Determining an optimal posturography dataset to identify standing behaviors in the post-stroke subacute phase. Cross-sectional study

BackgroundA key issue for posturography is the expression of robust results, in a simplified way. Most studies of individuals post-stroke concern the chronic phase, with small sample sizes.ObjectivesBy reducing the number of posturographic indices, we aimed to determine an optimal dataset and understand typical postural behaviors in the subacute post-stroke phase.MethodsIn this cross-sectional study ancillary to the DOBRAS cohort, individuals were assessed as soon they could complete a full posturography session (with and without vision) after a first hemispheric stroke. Body-weight distribution on the mediolateral (ML) axis, position of the center of pressure on the antero-posterior (AP) axis, and postural sway on both axes were computed. Balance ability in daily life was quantified with the Postural Assessment Scale for Stroke. Data were analyzed by principal component and hierarchical clustering analyses as well as multiple linear regression.ResultsWe enrolled 95 individuals (median age: 67.0 years [Q1; Q3 56.0; 72.0]; 68% males). Vision suppression had a marginal effect, only increasing postural sway. Regardless of the visual condition, posturographic behavior was captured by a set of 3 indices that explained almost all the information. One postural sway index (ML or AP) gave more information (48%) than both position indices (ML 26% and AP 15%). These 3 indices identified 3 standing behaviors: 1) stable and symmetric, 2) asymmetric, unstable, and positioned backward, and 3) very unstable and positioned forward. Balance ability in daily life was explained (49% of the information, 95%CI [35; 63]) by weight-bearing asymmetry and postural sway on the ML axis, which played an independent role (both p<10^?5), with similar impact.ConclusionsThree typical behaviors allow standing after stroke: described by only 3 posturographic indices. Weight-bearing asymmetry is not the primary parameter and should not be considered in isolation as an outcome. To increase the feasibility of posturography in the early subacute phase and to simplify evaluation sessions, trials could be limited to eyes open.RegistrationNCT03203109.     

The effects of high frequency subthalamic stimulation on balance performance and fear of falling in patients with Parkinson's disease

Background  

Balance impairment is one of the most distressing symptoms in Parkinson's disease (PD) even with pharmacological treatment (levodopa). A complementary treatment is high frequency stimulation in the subthalamic nucleus (STN). Whether STN stimulation improves postural control is under debate. The aim of this study was to explore the effects of STN stimulation alone on balance performance as assessed with clinical performance tests, subjective ratings of fear of falling and posturography.     

Reliability of the Good Balance System? for Postural Sway Measurement in Poststroke Patients

[Purpose] The purpose of this study was to examine test-retest reliability of the Good Balance system^® for measurement of postural sway in poststroke patients. [Subjects] Sixty chronic stroke patients (40 men and 20 women; age 63.08 years; stroke duration 16.45 months) participated in this study. [Methods] Postural sway was evaluated using a force platform system (Good Balance system, Metitur Oy, Jyvaskyla, Finland). Two examiners measured postural sway for all participants during two separate testing sessions. The second measurement was performed one week after the first measurement. Intraclass correlation coefficients [ICC_(2,1)] were used for estimation of reliability. [Results] The ICC (95% CI) for intra-examiner reliability was good to very good, ranging from 0.69 to 0.93 (0.53–0.96), and the ICC for inter-examiner reliability was good to very good, ranging from 0.85 to 0.98 (0.77–0.99). [Conclusion] The results of the current study indicated that the intra- and inter-examiner reliability of the Good Balance system^® for measurement of postural sway was good to very good. Therefore, we suggest that measurement of postural sway using the Good Balance system^® would be useful for clinical assessment in poststroke patients.Key words: Postural sway, Reliability, Stroke     

Clinical measurement of postural control in adults

Postural control is the ability to maintain equilibrium and orientation in a gravitational environment. Effective approaches for clinical measurement of postural control remain to be developed. This article summarizes important neurophysiological and clinical considerations for developing measurement tools to assess postural control in adults. The postural control system is divided into three basic functional components for assessment: 1) biomechanical components, 2) motor coordination components, and 3) sensory organization components.     

Clinical and laboratory measures of postural balance in an elderly population.

The objective of this cross-sectional study was to compare scores on the Balance Scale with laboratory measures of postural sway and other clinical measures of balance and mobility. Thirty-one elderly subjects were assessed on the clinical measures and the laboratory tests of postural sway while standing still and in response to pseudorandom movements of the platform. The average correlation between the Balance Scale and the spontaneous sway measures was -.55. It was slightly lower (r = -.38) for the same parameters measured during the pseudorandom tests. There were high correlations between the Balance Scale and the Balance Sub-Scale developed by Tinetti (r = .91), Barthel Mobility sub-scale (r = .67), and timed "Up and Go" (r = -.76). The Balance Scale was the most efficient measure (effect size > 1) to statistically discriminate between subjects according to their use of each type of mobility aide (walker, cane, no aids). These data contribute to existing information on the performance of the Balance Scale and supports the validity of the Balance Scale in this geriatric population.     

Biomechanical analysis of sit-to-walk in different Parkinson’s disease subtypes

BackgroundThe Parkinson’s disease Postural Instability and Gait Difficulty subtype is well-known to exhibit higher levels of gait and postural instability and higher frequency of falls. However, no studies have investigated the impact of Parkinson’s disease subtypes when performing a highly-challenging postural task, such as sit-to-walk. This task is often used daily and can highlight balance impairments. Thus, the aim of this study was to compare Tremor Dominant and Postural Instability and Gait Difficulty subtypes during sit-to-walk measured by performance, kinematic and kinetic analyses.MethodsTwenty-four people with Parkinson’s disease participated in this study, and were divided into two groups: Tremor Dominant (n = 14) and Postural Instability and Gait Difficulty subtype (n = 10). They performed the sit-to-walk under a time constraint (to pick up a phone placed 4 meters away in order to answer an urgent call). Sit-to-walk overall performance, kinetic and kinematic data were assessed as outcome measures.FindingsThe Postural Instability and Gait Difficulty group demonstrated a slower anteroposterior center-of-mass velocity at seat-off, a longer duration of transitional phase and poorer movement fluidity. Furthermore, the Postural Instability and Gait Difficulty group showed a longer sit-to-walk total time. These results indicate that the Postural Instability and Gait Difficulty group performed the task slowly and split the task into two subtasks (sit-to-stand and walking), rather than performing a single, continuous task.InterpretationThe Postural Instability and Gait Difficulty group is unable to perform the sit-to-walk continuously, which might reflect the clinical impairments observed in this Parkinson’s disease subtype.     

What is balance?

Balance is a term frequently used by health professionals working in a wide variety of clinical specialities. There is no universally accepted definition of human balance, or related terms. This article identifies mechanical definitions of balance and introduces clinical definitions of balance and postural control. Postural control is defined as the act of maintaining, achieving or restoring a state of balance during any posture or activity. Postural control strategies may be either predictive or reactive, and may involve either a fixed-support or a change-in-support response. Clinical tests of balance assess different components of balance ability. Health professionals should select clinical assessments based on a sound knowledge and understanding of the classification of balance and postural control strategies.     

Measurement of balance in computer posturography: Comparison of methods--A brief review

Some symptoms related to disequilibrium may not be detected by a clinical exam. Therefore, objective study is important in assessing balance. In this paper, methods to measure balance in computer posturography are compared. Center of pressure (COP) displacement, equilibrium score (ES) and postural stability index (PSI), the main measures of assessing balance are described and their merits and disadvantages are discussed. Clinicians should apply that measure which suits the specific strategies in a specific situation. Measuring devices such as Force plate, Balance Master and Equitest are also discussed. Although the Balance Master and Equitest devices are more costly compared to the force plate only, they are more useful for assessing balance relevant to daily life activities that might result in falls.     

Measures of postural stability

Dynamic posturography has become an important tool for understanding standing balance in clinical settings. A key test in the NeuroCom International (Clackamas, Oregon) dynamic posturography system, the Sensory Organization Test (SOT), provides information about the integration of multiple components of balance. The SOT test leads to an outcome measure called the "equilibrium score" (ES), which reflects the overall coordination of the visual, proprioceptive, and vestibular systems for maintaining standing posture. Researchers, therapists, and physicians often use the ES from the SOT as a clinically relevant measure of standing balance. We discuss here the formula used for evaluating the ES and propose an additional measure of postural stability, called the Postural Stability Index (PSI), that accounts for shear force and individual anthropomorphic measures. We propose that this new measure provides a clinically important adjunct to the current SOT and can be calculated from data already collected by the NeuroCom forceplate during the SOT.     

The assessment and treatment of postural disorders in cerebellar ataxia: A systematic review

Gait and balance disorders are often major causes of handicap in patients with cerebellar ataxia. Although it was thought that postural and balance disorders in cerebellar ataxia were not treatable, recent studies have demonstrated the beneficial effects of rehabilitation programs. This article is the first systematic review on the treatment of postural disorders in cerebellar ataxia. Nineteen articles were selected, of which three were randomized, controlled trials. Various aetiologies of cerebellar ataxia were studied: five studies assessed patients with multiple sclerosis, four assessed patients with degenerative ataxia, two assessed stroke patients and eight assessed patients with various aetiologies. Accurate assessment of postural disorders in cerebellar ataxia is very important in both clinical trials and clinical practice. The Scale for the Assessment and Rating of Ataxia (SARA) is a simple, validated measurement tool, for which 18 of the 40 points are related to postural disorders. This scale is useful for monitoring ataxic patients with postural disorders. There is now moderate level evidence that rehabilitation is efficient to improve postural capacities of patients with cerebellar ataxia – particularly in patients with degenerative ataxia or multiple sclerosis. Intensive rehabilitation programs with balance and coordination exercises are necessary. Although techniques such as virtual reality, biofeedback, treadmill exercises with supported bodyweight and torso weighting appear to be of value, their specific efficacy has to be further investigated. Drugs have only been studied in degenerative ataxia, and the level of evidence is low. There is now a need for large, randomized, controlled trials testing rehabilitation programs suited to postural and gait disorders of patients with cerebellar ataxia.     

Young type 1 diabetes subjects sway more than healthy persons when somatosensory system is challenged in static standing postural stability tests

In type 1 diabetes, it is important to prevent diabetes-related complications and postural instability may be one clinically observable manifestation early on. This study was set to investigate differences between type 1 diabetics and healthy controls in variables of instrumented posturography assessment to inform about the potential of the assessment in early detection of diabetes-related complications. Eighteen type 1 diabetics with no apparent complications (HbA1c = 58 ± 9 mmol/L, diabetes duration = 15 ± 7 years) and 35 healthy controls underwent six 1-min two feet standing postural stability tests on a force plate. Study groups were comparable in age and anthropometric and performed the test with eyes open, eyes closed (EC), and EC head up with and without unstable padding. Type 1 diabetics exhibited greater sway (path length, p = 0.044 and standard deviation of velocity, p = 0.039) during the EC test with the unstable pad. Also, power spectral density indicated greater relative power (p = 0.043) in the high-frequency band in the test with EC head up on the unstable pad and somatosensory activity increased more (p = 0.038) when the unstable pad was added to the EC test. Type 1 diabetes may induce subtle changes in postural control requiring more active balancing when stability is challenged. Postural assessment using a portable easy-to-use force plate shows promise in detecting a diabetes-related decline in postural control that may be used as a sensitive biomarker of early-phase diabetes-related complications.     

正常人动态平衡能力测试的信度及效度分析

目的　对正常人平衡功能进行动态姿势图重复检测 ,分析各参数间的内在一致性、重测信度及不同测试者间的信度 ;并与Berg平衡量表、功能性前伸测量、起立行走计时测定结果比较 ,检验其效标效度。方法　 2名测试者应用BiodexBalanceSystem (BBS)分别对 40名正常受试者 ( 18～ 67岁 )进行 2次 8级平台稳定性动态姿势图测试及稳定性测试 ;同时还应用Berg平衡量表、功能性前伸距离及起立行走计时等方法进行检测。结果　研究结果发现年龄因素对所有检测参数均有影响 ,体重指数对稳定指数及平均方向控制能力有影响。各参数间内部存在一致性 (r =0 .2 2～ 0 .93 ,均P <0 .0 1) ,其重测信度 (r =0 .70～ 0 .99)及不同测试者间信度 (r =0 .71～ 0 .98)较佳 (ICC =0 .88～ 0 .99)。在测试过程中 ,发现不同跌下次数的受试者其年龄差异和测试结果间差异显著相关 (P <0 .0 0 1)。BBS测试数据与Berg平衡量表、功能性前伸测量、起立行走计时测评结果有较高的相关性 (r =0 .72～ 0 .86)。结论　BBS能反映受试者平衡能力的年龄变化趋势 ,具有较高的内在一致性、重测信度及不同测试者间的信度 ,与Berg平衡量表、起立行走计时及功能性前伸测量结果具有一致性 ,可用于平衡功能的定量评定。     

Assessing postural balance in early Parkinson’s Disease—validity of the BDL balance scale

Background: There is a need for a valid assessment test of balance in early Parkinson’s disease (PD). Objective: To validate the Bäckstrand Dahlberg Liljenäs Balance Scale (BDL), a test of balance performance constructed to assess mild to moderate balance disability due to neurological disease, for use in persons with early PD. Methods: Cross-sectional psychometric evaluation study from a convenience sample community-dwelling persons with PD (n = 28). Main measures: The BDL was validated using the Berg Balance Scale (BBS), the motor part of the Unified Parkinson’s Disease Rating Scale (mUPDRS), the Timed Up and Go (TUG) and Timed Up and Go-cognition (CTUG). Correlations were calculated by Spearman’s rank correlation coefficient (rho). Rasch analyses were used to test the internal construct of the BDL. The result from the BDL was compared to a healthy reference group. Results: The correlation between the BDL and the BBS (rho = 0.703) was high positive, while for mUPDRS (rho = ?0.280), TUG (rho = ?0.321) and CTUG (rho = ?0.361) the correlations with the BDL were negligible to low negative. The Rasch analyses for the BDL showed a good distribution of the task difficulties with neither ceiling nor floor effect among individual measures. There was a significant difference (p = 0.03) in performance of the BDL between the PD group and the healthy reference group. Conclusions: The BDL Balance Scale can be considered a valid clinical assessment test when evaluating balance training interventions in persons with early PD. It can be recommended as an outcome measure in clinical practice and in clinical research within this population.     

The effects of incremental speed-dependent treadmill training on postural instability and fear of falling in Parkinson's disease

OBJECTIVE: To detect the effectiveness of incremental speed-dependent treadmill training on postural instability, dynamic balance and fear of falling in patients with idiopathic Parkinson's disease. DESIGN: Randomized controlled trial. SETTING: Ankara Education and Research Hospital, 2nd PM&R Clinic, Cardiopulmonary Rehabilitation Unit. SUBJECTS: Fifty-four patients with idiopathic Parkinson's disease in stage 2 or 3 of the Hoehn Yahr staging entered, and 31 patients (21 training, 10 control) had outcome data. INTERVENTIONS: Postural instability of patients with Parkinson's disease was assessed using the motor component of the Unified Parkinson's Disease Rating Scale (UPDRS), Berg Balance Test, Dynamic Gait Index and Falls Efficacy Scale. Twenty-one patients with Parkinson's disease participated in an eight-week exercise programme using incremental speed-dependent treadmill training. Before and after the training programme, balance, gait, fear of falling and walking distance and speed on treadmill were assessed in both Parkinson's disease groups. MAIN MEASURES: Walking distance and speed on treadmill, UPDRS, Berg Balance Test, Dynamic Gait Index and Falls Efficacy Scale. RESULTS: Initial total walking distance of the training group on treadmill was 266.45 +/- 82.14 m and this was progressively increased to 726.36 +/- 93.1 m after 16 training session (P < 0.001). Tolerated maximum speed of the training group on treadmill at baseline was 1.9 +/- 0.75 km/h and improved to 2.61 +/- 0.77 km/h (P < 0.001). Berg Balance Test, Dynamic Gait Index and Falls Efficacy Scale scores of the training group were improved significantly after the training programme (P < 0.01). There was no significant improvement in any of the outcome measurements in the control group (P > 0.05). CONCLUSIONS: Specific exercise programmes using incremental speed-dependent treadmill training may improve mobility, reduce postural instability and fear of falling in patients with Parkinson's disease.     

Effect of Resistance Exercise on Body Structure and Function,Activity, and Participation in Individuals With Parkinson Disease: A Systematic Review

ObjectiveTo investigate the effects of resistance exercise (RE) on body structure and function, activity, and participation in individuals with Parkinson Disease (PD) in the mild to moderate stages.Data SourcesMedline, Embase, Web of Science, The Cochrane Library, Lilacs, and PEDro were searched from inception until June 2020 using the terms “Parkinson Disease,” “Exercise,” “Resistance Training,” “Muscle Strength,” “Cardiorespiratory Fitness,” “Postural Balance,” “Gait,” and “Quality of Life.”Study SelectionWe included studies conducted in individuals with PD involving RE compared with a control group. Two independent reviewers performed the selection process based on titles, abstracts, and full-text reading. In total, 270 individuals with PD were included from 10 selected studies.Data extractionTwo reviewers independently extracted characteristics related to participants, intervention and control types, and results. The PEDro scale was used to assess the methodological quality, and the level of evidence was analyzed and synthesized using the Grading of Recommendation, Assessment, Development, and Evaluations approach.Data SynthesisThe level of evidence for body structure and function was low and without effect for lower limb muscle strength; very low and with effect for upper limb muscle strength, cardiorespiratory fitness, and postural balance; and very low and without effect for flexibility after RE training. For activity, the evidence was very low and with effect for gait and very low and without effect for mobility. For participation (ie, quality of life) the evidence was very low and without effect.ConclusionsAlthough the level of evidence was low to very low, RE was shown to promote improvements in body structure and function (upper limb muscle strength, cardiovascular function, postural balance) and activity (gait). In contrast, RE did not significantly improve participation (quality of life). However, based on the present findings, the practice of RE can be recommended for individuals with PD in the mild to moderate stages.     

Specific balance training included in an endurance-resistance exercise program improves postural balance in elderly patients undergoing haemodialysis

Purpose: The purpose of this study was to evaluate the effects of 6 months of specific balance training included in endurance-resistance program on postural balance in haemodialysis (HD) patients.

Methods: Forty-nine male patients undergoing HD were randomly assigned to an intervention group (balance training included in an endurance-resistance training, n?=?26) or a control group (resistance-endurance training only, n?=?23). Postural control was assessed using six clinical tests; Timed Up and Go test, Tinetti Mobility Test, Berg Balance Scale, Unipodal Stance test, Mini-Balance Evaluation Systems Test and Activities Balance Confidence scale.

Results: All balance measures increased significantly after the period of rehabilitation training in the intervention group. Only the Timed Up and Go, Berg Balance Scale, Mini-Balance Evaluation Systems Test and Activities Balance Confidence scores were improved in the control group. The ranges of change in these tests were greater in the balance training group.

Conclusions: In HD patients, specific balance training included in a usual endurance-resistance training program improves static and dynamic balance better than endurance-resistance training only.

• Implications for rehabilitation

• Rehabilitation using exercise in haemodialysis patients improved global mobility and functional abilities.

• Specific balance training included in usual endurance resistance training program could lead to improved static and dynamic balance.

     

Pilot study assessing balance in women with fibromyalgia syndrome

The purpose of current study was to assess postural control and balance self-efficacy in people with fibro-myalgia syndrome [FMS]. Thirty-two females with FMS completed the Activity-specific Balance Confidence Scale, Berg Balance test, NeuroCom Balance Master sensory-organization test, and limits of stability. There was a high prevalence of reported falls and a low mean score on the Activity-specific Balance Confidence Scale. A significant number of subjects scored below the population norm fifth percentile score on the sensory-organization test composite, visual, and vestibular sections. Preliminary evidence suggests that women with FMS may present with deficits in postural control, sensory organization, and balance self-efficacy.