to postural stability and the course of recovery after vestibular schwannoma surgery were analyzed in a retrospective study of 177 patients and in a prospective study of 44 patients. Before surgery, 7 of the 44 patients in the prospective group complained of postural instability. The body sway velocity was measured. In the retrospective study, the sway velocity was abnormal under nonvisual control in 63% of the patients and under visual control in 34%. The sway velocity correlated with tumor size, smooth pursuit deficit, and postoperative work history. We compared patients with abnormal postural control to those with normal postural control, and found that the former relied to a greater extent on visual information and the latter on proprioceptive information. In the prospective study, the sway velocity increased after the operation, and 1 year after surgery it had not returned to preoperative values. In the logistic regression analysis, a translabyrinthine approach, rehabilitation, the patient's age, and preserved function of the facial nerve predicted a good outcome of postural stability. The retrosigmoid approach and depression were the most significant risk factors for postoperative gait difficulties. Vestibular rehabilitation increased the reliance on proprioception for maintenance of postural control and improved postural stability.