Effects of Customized Vestibular Rehabilitation on Static balance among Adults with Benign Paroxysmal Positional Vertigo (Kesan Rehabilitasi Vestibular Disesuaikan Ke Atas Keseimbangan Static Dalam Kalangan Dewasa Dengan Masalah Benign Paroxysmal Positional Vertigo) / Jurnal Sains Kesihatan Malaysia

@#The aim of this study was to detemine the effectiveness of Customized vestibular rehabilitation (CVR) in addition to the standard Canalith repositioning maneuver (CRM) on static balance among adults with posterior canal Benign Paroxysmal Positional Vertigo (BPPV). In this randomised controlled trial, 28 adults with idiopathic unilateral posterior canal BPPV were randomized to either the control or experimental group. The experimental group (n=14, mean age: 50.71±9.88 years) received CVR in addition to CRM, and the control group (n=14, mean age: 54.36±8.55 years) received only CRM for 6 weeks. Measurements of static balance (postural sway) using a portable kinematic sensor were performed at baseline, four and six weeks after treatment for both groups while standing on firm and foam surface with eyes open (EO) and closed (EC). Only standing on foam surface with EC was observed to have a significant interaction effect, F (2, 52) =5.28, p<0.05. This suggest that the groups were affected differently by the intervention and greater improvement was demonstrated in the experimental group. Post hoc test showed that a significant difference (p<0.05) in static balance was shown between baseline and 6th week after intervention. The results of our study indicate that CVR in addition to CRM improved static balance in adults with UPC BPPV at 6th week after intervention for persons with BPPV.

The effects of stooped posture on gait and postural sway in Korean patients with Parkinson’s disease

@#Stooped posture, a forward trunk flexion, is a common clinical feature in patients with Parkinson’s disease (PD). However, the exact etiology and effects on gait and balance are not fully understood. In the present study we evaluated the effects of stooping on gait and balance using three-dimensional motion capture and clarified the relationship between the trunk angle and impaired motor function in patients with PD. Thirty-nine patients diagnosed with PD were enrolled in our study. All participants were asked to walk a 6-m tract at their preferred speed, gait parameters and trunk flexion angle were measured using a three-dimensional motion capture system. We analyzed the correlation between trunk angle and gait parameters including gait speed, length, and center of pressure distance for postural sway. Significantly negative correlations were observed between the trunk flexion angle and gait speed (r = -0.407, p = 0.010) and step length (r = -0.561, p < 0.001). Conversely, no correlation was found between trunk flexion angle and postural sway in static standing. We found that stooped posture destabilized gait pattern and did not affect postural sway in PD. Our result showed that stooped posture may not be a compensatory action for stabilizing gait and posture, but rather a symptom of PD.

Static and dynamic postural stability in subjects with and without chronic low back pain.

Background: The present study were undertaken to compare the static and dynamic postural stability among chronic low back pain and normal subjects. Most of the studies have been conducted on sports professionals. The present study focuses on recreationally active population, for which the activity levels are comparatively lesser. Methods: Thirty subjects (15 Chronic Low back Pain and 15 Normal subjects) were recruited randomly who’s demographic are not varied. The static and dynamic postural stability test namely postural sway meter and Star excursion balance test were analyzed. Data were analyzed using test of homogeneity and Independent sample t test. Results: Descriptive statistics reflected homogeneity of the study population. Independent sample t-test was used to compare values for static and dynamic stability between chronic low back pain and Normal subjects. It showed a statistically significant (P<0.05) difference in posterior and left lateral direction with t-value of -2.720 and -1.601 respectively for static stability. On the other hand, dynamic postural stability (SEBT) showed significant difference in all direction except on right leg; anteromedial, anterolateral and right and left posterior direction. Conclusions: Chronic low back pain group showed reduction in static and dynamic postural stability as compared to normals’.

Influence of leg dominancy over foot pressure and postural sway in middle age population: an observational study.

Background: The notion of limb dominance has been commonly used in the upper extremity, yet the two lower extremities are often treated as equal for clinical purposes. But both the lower limbs may not be perfectly symmetrical. There are conflicts of results with relation to leg dominancy, postural sway and foot pressure, which aided us to study the effect of lateralization on foot pressure and postural sway in middle age population. Methods: Thirty two normal subjects were recruited based on criteria, whose dominant lower limb was ascertained, Foot Pressure and postural sway was assessed by weighing scale and postural sway meter respectively. Results: Descriptive statistics and two way ANOVA were used as statistical analysis. Foot Pressure showed significant difference (P value <0.05) between dominant and non-dominant leg. On the other hand postural sway showed significant antero-lateral sway towards dominant side (P value <0.001). Conclusions: Lateralization of foot pressure is significant over dominant leg while postural sway is significant over anterolateral dominant side.

Normative data of postural sway by using sway meter among young healthy adults.

Background: Postural control involves controlling body’s position in space for dual purpose of stability and orientation. Postural stability or balance is defined as the ability to maintain the projected Center of motion (COM) within the limits of Base of Support (BOS). During quite stance there is a separate Center of Pressure (COP) under each foot. The net center of pressure lies between the feet and depend on each limb support. Normally no one stand erect, instead the body sways in small amount, mainly forward and backward. Thus quite stance is characterized by small amount of spontaneous postural sway. The device (sway meter) consists of inflexible 40 cm long rod with vertically mounted pen at its end. The rod was mounted 20 cm wide metal plate which wil be fitted at the level of PSIS (Posterior superior iliac spine) over lower back region of participants by firm belt. A low tech Sway meter was designed to address the needs of clinicians and researcher with limited resources (e.g. no access to force plates or motion laboratories). It is a useful field test, as it is compact, lightweight, has short administration and data processing time. Unlike otherlightweight and easily applied systems, such as accelerometers and gyroscopes, the Sway meter involves no electronics or computer processing. Thus, assessment can be conducted in a variety of community settings and health care facilities. Several research groups have found the Sway meter to be feasible for use in different populations of young and older people. The Sway meter has been used in numerous studies of balance as well as retrospective and prospective investigations of falls risk in older people. The purpose of study was to find out normative data of postural sway by using sway meter in among young adults and the validity of the Sway meter against the floor and foot print. Aim and objectives: To study the normative data of postural sway by using sway meter among young healthy adults, to study the normative data of postural sway by using sway meter among young healthy adults with eye open and eye close, to study the normative data of postural sway by using sway meter compare with the normal values of the lord’s and Sherrington’s study. Material and methods: The subjects were instructed to keep their hand by their sides during standing. Subjects were informed about procedure before starting. Duration of each trial was 30 second. A starting point was marked on the graph paper. At end of the 30 seconds, the rod of the sway meter was taken away from the graph sheet. 5-10 seconds rest was given during trial, but they were not allowed to move away from the foot print. The procedure was repeated for each trial. A total of six trials were taken including, 3 trial with eyes opened and 3 for eyes closed. Maximum duration for all trial was 6-7 minutes and maximum deviation in 3 trials was taken for analysis. Results: In eye open condition, in anterior direction, total 60 (100%) subjects are had sway in 0.1 to 2 cm. In Posterior direction, total 60(100%) subjects are had sway in 0.1 to 2 cm. In right lateraldirection, total 59 (98%) subjects had sway in 0.1 to 2 cm; remaining 1 (2%) subject had sway in 2.1 to 3 cm. In left lateral direction, total 56 (95%) subjects had sway in 0.1 to 2 cm; remaining 2 (3%) subjects had 2.1 to 3 cm sway and 2 (2%) subjects had 3.1 to 4 cm sway in left side. In eye closed condition, in anterior direction 57 (95%) subjects had 0.1 to 2 cm sway in anteriorly, but remaining 2 (3%) subjects had 2.1 to 3 cm sway, and 1 (2%) subject had 3.1 to 4 cm sway. In posterior direction 59 (98%) subjects had 0.1 to 2 cm sway in posterior; rest 1 2%) subject had nil sway in posterior. in right lateral direction 56 (93%) subjects had 0.1 to 2 cm sway, and rest of the 2(4%) subjects had nil sway, and 2 (3%) had 2.1 to 3 cm sway in right direction. In left lateral direction 57 (95%) subjects had 0.1 to 2 cm sway, and 1 (2%) subjects had nil sway, rest 2(3%) subjects had sway in 2.1 to 3 cm. Conclusion: It has been concluded that this study support the self constructed sway meter as a clinical tool for identifying sways in various directions (anterior, posterior, right lateral and left lateral). Similarly 100% of sway was seen in anterior and posterior direction with eye open.

Uso da informação somatossensorial adicional no controle postural: efeito da dominância manual / The use of additional somatosensory information on postural control: effect of handedness

Buscamos com o presente estudo investigar o efeito da dominância manual e da visão no uso da informação somatossensorial adicional fornecida pelo toque suave no controle postural. Quinze adultos jovens e destros permaneceram em pé sobre uma plataforma de força com a) olhos abertos ou fechados e b) braços ao lado do corpo ou o dedo indicador direito ou esquerdo tocando a barra fixa. A área do centro de pressão (CP), amplitude e velocidade médias do CP nas direções anteroposterior e médio-lateral foram avaliadas. Os resultados indicaram uma redução nas medidas nas condições de toque e aumento com os olhos fechados, exceto quando o toque foi realizado com dedo indicador direito. A força máxima foi maior para a mão direita, enquanto a sensibilidade cutânea e as forças aplicadas à barra foram similares entre os hemicorpos. Esses resultados sugerem um efeito da dominância manual e visão no uso da informação somatossensorial adicional no controle postural...

In this study we investigated the effect of handedness and vision on the use of additional somatosensory information provided by the light touch in postural control. Fifteen right-handed, young adults quietly stood on a force plate with a) eyes open or closed and b) arms hanging along the body or with the right or left index finger in contact with a rigid bar. We assessed the center of pressure (CP) area and CP mean sway amplitude and velocity in anterior-posterior and medial-lateral directions. The results revealed a reduction of these measures in the touch conditions and increase with the eyes closed, except when the touch was performed with right index fingertip. The grip strength was greater for the right hand, while the cutaneous sensitivity and the forces applied on the bar were similar between the two sides of the body. These results suggested an effect of the handedness and vision in the use of additional somatosensory information on the postural control...

Analysis on postural stabilization from visual feedback through Brownian motion modeling / 医用生物力学

Objective To explore postural stabilization of visual feedback to human body and its mechanisms. Methods Displacement of the center of pressure (COP) of 12 healthy young adult volunteers were investigated under upright posture with and without visual feedback conditions. The Brownian motion model was employed to compare the differences in diffusion coefficients, Hurst exponents, and critical points of the COP trajectories under the above two conditions, and one way repeated measures ANOVA was utilized to test the significance of these differences. ResultsUnder the visual feedback condition, in long-term time intervals, diffusion coefficients were reduced by about two thirds and Hurst exponents reduced by half; in short-term time intervals, no significant differences were found in diffusion coefficients in the medial-lateral (ML) direction and in Hurst exponents; in addition, the coordinates of the critical points presented no statistically significant differences in the time intervals except for the mean square displacement in the anterior posterior (AP) direction. ConclusionsVisual feedback enhances the closed-loop control mechanism of postural control, while it does not have great impact on the open-loop control mechanism and transitional characteristics of the two mechanisms; moreover, the effect of visual feedback on postural control in AP direction is more obvious than that in ML direction.

Quantitative Assessment and Age-related Analysis of Static Equilibrium in Elderly Individuals / 中国康复理论与实践

@#ObjectiveTo determine the static equilibrium of elderly individuals over the age of 60 and the correlation to the age. Methods142 elderly subjects (60～95 years old) were divided into 7 groups: 60～65 years old group, 66～70 years old group, 71～75 years old group, 76～80 years old group, 81～85 years old group, 86～90 years group, and >90 years old group, 24 cases 18～30 years old as the control. The static equilibrium was examined by measuring the stability index （ST） and the spectrum analysis of postural sway under following 4 conditions: standing on solid surface with eyes open （NO），standing on solid surface with eyes closed （NC）， standing on pillows with eyes open （PO）， and standing on pillows with eyes closed （PC） using Tetrax Balance System. ResultsThe ST and the intensity of postural sway increased in the elderly group compared with the control group. NO: there were significant differences (P<0.01) in ST, F1, F4, F6, F8 among the 81～85 years group, 86～90 years old group, >90 years old group and the control group. NC: there were significant differences (P<0.01) in ST, F1, F4 among all the elderly groups and the control group, and in F6, F8 among the >66 years groups and the control group（P<0.05）. PO: there were significant differences (P<0.01) in ST, F4, F6 among the >66 years old groups and the control group, and in F1, F8 among the >71 years old groups and the control group（P<0.05）. PC: there were significant differences (P<0.01) in ST, F4 among all the elderly groups and the control group, in F6 among the >66 years groups and the control group, in F8 among the >76 years old groups and the control group, and in F1 among the >80 years old groups and the control group（P<0.05）. The ST distributed as NOP<0.01）. There were similar changes in the intensity of postural sway of F1, F4, F6, F8 bands. ConclusionThere is the significant decline of the static equilibrium in the subjects aged 80 or over and no significant decline of the static equilibrium in the subjects aged 60～80 whose compensation in the static balance may decrease.

The Relationship between the Subjective Visual Vertical and Static Postural Balance in Stroke Patients / The Japanese Journal of Rehabilitation Medicine

It has been pointed out that a biased perception of the subjective visual vertical (SVV) in stroke patients might be related to balance deficits and impaired activities of daily living (ADL). The relationship between SVV and static balance in stroke patients, however, still remains unclear. Thus we examined the relationship between SVV and standing balance in 29 hemiparetic patients with a first-ever supratentorial stroke. We measured the rotation angle formed by a subjective vertical and the gravitational vertical (rotation to the non-paretic side was set as positive) 8 times, and employed the mean value as the SVV value. We also calculated the absolute rotation angle for each time and employed the mean value as the absolute SVV value. Then we evaluated postural balance using four stabilometer parameters : length of center of pressure per time (LNG/T), envelopment area (ENV), root mean square (RMS) and weight-bearing asymmetry (WBA) during standing. The relationship between the SVV values or the absolute SVV values and the four stabilometer parameters were analyzed using the Spearman's rank correlation coefficient. The mean values for SVV and absolute SVV of all participants were -0.3±2.3° and 2.0±1.5°, respectively. The absolute SVV value and each of the four parameters were positively correlated with statistical significance (LNG/T ; <i>r</i>=0.44, ENV ; <i>r</i>=0.41, RMS ; <i>r</i>=0.46, WBA ; <i>r</i>=0.40), while there was no statistically significant correlation between the SVV value and each of them. These results suggest that the SVV bias size is possibly related to standing balance in stroke patients.

A Pilot Study of the Efficacy of Interactive Virtual Reality Sports on Balance Performance among Older Women / Jurnal Sains Kesihatan Malaysia

This randomized control pilot study quantified the efficacy of interactive virtual reality golf training on balance performance among community mobile older person. Eight older women were assigned randomly to a conventional mat exercises program group (n = 4, mean age = 51 ± 1.6 years old) or an experimental group that participated in interactive virtual reality golf (n = 4, mean age = 53.5 ± 1.4 years old). Balance assessments of all participants included Multi-Directional Reach Test (MDRT), Step Up Test (SUT), Double Leg Static Balance (DLSB) with eyes open and closed and excursion of centre of pressure (COP) sway quantified with a force plate. One subject dropped out from the experimental group and three subjects from the conventional mat exercise group due to work commitments to complete the once a week study for four weeks. No significant differences in base-line balance abilities were found between groups. The experiment group did not have significant improvements in balance capability compared with control subjects (MDRT p = 0.16-0.66; SUT p = 0.05; COP during DLSB p = 0.18-0.66). However, virtual reality golf intervention improved medial-lateral sway by 57.24% during DLSB compared to 14.99% after floor-mat exercises. The improvement in COP during DLSB after interactive virtual reality golf hints towards improved postural control. Further studies with a larger population should explore using off-the shelf interactive virtual reality sports for balance training. This novel technology can complement rehabilitation programs.

Comparação da oscilação postural estática na posição sentada entre jovens e idosos saudáveis / Comparing static sitting postural sway of healthy young and older adults

OBJETIVOS: Descrever uma nova metodologia de análise da oscilação postural estática sentada e comparar os resultados de jovens e idosos saudáveis. MÉTODOS: Participaram do estudo 38 indivíduos saudáveis, 17 jovens (idade média 23±2,38 anos) e 21 idosos (idade média 67±2,42 anos). A oscilação postural foi mensurada por meio do sistema eletromagnético Polhemus® 3Space Isotrack II. As avaliações foram feitas nas condições olhos abertos (OA) e fechados (OF), com os voluntários sentados sem apoio plantar e sem encosto em suportes de madeira (superfície estável-SE) e de espuma (superfície instável-SI). Cada condição sensorial foi avaliada durante 90 segundos. Os parâmetros analisados foram: deslocamento máximo (Dmáx), trajetória total (Traj) e velocidade média (Vel) nos planos sagital (X) e frontal (Y). RESULTADOS: Nas condições OA e OF em SE, foram encontradas oscilações nos planos X e Y dos parâmetros Traj e Vel maiores em jovens que em idosos. Em SI, foram observadas maiores Traj Y e Vel Y nos jovens, sem diferença significativa entre os grupos quanto a Traj X e Vel X com olhos fechados. Em relação ao Dmáx, tanto no plano X quanto no Y, em todas as condições sensoriais, só houve diferença significativa na condição OASE no plano sagital, sendo maior nos jovens. CONCLUSÕES: Jovens saudáveis oscilam mais que os idosos saudáveis na posição sentada. Além disso, a ferramenta utilizada mostrou ser útil para análise da oscilação postural estática na posição sentada, possibilitando o surgimento de estudos que a associem com o efeito de diversas tarefas motoras.

OBJECTIVES: To describe a new method to analyze the static sitting postural sway and to compare the results of healthy young and older adult subjects. METHODS: Thirty-eight healthy subjects took part in the study, including 17 young adults (mean age 23±2.38 years old) and 21 older adults (mean age 67±2.42 years old). The device used to quantify trunk sway was the magnetic field sensor Polhemus® 3Space Isotrack II. The measurements were taken in the eyes-opened (EO) and eyes-closed (EC) condition with the subjects seated first on a wooden stable surface (SS) then on a foam unstable surface (US) without back or foot support. Each sensory condition was assessed for 90 seconds. The analyzed parameters were: maximum amplitude (Amp), total trajectory (Traj) and mean velocity (Vel) in the sagittal (X) and frontal (Y) planes. RESULTS: In the EO and EC conditions on SS, young adults presented greater postural sway in the X and Y planes on the Traj and Vel parameters. In the US, young adults showed greater Y Traj and Y Vel in the EO and EC conditions, and there was no significant difference between the groups with regard to X Traj and X Vel in the EC condition. The young adults presented greater Amp only in the EOSS condition in the X plane. CONCLUSIONS: The young adult subjects presented greater sway in the sitting position than the older adult subjects. In addition, the Polhemus® device was a useful tool to analyze static sitting postural sway and can be used in future studies that associate static sitting postural sway with the effect of various motor tasks.

The Effects of Transcutaneous Electrical Nerve Stimulation for Standing Balance in Patients with Hemiplegia

OBJECTIVE: To evaluate the effects of transcutaneous electrical nerve stimulation (TENS) applied at lower extremity for standing balance in patients with hemiplegia. METHOD: Twenty-two hemiplegic patients were tested while standing on balance trainer under eight stimulation modes (No TENS, bilateral TENS, hemiplegic TENS, and unaffected TENS. These four conditions were applied both with and without vision). All patients were able to stand independently more than five minutes. TENS was applied with pulse width 200micron s, frequency of 100 Hz, amplitude set at the sensory detection threshold of each patients. TENS was applied thirty seconds for each stimulation modes, and resting period was 10 minutes. Postural sway was determined during the testing period by the sum of anterior-posterior (AP) center of pressure (COP) sway, medio-lateral (ML) COP sway, and total sum of COP sway. Also postural sway was determined by proportion of time of COP in three circles, which semidiameters are 10 mm, 20 mm, 30 mm each. RESULTS: When patients were applied with TENS eyes closed at the unaffected lower extremity, AP, ML, and total sum of COP sway decreased significantly. CONCLUSION: In hemiplegic patients with independent standing, TENS application at the unaffected leg over five minutes can be helpful standing balance enhancement.

The Effect of Laterally Wedged Insoles on Standing Balance of Patients with Osteoarthritis in the Medial Compartment of Knees

OBJECTIVE: To investigate the effect of laterally wedged insole on static balance of patients with degenerative osteoarthritic knees. METHOD: Eighteen female patients were diagnosed with medial compartment knee degenerative osteoarthritis (OA) based on symptoms and simple X-rays. Patients were studied while they stood wearing shoes with the 5 degrees or 10 degrees lateral wedged insoles compared with a bare foot. Patients chose a comfortable stance with feet spread apart, slightly turned outwards, and were asked to look straight ahead at a fixed point in a quiet room. Postural sway and weight load asymmetry were recorded while the patients were standing on two adjacent force platforms during a 30 second trial. RESULTS: Postural sway and weight load asymmetry for 30 seconds were not significantly changed by wearing laterally wedged insoles with varying elevations (p>0.05). CONCLUSION: The degree of the postural sway and weight load asymmetry for 30 seconds with the insole were not affected by the tilt of the lateral wedge.

Postural Sway and Limb Load Asymmetry in the Rural Inhabitants in Korea

OBJECTIVE: To evaluate the effects of age, height, weight, body mass index (BMI), diabetes mellitus, osteoporosis, smoking and alcohol on postural sway (PS) and limb load asymmetry (LLA) in the rural inhabitants in Korea METHOD: Nine hundred and sixty inhabitants were included in this study. PS and LLA were recorded while the subjects were standing on two adjacent force platforms (Mediance(R); Human-Tech Inc, Korea) in a comfortable stance for 30 seconds. Bone mineral density was measured in the right calcaneus by ultrasonography (Sahara(R); Hologic Inc, USA). History of diabetes and smoking were taken through interview. RESULTS: PS and LLA were correlated with age (p<0.01). There were significant decreases in PS and LLA in the young age-group (p<0.01). There was no significant difference in PS and LLA in terms of sex, osteoporosis, height, weight, BMI and smoking. There was a significant difference in LLA (p<0.05) but no difference in PS between diabetic and normal groups. CONCLUSION: PS and LLA may be related with ageing. Diabetic group may have higher LLA than normal group. However, sex, osteoporosis, height, weight, BMI, and smoking may not affect on PS and LLA.

Factors Affecting Hand Tremor and Postural Sway in Children

Objectives: It is crucial to consider covariates relevant for outcome variables in developing dose-effect relations of environmental hazardous toxins. The aim of this study was to clarify the covariates affecting hand tremor and postural sway in children. Methods: Hand tremor and postural sway, as well as hair mercury concentrations, were measured in 155 boys and 148 girls at age 7 years. Results: Current mercury concentrations in child hair ranged from 0.35 to 6.32 μg/g (geometric mean, 1.71 μg/g for boys and 1.58 μg/g for girls), and were not significantly correlated with the neuromotor parameters. All hand tremor and postural sway parameters, except for tremor intensity at 1–6 Hz with non-dominant hand, were significantly larger in the boys than in the girls. Using multiple regression analysis, some postural sway parameters were related negatively to age in the boys and girls (p<0.05), and positively to height (p<0.05). Similarly, hand tremor parameters were positively related to age, height and heart rate either in the boys or in the girls (p<0.05). Also, there were positive relationships between tremor intensity at 1–6 Hz and transversal and sagittal sways at 1–2 Hz and 2–4 Hz (p<0.05). Conclusions: Heart rate and postural sway, together with age, sex, and height, should be considered in interpreting hand tremor in children. Hand tremor or postural sway may not be so sensitive or specific to methylmercury exposures at levels of less than 7 μg/g in hair.

Factors affecting hand tremor and postural sway in children

<p><b>OBJECTIVES</b>It is crucial to consider covariates relevant for outcome variables in developing dose-effect relations of environmental hazardous toxins. The aim of this study was to clarify the covariates affecting hand tremor and postural sway in children.</p><p><b>METHODS</b>Hand tremor and postural sway, as well as hair mercury concentrations, were measured in 155 boys and 148 girls at age 7 years.</p><p><b>RESULTS</b>Current mercury concentrations in child hair ranged from 0.35 to 6.32 μg/g (geometric mean, 1.71 μg/g for boys and 1.58 μg/g for girls), and were not significantly correlated with the neuromotor parameters. All hand tremor and postural sway parameters, except for tremor intensity at 1-6 Hz with non-dominant hand, were significantly larger in the boys than in the girls. Using multiple regression analysis, some postural sway parameters were related negatively to age in the boys and girls (p<0.05), and positively to height (p<0.05). Similarly, hand tremor parameters were positively related to age, height and heart rate either in the boys or in the girls (p<0.05). Also, there were positive relationships between tremor intensity at 1-6 Hz and transversal and sagittal sways at 1-2 Hz and 2-4 Hz (p<0.05).</p><p><b>CONCLUSIONS</b>Heart rate and postural sway, together with age, sex, and height, should be considered in interpreting hand tremor in children. Hand tremor or postural sway may not be so sensitive or specific to methylmercury exposures at levels of less than 7 μg/g in hair.</p>

Computerized Dynamic Posturography and Diabetic Peripheral Neuropathy

BACKGROUNDS: Peripheral neuropathy secondary to diabetes mellitus is believed to cause postural insta- bility which is associated with an increased risk of falling. Posturography enables early detection of postural control failure. This study is to evaluate the relationship between postural sway assessed by a computerized dynamic posturography and peripheral neuropathy in diabetic patients who have not develo- ped clinical symptom of unsteadiness. METHODS: Computerized dynamic posturography and electrophysiological tests were performed in the following age-matched subjects: 40 type 2 diabetic patients without peripheral neuropathy, 30 type 2 dia- betic patients with peripheral neuropathy, and 30 healthy control subjects. Patients had no symptoms or clinical evidence of postural instability. RESULTS: Sensory organization test showed significant dysfunction of somatosensory function of type 2 diabetic patients with peripheral neuropathy. Posturographic parameters were all significantly impaired in the patients with peripheral neuropathy. There were no significant differences in posturographic parameters between diabetic patients without neuropathy and the healthy control subjects. Posturographic parameters showed a direct relationship with some parameters of peripheral nerve conduction. CONCLUSION: Computerized dynamic posturography showed that Type 2 diabetic patients with peripheral neuropathy have greater postural instability than those without neuropathy. A strong correlation of insta- bility with peripheral neuropathy is present in diabetic patients. This result implies that peripheral neuro- pathy plays an essential role in the instability in type 2 diabetic patients. Posturographic study allows a disclosure of the failure of postural control even in the absence of clinical evidence of postural instability.

Quantitative Assessment of Static and Dynamic Postural Sway Using COBETS in Patients with Balance Problem

Ability to control postural balance is a prerequisite for standing and gait training during the period of rehabilitation in patients with balance disorder. Precise and quantitative assessment of balance deficit as well as development of effective training methods are the important areas of research in the field. The purposes of this study are (1) to assess the test-retest reliability and clinical feasibility of Computerized Balance Evaluation and Training System (COBETS) developed by Department of Medical Engineering and Department. of Rehabilitation Medicine at Chonbuk National University and (2) to quantitatively assess the static and dynamic postural control ability of the patients with balance disorders due to various causes using COBETS and compare them with the results of normal control subjects. The subjects consist of 21 patients with brain damage by stroke, head injury, or surgical procedure to control intractable epilepsy, 5 patients with lower extremity amputation, 6 patients with unilateral total hip replacement, and 50 normal control subjects, Fifteen out of 50 normal control subjects performed subsequent two trials to evaluate the test-retest reliability of the COBETS. There was no statistically significant difference between the results of first and second trials in static and dynamic postural sway measured by the patients with brain damage, amputation, and hip joint replacement, static postural sways during comfortable, narrow, and affected one-leg stance were significantly increased than normal control subjects. Abnormal results in somatosensory evoked potential study and presence of motor weakness were negatively influenced to the results of static postural-sway. In all the patients groups. The movement time, path error, and peripheral sway were markedly increased in forward and affected lateral directions compared with normal subjects. Abnormal sensory and motor findings also negatively influenced to some parameters of dynamic postural control. However, there was no difference in the postural sway among the patients groups divided by the causes of balance disorder. The COBETS is considered as a reliable and clinically useful too for quantitative as sessment of static and dynamic postural control in the patients with balance disorders. Its usefulness for the training of balance control is subject to be defined in future.