Intensity of challenge to the balance system is not reported in the prescription of balance exercises in randomised trials: a systematic review

QUESTION

How has balance challenge intensity been reported in trials of balance exercise interventions? Are there any instruments designed to measure the intensity of balance challenge in balance training exercises?

DESIGN

Systematic review of randomised trials of balance training exercises.

PARTICIPANTS

Older adults, ie, the majority of subjects were aged over 55 years.

INTERVENTION

Balance exercise intervention, or multi-dimensional intervention that included a balance exercise intervention.

OUTCOME MEASURES

The included trials were examined for descriptions and instruments used to report the intensity of the challenge to the patient's balance system provided by the balance exercise prescribed. The other included studies were examined for instruments that measure balance challenge intensity.

RESULTS

In most of the 148 randomised trials identified, measures of reported balance challenge 'intensity' were actually measures of some other aspect of the exercise, eg, aerobic intensity or a hierarchy of task difficulty without reference to the patient's ability. Three potential systems of measuring the balance challenge intensity were identified. Two were not described in any detail. One was defined in terms of the limits of the patient's postural stability, but this system appears not to have been validated. No adequate measures of balance challenge intensity were found among the other types of studies identified.

CONCLUSION

The review highlights a serious gap in the methods used to prescribe, implement, and evaluate the effect of balance exercise programs. Comprehensive work in this area is required to develop a psychometrically sound measure of balance exercise intensity.

The effects of horseback riding simulator exercise on postural balance of chronic stroke patients

[Purpose] The aim of this study was to examine the effects of horseback riding simulator exercise on postural balance of chronic stroke patients. [Subjects] A total of 67 stroke patients were assigned either to a horseback riding simulator exercise group (HEG, n=34) or a mat exercise group (MEG, n=33). [Methods] The subjects exercised three times per week for 8 weeks. Static balance ability was determined by eyes open balance (EOB) and eyes closed balance (ECB), which was measured using a Kinesthetic Ability Trainer Balance system. Dynamic balance was evaluated using the Berg balance scale (BBS). [Results] EOB and ECB significantly decreased and BBS had significantly increased after the intervention in the HEG and the MEG, and ECB decreased and BBS increased significantly more in the HEG than in the MEG. [Conclusion] Horseback riding simulator exercise is more effective than mat exercise for improving the ECB and BBS of stroke patients.

Effect of different insoles on postural balance: a systematic review

[Purpose] The aim of the present study was to perform a systematic review of the literature on the effect of different insoles on postural balance. [Subjects and Methods] A systematic review was conducted of four databases. The papers retrieved were evaluated based on the following inclusion criteria: 1) design: controlled clinical trial; 2) intervention: insole; 3) outcome: change in static postural balance; and 4) year of publication: 2005 to 2012. [Results] Twelve controlled trials were found comparing the effects of different insoles on postural balance. The papers had methodological quality scores of 3 or 4 on the PEDro scale. [Conclusion] Insoles have benefits that favor better postural balance and control.

Influence of Isokinetic Strength Training of Unilateral Ankle on Ipsilateral One-legged Standing Balance of Adults

[Purpose] The purpose of the current study was to investigate the changes in one-legged standing balance of the ipsilateral lower limb following unilateral isokinetic strength training. [Subjects and Methods] Thirty healthy adult volunteers were randomly assigned to either a training group or a control group, so that each group included 15 subjects. Subjects in the training group performed unilateral ankle isokinetic exercises of the dominant leg using the Biodex 3 PRO System for a period of four weeks. Ipsilateral one-legged standing balance was evaluated before and after the intervention with three stability indexes of balance using the Biodex System: Anterior-Posterior Stability Index (APSI), Medial-Lateral Stability Index (MLSI), and Overall Stability Index (OSI). [Results] Comparison of pre- and post-test data revealed significant improvements in strength values (dorsiflexion, plantarflexion, eversion, and inversion) and stability indexes (APSI, MLSI, OSI). [Conclusion] These results suggest that ankle strengthening exercise can be considered as a form of exercise that may assist individuals with improvement of balance.

Instrumenting the balance error scoring system for use with patients reporting persistent balance problems after mild traumatic brain injury

OBJECTIVE

To determine whether alterations to the Balance Error Scoring System (BESS), such as modified conditions and/or instrumentation, would improve the ability to correctly classify traumatic brain injury (TBI) status in patients with mild TBI with persistent self-reported balance complaints.

DESIGN

Cross-sectional study.

SETTING

Outpatient clinic.

PARTICIPANTS

Subjects (n=13; age, 16.3±2y) with a recent history of concussion (mild TBI group) and demographically matched control subjects (n=13; age, 16.7±2y; control group).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Outcome measures included the BESS, modified BESS, instrumented BESS, and instrumented modified BESS. All subjects were tested on the noninstrumented BESS and modified BESS and were scored by visual observation of instability in 6 and 3 stance conditions, respectively. Instrumentation of these 2 tests used 1 inertial sensor with an accelerometer and gyroscope to quantify bidirectional body sway.

RESULTS

Scores from the BESS and the modified BESS tests were similar between groups. However, results from the instrumented measures using the inertial sensor were significantly different between groups. The instrumented modified BESS had superior diagnostic classification and the largest area under the curve when compared with the other balance measures.

CONCLUSIONS

A concussion may disrupt the sensory processing required for optimal postural control, which was measured by sway during quiet stance. These results suggest that the use of portable inertial sensors may be useful in the move toward more objective and sensitive measures of balance control postconcussion, but more work is needed to increase sensitivity.

The effect of post-stroke lower-limb spasticity on the control of standing balance: Inter-limb spatial and temporal synchronisation of centres of pressure

BACKGROUND

Challenges in stability control are common post-stroke. Although lower-limb spasticity is a common sensorimotor consequence post-stroke, its potential to further complicate stability control among stroke-survivors remains largely unknown. Advancing such understanding can help inform strategies to reduce fall risk and increase independence among these individuals. The purpose of this study was to characterise the extent of limb-specific dyscontrol among individuals with spasticity.

METHODS

A retrospective analysis of 131 patients assessed for spasticity was performed. Patients selected for inclusion were categorised into two groups, with (n=19) or without (n=63) unilateral lower-limb spasticity. Two force platforms were used to determine the individual-limb and net centres of pressure in both anteroposterior and mediolateral directions during 30s of quiet standing. Limb-specific dyscontrol was assessed by calculating weight-bearing symmetry ratios, cross-correlation coefficients at zero phase-shift (temporal synchrony) and ratios of individual-limb root-mean-square displacements (spatial symmetry). Total body postural control was assessed by examining the root-mean-square of the net centre of pressure displacement.

FINDINGS

The group with spasticity bore less weight on the affected limb and exhibited reduced temporal synchrony of centre of pressure displacements. There were no differences in inter-limb root-mean-square centre of pressure ratios or in the root-mean-square of the net centre of pressure displacement.

INTERPRETATION

Individuals with lower-limb spasticity may have additional challenges with stability control, specifically linked to the ability to modify the location of the centre of pressure beneath the affected limb, in a time-sensitive manner so as to contribute beneficially to the control of whole body stability.

Effects of uni- and multimodal cueing on handrail grasping and associated gaze behavior in older adults

INTRODUCTION

It appears that age-related changes in visual attention may impair ability to acquire the visuospatial information needed to grasp a handrail effectively in response to sudden loss of balance. This, in turn, may increase risk of falling. To counter this problem, we developed a proximity-triggered cueing system that provides a visual cue (flashing lights) and/or verbal cue ("attention use the handrail") to attract attention to the handrail. This study examined the effect of handrail cueing on grasping of the rail and associated gaze behavior in a large cohort (n=160) of independent and ambulatory older adults (age 64-80).

METHODS

The handrail and cueing system was mounted on a large (2 m×6 m) motion platform configured to simulate a real-life environment. Subjects performed a daily-life task that required walking to the end of the platform, which was triggered to perturb balance by moving suddenly when they were adjacent to the rail. To prevent adaptation, each subject performed only one trial, and a deception was used to ensure that the perturbation was truly unexpected. Each subject was assigned to one of four cue conditions: visual, verbal, multimodal (visual-plus-verbal) or no cue.

RESULTS

Verbal cueing attracted overt visual attention to the handrail and markedly increased proactive grasping (prior to the onset of the balance perturbation) particularly when delivered unimodally. Subjects were otherwise much more likely to grasp the rail in reaction to the perturbation. A possible trend for visual cueing to improve the accuracy of these reactions was offset by adverse effects on reaction speed and on frequency of proactive grasping.

CONCLUSIONS

The results support the viability of using unimodal verbal cueing to reduce fall risk by increasing proactive handrail use. Conversely, they do not strongly support use of visual cueing (either alone or in combination with verbal cueing) and suggest that it may even have adverse effects. Further study is needed to evaluate effects of handrail cueing in a wide range of populations and real-life settings.

Visual biofeedback balance training using wii fit after stroke: a randomized controlled trial

[Purpose] The aim of the present study was to investigate the effect of balance training with visual biofeedback on balance, body symmetry, and function among individuals with hemiplegia following a stroke. [Subjects and Methods] The present study was performed using a randomized controlled clinical trial with a blinded evaluator. The subjects were twenty adults with hemiplegia following a stroke. The experimental group performed balance training with visual biofeedback using Wii Fit(®) together with conventional physical therapy. The control group underwent conventional physical therapy alone. The intervention lasted five weeks, with two sessions per week. Body symmetry (baropodometry), static balance (stabilometry), functional balance (Berg Balance Scale), functional mobility (Timed Up and Go test), and independence in activities of daily living (Functional Independence Measure) were assessed before and after the intervention. [Results] No statistically significant differences were found between the experimental and control groups. In the intragroup analysis, both groups demonstrated a significant improvement in all variables studied. [Conclusion] The physical therapy program combined with balance training involving visual biofeedback (Wii Fit(®)) led to an improvement in body symmetry, balance, and function among stroke victims. However, the improvement was similar to that achieved with conventional physical therapy alone.

Standing data disproves biomechanical mechanism for balance-based torso-weighting

OBJECTIVE

To test a proposed mechanism for the effect of balance-based torso-weighting (BBTW) in people with multiple sclerosis (MS) and healthy controls. The mechanism to be tested is that application of light weights to the trunk may result in a biomechanical shift of postural sway in the direction of weighting, mechanically facilitating maintenance of the center of mass over the base of support.

DESIGN

Nonrandomized controlled trial.

SETTING

Motion analysis laboratory.

PARTICIPANTS

Participants with MS (n=20; average Expanded Disability Status Scale score, 4.1) and controls matched for sex, age, height, and weight (n=18).

INTERVENTION

Light weights strategically placed according to the BBTW protocol were applied to all participants after at least 3 walking trials and 10 seconds of quiet standing with feet together and eyes open and then eyes closed. Measures were repeated after weighting.

MAIN OUTCOME MEASURE

Forceplate center of pressure (COP) changes >1 standard error of measurement.

RESULTS

With BBTW, people with MS had larger maximum changes in COP than healthy controls in the left-right direction but not in the anterior-posterior direction. COP changes >1 standard error of measurement occurred in the same direction of weighting 20% of the time (95% confidence interval, 5-34), ranging from 10% to 28% across conditions and directions of postural sway. Direction of greatest weight placement did not match the direction of change in the average COP in most participants with MS or the healthy controls in eyes open or eyes closed conditions (P<.001).

CONCLUSIONS

If BBTW worked via a biomechanical shift of the center of mass, COP changes should match the direction of greatest weighting with BBTW. Our data allowed us to reject this hypothesis. Future research may explore alternative mechanisms of action underlying this intervention.

Changes in balancing ability of athletes with chronic ankle instability after foot orthotics application and rehabilitation exercises

Objective

To compare the effect of foot orthotics and rehabilitation exercises by assessing balancing ability and joint proprioception in athletes who have chronic ankle instability.

Methods

Forty-one athletes who visited hospitals due to chronic ankle instability were randomly assigned to two groups. One group had ankle rehabilitation exercises while the other group had the same rehabilitation exercises as well as foot orthotics. Joint position sense of the ankle joint was examined by using an isokinetic exercise machine. Balancing abilities categorized into static, dynamic and functional balance abilities were evaluated by using computerized posturography. We tested the subjects before and after the four-week rehabilitation program.

Results

After the four-week treatment, for joint reposition sense evaluation, external 75% angle evaluation was done, revealing that the group with the application of foot orthotics improved by -1.07±1.64 on average, showing no significant difference between the two groups (p>0.05). Static, dynamic and functional balancing abilities using balance masters were evaluated, revealing that the two groups improved in some items, but showing no significant difference between them (p>0.05).

Conclusion

This study found that athletes with chronic ankle instability who had foot orthotics applied for four weeks improved their proprioceptive and balancing abilities, but did not show additional treatment effects compared with rehabilitation exercise treatment.

Cognitive-motor interference during functional mobility after stroke: state of the science and implications for future research

Cognitive-motor interference (CMI) is evident when simultaneous performance of a cognitive task and a motor task results in deterioration in performance in one or both of the tasks, relative to performance of each task separately. The purpose of this review is to present a framework for categorizing patterns of CMI and to examine the specific patterns of CMI evident in published studies comparing single-task and dual-task performance of cognitive and motor tasks during gait and balance activities after stroke. We also examine the literature for associations between patterns of CMI and a history of falls, as well as evidence for the effects of rehabilitation on CMI after stroke. Overall, this review suggests that during gait activities with an added cognitive task, people with stroke are likely to demonstrate significant decrements in motor performance only (cognitive-related motor interference), or decrements in both motor and cognitive performance (mutual interference). In contrast, patterns of CMI were variable among studies examining balance activities. Comparing people poststroke with and without a history of falls, patterns and magnitude of CMI were similar for fallers and nonfallers. Longitudinal studies suggest that conventional rehabilitation has minimal effects on CMI during gait or balance activities. However, early-phase pilot studies suggest that dual-task interventions may reduce CMI during gait performance in community-dwelling stroke survivors. It is our hope that this innovative and critical examination of the existing literature will highlight the limitations in current experimental designs and inform improvements in the design and reporting of dual-task studies in stroke.

Physiological load and posture control thresholds

The aim of the study was to evaluate the influence of the physiological load on postural control. Special attention was directed toward the identifying the intensity level in which the major deterioration in balance abilities occurs. Thirty subjects randomly divided into two groups performed multistage all-out exertion protocol on cycle-ergometer with measurements of ventilatory-metabolic and subjective parameters of exertion. Each stage lasted three minutes and was followed with three minute breaks during which the subjects underwent the static (keeping the cursor in the center of the screen) and the dynamic balance testing (following the cursor clockwise or counter clock wise by body movements) on balance platform. In a control group, the protocol encompassed only balance testing procedures followed by 3 min rest. After the completion of the testing procedures, the five intensity zones were determined according to the ventilatory-metabolic parameters. The significant differences in both static and dynamic balance tests were found between the test stages in exercising group. The post hoc analyses revealed the significant negative effect of exercise on the static balance with three visible "balance thresholds". The first threshold was at the rest to work transition, the second at the anaerobic threshold and the third at the maximal exertion level. The dynamic balance was also negatively affected with exercise, however no "balance thresholds" were clearly identified. No significant changes in neither static nor dynamic balance abilities were observed in the control group so the changes in the experimental group could have been attributed to the exercise intensity.

Intersession reliability of a posturo-stabilometric test, using a force platform

AIM OF THE STUDY

To evaluate the intersession reliability of a posturo-stabilometric examination.

METHODS

Single blind clinical trial conducted in two sessions over two weeks. 44 healthy volunteers free from postural and temporomandibular disorders. All the subjects complied with the criteria for completing the study. All the subjects underwent two sessions of posturo-stabilometric examinations in different visual and mandibular conditions. Sway area, sway length and the coordinates of the center of pressure were evaluated and statistically analyzed using the Intraclass correlation coefficient (ICC).

RESULTS

All the posturo-stabilometric parameters seemed to have an excellent reproducibility with overall ICCs higher than 70% and good confidence intervals except for the sway area (ICC 0.422 with CI 0.283-0.560 with open eyes and ICC 0.554 with CI 0.424-0.683 with closed eyes).

CONCLUSIONS

The posturo-stabilometric examination carried out using a force platform has a good intrasession and intersession reliability, especially considering sway velocity, COP X and COP Y parameters. The force platform usefulness in analyzing static posture is confirmed in any medical field.

Stepping in persons poststroke: comparison of voluntary and perturbation-induced responses

OBJECTIVES

To examine the stepping performance during voluntary and waist-pull perturbation-induced step initiation in people with chronic stroke.

DESIGN

Repeated-measures single-case design.

SETTING

University-based research laboratory.

PARTICIPANTS

Community-dwelling stroke survivors (N=10).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Ground reaction forces and kinematic data were recorded to assess anticipatory postural adjustments (APAs) and step characteristics for both voluntary and induced stepping conditions.

RESULTS

Induced stepping was performed with both the paretic (35% trials) and nonparetic legs (65% trials). Induced first steps occurred earlier and were executed faster than rapid voluntary steps. Compared with voluntary stepping, induced first step APAs were shorter in duration. Step height was higher with the nonparetic leg for both stepping conditions. Use of the paretic leg increased (52%) during the diagonal perturbations that passively unloaded the stepping limb compared with the use of the paretic leg (33%) for forward perturbations.

CONCLUSIONS

The results indicated differences in executing voluntary and induced stepping, and between the paretic and nonparetic limbs in individuals with chronic stroke. The findings suggested guidelines for using stepping as a component of neurorehabilitation programs for enhancing balance and mobility. Additional larger-scale studies remain to be undertaken to further investigate these issues.

Validity and reliability of the Berg Balance Scale for community-dwelling persons with lower-limb amputation

OBJECTIVE

To evaluate the validity and reliability of the Berg Balance Scale (BBS) for use in people with lower-limb amputation.

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PARTICIPANTS

Individuals (N=30; age, 54±12y; 20 men) with unilateral transtibial (n=13), unilateral transfemoral (n=14), or bilateral (n=3) lower-limb amputation of dysvascular (n=7), traumatic (n=14), infectious (n=6), or congenital (n=3) origin.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

BBS, 2-minute walk test, L test, Prosthesis Evaluation Questionnaire-Mobility Subscale, Activities-specific Balance Confidence Scale, and Frenchay Activities Index; self-reported descriptors were also collected, including frequency of prosthesis use, number of falls in 12 months before the visit, fear of falling, and daily mobility aid use.

RESULTS

The BBS had high interrater reliability (intraclass correlation coefficient =.945) and internal consistency (α=.827). Relations between the BBS scores and those of other outcome measures were all statistically significant (P≤.001). Significant group differences in BBS scores were observed for fear of falling (P=.008) and mobility aid use (P<.001), but not for multiple (≥2) falls in the previous 12 months (P=.381). BBS items involving reaching forward, turning 360°, tandem standing, and standing on 1 leg had relatively greater frequencies of lower scores across participants.

CONCLUSIONS

The BBS appears to be a valid and reliable clinical instrument for assessing balance in individuals with lower-limb amputation, but it may not be able to discriminate between individuals with greater or lesser fall risk. Limitations in prosthetic motion and control may be responsible for the challenges experienced on items of lower performance. Future studies would be useful to assess the responsiveness of the BBS to interventions aimed at improving balance in individuals with lower-limb amputation.

Determinants and consequences for standing balance of spontaneous weight-bearing on the paretic side among individuals with chronic stroke

Hemiparetic stroke patients commonly bear more weight on the non-paretic side which seems intuitively linked to unilateral control deficits. However, there is evidence that some post-stroke favour weighting the paretic side, which may be problematic given altered capacity of the paretic limb to contribute to the control of upright posture. This study explores the prevalence and clinical determinants of stance asymmetry, and the relationship between stance asymmetry and postural control among chronic stroke patients. Subjects (n=147; >6 months post-stroke) stood on two force plates in eyes-open and eyes-closed conditions; 59 were symmetric, 18 had paretic asymmetry (PA), and 70 had non-paretic asymmetry (NPA). Root mean square (RMS) of antero-posterior and medio-lateral centre-of-pressure under each limb and both limbs combined were compared. RMS of total medio-lateral centre-of-pressure was greater for both asymmetric groups compared with the symmetric group. PA subjects relied less on the loaded limb for control than NPA subjects and relied more on visual information for postural control than those who were symmetric. There were no differences in the characteristics of individuals between the PA and NPA groups. The loading of the paretic limb was not related to impaired postural control during stationary standing which was attributable, in part, to individuals relying on control from the non-paretic limb, in spite of lower vertical load, and a greater dependence on visual contributions. There was no evidence that greater loading on the paretic limb was related to persisting dyscontrol but may rather reflect a learned strategy.

Sequential analysis of postural control resource allocation during a dual task test

OBJECTIVE

To investigate the postural control factors influencing the automatic (reflex-controlled) and attentional (high cortical) factors on dual task.

METHODS

We used a dual task model to examine the attentional factors affecting the control of posture, subjecting test subjects to vibration stimulation, one-leg standing and verbal or nonverbal task trials. Twenty-three young, healthy participants were asked to stand on force plates and their centers of pressure were measured during dual task trials. We acquired 15 seconds of data for each volunteer during six dual task trials involving varying task combinations.

RESULTS

We observed significantly different sway patterns between the early and late phases of dual task trials, which probably reflect the attentional demands. Vibration stimulation perturbed sway more during the early than the late phases; with or without vibration stimulation, the addition of secondary tasks decreased sway in all phases, and greater decreases in sway were observed in the late phases, when subjects were assigned nonverbal tasks. Less sway was observed during the nonverbal task in a sequential study.

CONCLUSION

The attentional and automatic factors were analyzed during a sequential study. By controlling the postural control factors, optimal parameters and training methods might be used in clinical applications.

Evaluation of the association between osteoporosis and postural balance in postmenopausal women

The incidence of osteoporosis has been increasing, as have fractures resulting from falls. Postural balance was evaluated in postmenopausal women with and without lumbar osteoporosis. One hundred and twenty-six postmenopausal women aged 55-65 years were evaluated and separated into two groups according to the bone mineral density values of their lumbar spine: the osteoporosis group and the control group, paired by age (P = 0.219) and physical activity (P = 0.611). There was no difference between the groups (P = 0.139) regarding falls reported in the previous 12 months. Functional mobility was evaluated through the Timed Up and Go Test. Postural balance was evaluated using a portable force platform in standard standing position, with eyes open and closed, for 60s. Muscle strength was evaluated through an isokinetic dynamometer. This study shows that there is no difference in knee muscle strength and functional mobility (P = 0.121), postural balance with eyes open [mediolateral displacement (P = 0.286) and mean velocity of the center of pressure (COP) (P = 0.173)] and with eyes closed [mediolateral displacement (P = 0.163), and the mean velocity of displacement of the COP (P = 0.09)] in both groups. Subjects reporting falls had greater mediolateral displacement (P = 0.028) in both groups. Postmenopausal women aged between 55 and 65 years do not present changes in postural balance irrespective of lumbar osteoporosis. Greater COP mediolateral displacement is related to the occurrence of falls in postmenopausal women in the previous year.

Does calf muscle spasticity contribute to postural imbalance? A study in persons with pure hereditary spastic paraparesis

OBJECTIVES

The contribution of spasticity to postural imbalance in patients with upper motor neuron syndrome is still unclear. This study aimed to evaluate the responses to support-surface perturbations in patients with hereditary spastic paraparesis (HSP). These patients typically suffer from bilateral spasticity with relatively preserved muscle strength of the lower limbs. Particularly toes-up rotations were expected to be destabilizing due to insufficient suppression of calf muscle stretch reflexes.

METHODS

Participants were seventeen symptomatic community-dwelling patients with autosomal dominant pure HSP and seventeen healthy controls. All patients had increased muscle tone of the triceps surae (TS) but no muscle contractures. Perturbations were applied by rotating or translating a platform with increasing intensity in four sagittal-plane directions. The primary outcome was maximum intensity ('limit of stability') sustained without stepping or grabbing in each type of perturbation. Leg muscle tone and strength were assessed with the Modified Ashworth Scale and Medical Research Council (MRC) scale, respectively.

RESULTS

For toes-up perturbations, limits of stability in patients were substantially lower than in controls, which were related to TS muscle tone but not to tibialis anterior (TA) strength. Toes-down rotations were indiscriminative. For backward perturbations, patients also had lower limits of stability, unrelated to TA strength or TS muscle tone. In forward perturbations, patients with TS strength MRC 4 were less stable than patients with normal TS strength and controls.

CONCLUSION

Calf muscle spasticity and weakness differently contribute to postural imbalance in patients with HSP. This notion could have implications for the clinical management of spasticity.

Influence of visual inputs on quasi-static standing postural steadiness in individuals with spinal cord injury

Postural steadiness while standing is impaired in individuals with spinal cord injury (SCI) and could be potentially associated with increased reliance on visual inputs. The purpose of this study was to compare individuals with SCI and able-bodied participants on their use of visual inputs to maintain standing postural steadiness. Another aim was to quantify the association between visual contribution to achieve postural steadiness and a clinical balance scale. Individuals with SCI (n = 15) and able-bodied controls (n = 14) performed quasi-static stance, with eyes open or closed, on force plates for two 45 s trials. Measurements of the centre of pressure (COP) included the mean value of the root mean square (RMS), mean COP velocity (MV) and COP sway area (SA). Individuals with SCI were also evaluated with the Mini-Balance Evaluation Systems Test (Mini BESTest), a clinical outcome measure of postural steadiness. Individuals with SCI were significantly less stable than able-bodied controls in both conditions. The Romberg ratios (eyes open/eyes closed) for COP MV and SA were significantly higher for individuals with SCI, indicating a higher contribution of visual inputs for postural steadiness in that population. Romberg ratios for RMS and SA were significantly associated with the Mini-BESTest. This study highlights the contribution of visual inputs in individuals with SCI when maintaining quasi-static standing posture.

Dual-task effect on gait balance control in adolescents with concussion

OBJECTIVE

To prospectively and longitudinally examine how concussion affects gait balance control in adolescents during single- and dual-task walking.

DESIGN

Cohort, prospective, repeated-measures design.

SETTING

Motion analysis laboratory.

PARTICIPANTS

Adolescents (N=20) identified as suffering a concussion were matched with healthy control subjects (N=20) and tested 5 times across a 2-month period after injury.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Gait temporal-distance parameters included average walking speed, step length, and step width; whole body center of mass (COM) parameters included medial/lateral displacement and peak COM medial/lateral and anterior velocities; dual-task cost, which was defined as percent change from single- to dual-task conditions; and Stroop test accuracy.

RESULTS

No between-group differences were observed for step length and step width. The dual-task cost for average walking speed for subjects with concussion was greater than control subjects across the 2-month testing period (main effect of group P=.019), as was the dual-task costs for peak anterior COM velocity (main effect of group P=.017) and total COM medial/lateral displacement (main effect of group P=.013). The total COM medial/lateral displacement (group × task interaction P=.006) and peak COM medial/lateral velocity (main effect of group P=.027; main effect of task P=.01) were significantly greater in subjects with concussion compared with control subjects during dual-task walking. Subjects with concussion were significantly less accurate than controls on the Stroop test (main effect of group P=.004).

CONCLUSIONS

The findings suggest that concussion affects the ability of adolescents to control body posture during gait up to 2 months after injury. Furthermore, dual-task paradigms may provide additional useful information in the clinical assessment and recovery of concussion.

The sitting-unsupported balance score as an early predictor of functional prognosis in stroke patients: a pilot study

OBJECTIVE

To evaluate the impact of initial "sitting-unsupported" Berg Balance Scale (SUB), the specific trunk control parameter, on patients' functional outcome, Korean version of Modified Barthel Index (K-MBI) at 6 months.

METHODS

The charts of 30 patients retrospectively reviewed reviewed. The initial Korean version of Berg Balance Scale (K-BBS) including SUB along with patients' Korean version of Mini-Mental State Examination (K-MMSE), Glasgow Coma Scale (GCS), and other functional parameters that affect functional outcome were recorded. Cases were divided into low (group I) and high (group II) initial SUB score groups. Correlation and regression analysis were performed to assess the relationship between the initial SUB on the K-MBI at 6 months.

RESULTS

The mean±standard deviation score of initial SUB/K-MBI at 6 months of groups I and II were 0.056±0.236/26.89±32.48, 3.58±0.515/80.25±18.78, respectively, and showed statistical significant differences to each other (p<0.05). K-MBI at 6 months was highly correlated with initial GCS, SUB, K-BBS, K-MMSE, and initial K-MBI (p<0.05). In multiple linear regression analysis, initial SUB and GCS scores remained significantly associated with K-MBI at 6 months. A logistic regression model revealed that initial SUB (p=0.004, odds ratio=16), initial K-MBI, GCS, and K-MMSE were all significant predictors of K-MBI scores at 6 months.

CONCLUSION

Initial SUB scores could be helpful in predicting patient's potential functional recovery at 6 months. Further studies with concurrent controls and a larger sample group are required to fully establish this tool.

Postural control and fear of falling assessment in people with chronic obstructive pulmonary disease: a systematic review of instruments, international classification of functioning, disability and health linkage, and measurement properties

OBJECTIVES

To systematically review the instruments used to assess postural control and fear of falling in people with chronic obstructive pulmonary disease (COPD), and to synthesize and evaluate their breadth of content and measurement properties.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, CINAHL, CENTRAL, PsycINFO, PEDro, and OTSeeker databases searched in September 2012.

STUDY SELECTION

Two independent reviewers performed the selection of articles, the ICF linking process and quality assessment. Only quantitative studies were included, irrespective of language or publication date.

DATA EXTRACTION

This systematic review comprised two phases. Phase 1 aimed to identify the commonly used instruments to assess postural control and fear of falling in the COPD literature. The breadth of content of each instrument was examined based on the International Classification of Functioning, Disability and Health (ICF). In phase 2, a measurement property search filter was adopted and used in four electronic databases to retrieve properties reported in the COPD population. The COSMIN checklist was used to assess the methodological quality of each measurement property reported.

DATA SYNTHESIS

Seventeen out of 401 publications were eligible in phase 1. Seventeen instruments were identified including 15 for postural control and 2 for fear of falling assessment. The Berg Balance Scale, the Short Physical Performance Battery, and the Activities-specific Balance Confidence (ABC) scale were the most frequently used instruments to assess postural control and fear of falling respectively. The ICF categories covered varied considerably among instruments. The Balance Evaluation Systems test and ABC presented the greatest breadth of content. Measurement properties reported included criterion predictive validity (4 instruments), construct validity (11 instruments) and responsiveness (1 instrument), with inconsistent findings based on 'fair' and 'poor' quality studies.

CONCLUSIONS

Different instruments with heterogeneous content have been used to assess postural control and fear of falling outcomes. Standardized assessment methods and best evidence on measurement properties is required in the COPD literature.

The effect of the forward head posture on postural balance in long time computer based worker

Objective

To estimate the effects of a relatively protruded head and neck posture on postural balance, in computer based worker.

Method

Thirty participants, who work with computers for over 6 hrs per day (Group I), and thirty participants, who rarely work with computers (Group II), were enrolled. The head and neck posture was measured by estimating angles A and B. A being the angle between the tragus of the ear, the lateral canthus of the eye, and horizontal line and B the angle between the C7 spinous process, the tragus of the ear, and the horizontal line. The severity of head protrusion with neck extension was assessed by the subtraction of angle A from angle B. We also measured the center of gravity (COG) and postural balance by using computerized dynamic posturography to determine the effect of computer-based work on postural balance.

Results

Results indicated that group I had a relatively more protruded head with extensive neck posture (angle B-A of group I and group II, 28.2±8.3, 32.9±6.0; p<.05). The COG of group I tended more toward the anterior than that of group II. Postural imbalance and impaired ability to regulate movement in forward and backward direction were also found.

Conclusion

The results of this study suggest that forward head postures during computer-based work may contribute to some disturbance in the balance of healthy adults. These results could be applied to education programs regarding correct postures when working at a computer for extended periods of time.

The effects of anxiety on balance parameters in young female university students

OBJECTIVE

In human beings, the balance control is a result of an integration of physical and psychological factors and people show different reactions when feel anxious or face stability threatened conditions such as standing on an unstable surface. University students, particularly the female ones, are a group of the society who are prone to face anxieties. The current study focused on the effects of anxiety on balance index in young female university students.

METHODS

A group of 15 female students with a high anxiety score (higher than 42 in Shpielberger Questionnaire) and a group of 15 female students with a low anxiety score (lower than 42 in Shpielberger Questionnaire) were recruited for this study. Using a Biodex stabilometer (Biodex System, USA), the antero-posterior (AP), medio-latral (ML) and the overall dynamic stability index (SI) of the subjects were recorded and compared.

RESULTS

The results revealed a significant difference between the two groups. Subjects with a high anxiety score showed a stability index higher than those in the low anxiety group (p<0.005), which simply indicate significantly less stability in this group.

CONCLUSION

This study showed that subjects with higher anxiety scores were less stable compared to those subjects with lower anxiety scores.