Balance in single-limb stance in healthy subjects--reliability of testing procedure and the effect of short-duration sub-maximal cycling

Normalized stability time analysis within the boundaries between adults with and without fear of falling

BACKGROUND

The unilateral stance test, measured by the center of pressure (COP), has been widely used to identify balance deficits. However, there is a critical gap in understanding the specific COP thresholds on postural stability in adults with a fear of falling (FOF).

AIMS

To investigate the normalized stability time, which was defined as the ratio of time spent within stability boundaries to the total test duration, under different visual conditions and specific thresholds between adults with and without FOF.

METHODS

Twenty-one older adults with FOF and 22 control subjects completed the unilateral limb standing test in eyes-open and eyes-closed conditions. Normalized stability times were computed based on five pre-determined COP sway range thresholds: 10 mm, 15 mm, 20 mm, 25 mm, and 30 mm.

RESULTS

Receiver operating characteristic analysis determined the diagnostic accuracy of FOF. There were significant differences in the effects of both visual conditions (F = 46.88, p = 0.001) and threshold settings (F = 119.38, p = 0.001) on stability time between groups. The FOF group significantly reduced normalized stability time at the 10 mm COP threshold under eyes-closed conditions (t = - 1.95, p = 0.03).

DISCUSSION

The findings highlight the heightened sensitivity of the 10 mm COP threshold in identifying group variances in postural stability when eyes are closed. Moreover, the FOF group displayed a marked reduction in stability duration based on visual scenarios and normalized thresholds.

CONCLUSION

The study highlights the need to account for both COP boundaries and visual conditions in adults with FOF. When assessing postural control during unilateral stances, clinicians must also give attention to non-visual cues.

Effects of Virtual Reality on Transtibial Amputation Rehabilitation Outcomes: A Randomized Study

Purpose: Virtual reality is widely used in patients with chronic musculoskeletal problems. However, the short-term effects on individuals with transtibial (TT) amputation during this process remain unclear. This study aimed at investigating the effects of virtual reality on rehabilitation outcomes in TT amputees. Methods: The study included 20 TT amputees who were using TT prostheses. The participants were divided into two groups randomly as follows: physiotherapy (PT) and virtual reality (VR). Participants were treated 3 days a week, for 4 weeks, and evaluations were made before and after treatment; a 6-minute walk test was used for performance, a single-leg balance test for balance, Trinity Amputation Prosthesis Experience Scale for prosthesis satisfaction, a 10-meter walking test for gait speed, and a wearable smart t-shirt to determine cadence. Results: It was found that there was a statistically significant difference in performance, balance, prosthesis satisfaction, cadence, and gait speed before and after PT (P < 0.05). There were differences in terms of performance, prosthesis satisfaction, balance, cadence, and gait speed before and after VR (P < 0.05). There was no statistically significant difference between PT and VR (P > 0.05). Conclusion: The 4 weeks of VR training improved performance, prosthesis satisfaction, balance, cadence, and gait speed in TT amputation rehabilitation similar to physiotherapy methods. The addition of VR training to amputation rehabilitation will bring improvements since it is a fun and safe intervention. Clinical Trial Registration: The trial is registered at Clinical Trials.gov, Trial No: NCT03872193.

Physical activity, balance, and bicycling in older adults

Falls are a critical public health issue among older adults. One notable factor contributing to falls in older adults is a deterioration of the structures supporting balance and overall balance control. Preliminary evidence suggests older adults who ride a bicycle have better balance than those who do not. Cycling may be an effective intervention to prevent falls among older adults. This study aims to objectively measure the relationship between bicycling, physical activity, and balance for older adults. Older adult cyclists (n = 19) and non-cyclists (n = 27) were recruited to (1) complete a survey that assessed demographics; (2) wear an accelerometer for 3 weeks to objectively assess physical activity; and (3) complete balance-related tasks on force platforms. Mann-Whitney U-tests were performed to detect differences in balance and physical activity metrics between cyclists and non-cyclists. Cyclists were significantly more physically active than non-cyclists. Cyclists, compared to non-cyclists, exhibited differences in balance-related temporospatial metrics and long-range temporal correlations that suggest a more tightly regulated postural control strategy that may relate to higher stability. Cycling was observed to correlate more strongly with balance outcomes than other physical activity. Taken together, these results demonstrate the possible implications for cycling as an effective intervention to improve balance and reduce fall risk.

Effects of exercise on balance in patients with non-specific low back pain: a systematic review and meta-analysis

INTRODUCTION

Non-specific low back pain (NS-LBP) is one of the most common musculoskeletal conditions related to medical expenses and disability. Evidence suggests that changes in motion patterns could induce trunk instability and impaired postural control. Therefore, this systematic review investigated the effects of exercise on balance in patients with NS-LBP.

EVIDENCE ACQUISITION

A systematic review and meta-analysis were conducted. Findings were reported following the 2020 PRISMA statement and the main databases were searched for RCTs. Studies were independently screened through a standardized form and their internal validity assessed by using the Cochrane risk of bias (RoB) tool. Pooled effects were calculated at post-treatment and quality of evidence was assessed through the GRADE framework.

EVIDENCE SYNTHESIS

Twelve articles were included in the review, eight in the meta-analysis. None of the studies were judged at low RoB. There is very low-quality evidence that exercise is effective in reducing Centre of Pressure (CoP) displacement (-16.99 [-27.29, -6.68]; P=0.001) and in improving single-leg stance test performance (-28.7 [-48.84, -8.67]; P=0.005) and dynamic balance (-4.74 [-8.02, -1.46]; P=0.005). Conversely, no significant results were observed in "ellipse area" and in "limits of stability" indexes. Other results were summarized in a qualitative synthesis.

CONCLUSIONS

Exercise could be effective in improving both static and dynamic balance in patients with NS-LBP over a short-term period. However, quality of evidence was estimated as very low, hence further double-blinded, high-quality RCTs are needed to address clinical practice and research.

Quantitative assessment of postural balance in patients with chronic anterior cruciate ligament injury- A controlled study

PURPOSE

Evaluation of single and double limb support postural balance in patients with Anterior cruciate ligament (ACL)injury and comparison of the postural strategy adopted after ACL injury/deficiency(ACLD) with that of an age-matched healthy individual.

METHODS

The study group that included 33 subjects confirming inclusion criteria had undergone postural balance assessment using the HUMAC Balance system. The parameters of the center of pressure excursion were recorded on a force plate and compared with age, BMI matched 66 healthy volunteers of control group. The center of pressure excursions was monitored using dependable variables such as sway path length(cm), the average velocity of sway(cm/sec), and the mean COP stability score(%). The mobility component was recorded as the percentage (%) of time spent on each target.

RESULT

A decrease in postural balance in the injury group was evidenced by a statistically significant decrease of stability score(p = 0.015), increase in path length(p = 0.002) and decrease on time on target mean score (p= <0.001),. Although, the stability score path length and average sway velocity scores in the sound limb of the ACLD group showed impaired balance, the differences were not statistically significant (p = 0.180, p = 0.561, and p = 0.639 respectively) when compared with the dominant limb of the control group.

CONCLUSION

HUMAC balance system is an effective and simplified measure for quantifying postural balance. Although overall postural stability in ACL injury is impaired, static postural balance is maintained by the compensatory of strategy of sound limb. However, the quantitative parameters of postural stability for the sound limb, despite of a lower mean value, did not show statistically significant differences from the dominant limb of the controlled group.

Does kinesiotaping can improve static stability of the knee after anterior cruciate ligament rupture? A randomized single-blind, placebo-controlled trial

Background

The aim of the study was the assessment of the early impact of the selected kinesiotaping technique on the static stability of the knee joint in patients with ACL rupture on the basis of stabilographic parameters.

Methods

Sixty-two patients with a complete ACL rupture (32 patients in experimental group and 30 patients in placebo group) took part in the randomized single-blind, placebo-controlled trial. The ligament technique of KT was taken into consideration. Application of a KT tape only on the injured knee was to stabilize the knee joint. Experimental group had application of KT on the injured knee and the placebo group had a KT placebo application (with no tension on KT). Intervention and stabilographic test in both groups was the same.

Research tools included measurements of static stabilographic parameters on stabilometric platform CQStab2P®. Outcome measures were assessed before intervention and after KT application. The analysis included evaluation of outcome variables – total path length, (SP), statokinesiogram path length in the XY axes (SPML, SPAP), and mean velocities in the XY axes (MV, MVML, MVAP).

Results

The results show a statistically significant shortening of the SP, SPAP and SPML variables only in experimental group. In the placebo group the results were not significant. The analysis also showed a significant improvement in all analyzed variables in the experimental group compared to the healthy side. In the placebo group, the results did not improve significantly after KT application compared to the healthy side.

Conclusions

Application o

f KT in patients after ACL rupture shortened the total path length and improved the value of parameters in the frontal and sagittal planes in experimental group, which may suggest the potentially greater improvement in these parameters. By improving the values of the analyzed variables, the KT application is able to compensate for the loss of static stability of the knee.

Trial Registration

This study was registered retrospectively in the Australian New Zealand Clinical Trials Registry (ANZCTR). Registration number: ACTRN12616001407482.

Lower Extremity Open Skill Training Effects on Perception of Visual Stimuli, Cognitive Processing, and Performance

This study investigates if lower extremity open-skill training impacts perception and cognitive processing abilities or just influences task related motor abilities. Twenty-two participants (24.7 ± 2.4years; 11 males, 11 females) were randomly allocated either into the group that trained on a computerized device or to the control group. Prior to and following the 4-week study period, motor performance was assessed using drop jump, hexagon test, postural control and lower extremity choice reaction. Perception, cognitive processing and task inhibition were captured using validated neurocognitive tests. Repeated measurements analyses of co-variances (ANCOVAs) were performed. They revealed a time (before and after intervention) × group (training vs. control) effect on lower extremity choice reaction and hexagon (p < .05). No effects on group differences or between groups in cognitive performance were found. A detrimental effect of training on accuracy of task inhibition (lower percentage of correct inhibitions) was detected. Computerized open skill training affects specific movement patterns without increasing task-relevant cognitive or perceptual abilities. Indicated by the lower percentage of correct inhibitions, the training might further detrimentally influence the risk-taking behavior during choice reaction tasks.

The Effectiveness of Virtual Reality in Patients With Spinal Pain: A Systematic Review and Meta-Analysis

BACKGROUND

Virtual reality (VR) technologies have been shown to be beneficial in various areas of health care; to date, there are no systematic reviews examining the effectiveness of VR technology for the treatment of spinal pain.

PURPOSE

To investigate the effectiveness of VR technology in the management of individuals with acute, subacute, and chronic spinal pain.

METHODS

Six electronic databases were searched until November 2019. Randomized controlled trials (RCTs) assessing the effectiveness of VR were eligible for inclusion. Two independent reviewers extracted the data and assessed the risk of bias for each study and the overall quality of evidence. Mean differences of outcomes were pooled as appropriate using random-effects models.

RESULTS

Seven RCTs with high risk of bias met review criteria. Quality of evidence ranged from very low to low quality. In patients with chronic neck pain, VR improved global perceived effect (GPE), satisfaction, and general health at short-term follow-up, as well as general health and balance at intermediate-term follow-up compared to kinematic training. VR improved pain intensity and disability at short-term and long-term follow-up compared to conventional proprioceptive training in patients with chronic neck pain. In patients with either subacute or chronic low back pain (LBP), VR improved pain, disability, and fear of movement compared to lumbar stabilization exercises and improved pain compared to conventional physical therapy (at short-term follow-up). In patients with chronic LBP, VR improved pain compared to lumbar stabilization exercises and improved fear of movement compared to conventional physical therapy (at short-term follow-up).

CONCLUSION

VR's potential for improvement in outcomes for spinal pain that demonstrated statistical and/or clinical significance (pain intensity, disability, fear of movement, GPE, patient satisfaction, general health status, and balance) highlights the need for more focused, higher-quality research on the efficacy and effectiveness of VR for treatment of patients with spinal pain.

The Characteristics of Feet Center of Pressure Trajectory during Quiet Standing

To investigate the level of bilateral symmetry or asymmetry between right and left foot center of pressure (COP) trajectory in the mediolateral and anteroposterior directions, this study involved 102 participants (54 females and 48 males). Ground reaction forces were measured using two Kistler force plates during two 45-s quiet standing trials. Comparisons of COP trajectory were performed by correlation and scatter plot analysis. Strong and very strong positive correlations (from 0.6 to 1.0) were observed between right and left foot anteroposterior COP displacement trajectory in 91 participants; 11 individuals presented weak or negative correlations. In the mediolateral direction, moderate and strong negative correlations (from −0.5 to −1.0) were observed in 69 participants, weak negative or weak positive correlations in 30 individuals, and three showed strong positive correlations (0.6 to 1.0). Additional investigation is warranted to compare COP trajectories between asymptotic individuals as assessed herein (to determine normative data) and those with foot or leg symptoms to better understand the causes of COP asymmetry and aid clinicians with the diagnosis of posture-related pathologies.

Effect of quadriceps and calf muscles fatigue on standing balance in healthy young adult males

OBJECTIVE

The present study aimed to compare the effects of quadriceps or calf muscles fatigue on static and dynamic standing balance in young healthy adult males.

METHODS

Forty-five healthy, physically active male adults aged 18-30 years were randomly divided into three groups; Quadriceps muscle fatigue group (n=15), Calf muscles fatigue group (n=15), and a control group (n=15). The Modified Clinical Test of Sensory Interaction on Balance, Unilateral Stance, and Limits of Stability (reaction time and movement velocity) were selected as outcome measures for this study.

RESULTS

The results showed a non-significant difference between pretest and posttest balance scores (p>0.05) for quadriceps and calf muscles fatigue on balance. Similarly, there were non-significant differences in posttest balance scores when comparing fatigue effects between the groups (p>0.05).

CONCLUSIONS

These results suggested that the fatigue of the quadriceps or calf muscles did not influence standing balance in healthy young adult males. Future longitudinal studies are recommended to further understanding the mechanisms behind localized muscle fatigue effects on standing balance in subjects of different age groups of both genders.

Effect of footwear on standing balance in healthy young adult males

OBJECTIVE

The present study aimed to evaluate the effect of footwear on standing balance in healthy young adult males.

METHODS

Thirty healthy male participants aged 20-30 years were tested for standing balance on the Balance Master on three occasions, including wearing a sandal, standard shoe, or no footwear (barefoot). The tests of postural stability include; "Modified Clinical Test of Sensory Interaction on Balance" (mCTSIB), "Unilateral Stance" (US), and the "Limits of Stability" (LOS). The balance scores (mCTSIB, US, and LOS) was analyzed.

RESULTS

There was a significant effect between footwear conditions for mCTIB with eye closed on a firm surface (p=0.002). There was a significant effect between footwear conditions for the US with eye open and closed (p⟨0.05). There was a significant effect between footwear conditions for LOS reaction time during forward movement (p=0.02). Similarly, there was a significant effect between footwear conditions for LOS reaction time during left side movement (p=0.01).

CONCLUSIONS

Wearing sandals compared to bare feet significantly increased postural sway and reduced stability in healthy young adult males. However, wearing a standard shoe compared to bare feet did not significantly affect balance scores in standing.

Test-retest reliability of a balance testing protocol with external perturbations in young healthy adults

External perturbations are utilized to challenge balance and mimic realistic balance threats in patient populations. The reliability of such protocols has not been established. The purpose was to examine test-retest reliability of balance testing with external perturbations. Healthy adults (n=34; mean age 23 years) underwent balance testing over two visits. Participants completed ten balance conditions in which the following parameters were combined: perturbation or non-perturbation, single or double leg, and eyes open or closed. Three trials were collected for each condition. Data were collected on a force plate and external perturbations were applied by translating the plate. Force plate center of pressure (CoP) data were summarized using 13 different CoP measures. Test-retest reliability was examined using intraclass correlation coefficients (ICC) and Bland-Altman plots. CoP measures of total speed and excursion in both anterior-posterior and medial-lateral directions generally had acceptable ICC values for perturbation conditions (ICC=0.46 to 0.87); however, many other CoP measures (e.g. range, area of ellipse) had unacceptable test-retest reliability (ICC<0.70). Improved CoP measures were present on the second visit indicating a potential learning effect. Non-perturbation conditions generally produced more reliable CoP measures than perturbation conditions during double leg standing, but not single leg standing. Therefore, changes to balance testing protocols that include external perturbations should be made to improve test-retest reliability and diminish learning including more extensive participant training and increasing the number of trials. CoP measures that consider all data points (e.g. total speed) are more reliable than those that only consider a few data points.

Effect of quadriceps and hamstrings muscle cooling on standing balance in healthy young men

OBJECTIVE

The present study compared the effect of quadriceps and hamstring muscle cooling on standing balance in healthy young men.

METHODS

Thirty healthy young men (18-30 years) participated in the study. The participants were randomly assigned to three groups (n=10 each): quadriceps cooling (QC), hamstring cooling (HC), or control group (no cooling). Participants in the QC and HC groups received 20 minutes of cooling using a cold pack (gel pack), placed on the anterior thigh (from the apex of the patella to the mid-thigh) and the posterior thigh (from the base of the popliteal fossa to the mid-thigh), respectively. Balance score including unilateral stance was measured at baseline and immediately after the application of the cold pack.

RESULTS

No significant difference in the balance score was noted in any group after the application of the cold pack (p⟩0.05). Similarly, no significant differences in post-test balance score were noted among the three groups (p⟩0.05).

CONCLUSIONS

Cooling of the quadriceps and hamstring muscles has no immediate effect on standing balance in healthy young men. However, longitudinal studies are warranted to investigate the long-term effects of cooling these muscles on standing balance.

Objective impairments of gait and balance in adults living with HIV-1 infection: a systematic review and meta-analysis of observational studies

BACKGROUND

Gait and balance deficits are reported in adults with HIV infection and are associated with reduced quality of life. Current research suggests an increased fall-incidence in this population, with fall rates among middle-aged adults with HIV approximating that in seronegative elderly populations. Gait and postural balance rely on a complex interaction of the motor system, sensory control, and cognitive function. However, due to disease progression and complications related to ongoing inflammation, these systems may be compromised in people with HIV. Consequently, locomotor impairments may result that can contribute to higher-than-expected fall rates. The aim of this review was to synthesize the evidence regarding objective gait and balance impairments in adults with HIV, and to emphasize those which could contribute to increased fall risk.

METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. An electronic search of published observational studies was conducted in March 2016. Methodological quality was assessed using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Narrative synthesis of gait and balance outcomes was performed, and meta-analyses where possible.

RESULTS

Seventeen studies were included, with fair to low methodological quality. All studies used clinical tests for gait-assessment. Gait outcomes assessed were speed, initiation-time and cadence. No studies assessed kinetics or kinematics. Balance was assessed using both instrumented and clinical tests. Outcomes were mainly related to center of pressure, postural reflex latencies, and timed clinical tests. There is some agreement that adults with HIV walk slower and have increased center of pressure excursions and -long loop postural reflex latencies, particularly under challenging conditions.

CONCLUSIONS

Gait and balance impairments exist in people with HIV, resembling fall-associated parameters in the elderly. Impairments are more pronounced during challenging conditions, might be associated with disease severity, are not influenced by antiretroviral therapy, and might not be associated with peripheral neuropathy. Results should be interpreted cautiously due to overall poor methodological quality and heterogeneity. Locomotor impairments in adults with HIV are currently insufficiently quantified. Future research involving more methodological uniformity is warranted to better understand such impairments and to inform clinical decision-making, including fall-prevention strategies, in this population.

Results of a Pilates exercise program in patients with chronic non-specific low back pain: a randomized controlled trial

OBJECTIVE

To investigate the effects of a Pilates exercise program on disability, pain, lumbar mobility, flexibility and balance in patients with chronic non-specific low back pain.

DESIGN

Randomized controlled trial.

SETTING

University laboratory.

PARTICIPANTS

A total of 54 patients with chronic non-specific low back pain.

INTERVENTION

Patients were randomly allocated to an experimental group ( n=27) included in a Pilates exercise program or to a control group ( n=27) receiving information in a form of a leaflet.

MAIN OUTCOME MEASURES

Disability (Roland-Morris Disability Questionnaire and Oswestry Disability Index), current, average and pain at it least and at its worst (Visual Analogue Scales), lumbar mobility (modified Shober test), flexibility (finger-to-floor test) and balance (single limb stance test) were measured at baseline and after the intervention.

RESULTS

A between-group analysis showed significant differences in the intervention group compared to the control group for both disability scores, the Rolland-Morris questionnaire (mean change±standard deviation of 5.31±3.37 and 2.40±6.78 respectively and between-groups mean difference of 3.2 ± 4.12, p=0.003) and the Oswestry Disability Index ( p<0.001), current pain ( p=0.002) and pain at it least ( p=0.033), flexibility (0.032) and balance (0.043).

CONCLUSIONS

An 8-week Pilates exercise program is effective in improving disability, pain, flexibility and balance in patients with chronic non-specific low back pain.

Reliability of System Identification Techniques to Assess Standing Balance in Healthy Elderly

Objectives

System identification techniques have the potential to assess the contribution of the underlying systems involved in standing balance by applying well-known disturbances. We investigated the reliability of standing balance parameters obtained with multivariate closed loop system identification techniques.

Methods

In twelve healthy elderly balance tests were performed twice a day during three days. Body sway was measured during two minutes of standing with eyes closed and the Balance test Room (BalRoom) was used to apply four disturbances simultaneously: two sensory disturbances, to the proprioceptive and the visual system, and two mechanical disturbances applied at the leg and trunk segment. Using system identification techniques, sensitivity functions of the sensory disturbances and the neuromuscular controller were estimated. Based on the generalizability theory (G theory), systematic errors and sources of variability were assessed using linear mixed models and reliability was assessed by computing indexes of dependability (ID), standard error of measurement (SEM) and minimal detectable change (MDC).

Results

A systematic error was found between the first and second trial in the sensitivity functions. No systematic error was found in the neuromuscular controller and body sway. The reliability of 15 of 25 parameters and body sway were moderate to excellent when the results of two trials on three days were averaged. To reach an excellent reliability on one day in 7 out of 25 parameters, it was predicted that at least seven trials must be averaged.

Conclusion

This study shows that system identification techniques are a promising method to assess the underlying systems involved in standing balance in elderly. However, most of the parameters do not appear to be reliable unless a large number of trials are collected across multiple days. To reach an excellent reliability in one third of the parameters, a training session for participants is needed and at least seven trials of two minutes must be performed on one day.

Impaired postural control in healthy men at moderate altitude (1630 m and 2590 m): data from a randomized trial

Objectives

Intact postural control is essential for safe performance of mountain sports, operation of machinery at altitude, and for piloting airplanes. We tested whether exposure to hypobaric hypoxia at moderate altitude impairs the static postural control of healthy subjects.

Methods

In 51 healthy men, median age 24 y (quartiles 20;28), static control was evaluated on a balance platform in Zurich, 490 m, and during a 4-day sojourn in Swiss mountain villages at 1630 m and 2590 m, 2 days each. The order of altitude exposure was randomized. Total center of pressure path length (COPL) and sway amplitude measured in two directions by a balance platform, and pulse oximetry were recorded. Data were compared between altitudes.

Results

Median (quartiles) COPL during standing on both legs with eyes open at 490 m and in the evenings on the first and second days at 1630 and 2590 m, respectively were: 50 (45;57), 55 (48;62), 56 (49;61), 53 (47;59), 54 (48;60) cm, P<0.001 ANOVA. Corresponding arterial oxygen saturation was 97% (96;97), 95% (94;96), 95%(94;96), 92%(90;93), 93%(91;93), P<0.001. Anterior-posterior sway amplitudes were larger at 1630 and 2590 m compared to 490 m, P<0.001. Multiple logistic regression analysis confirmed that higher altitudes (1630 and 2590m) were independently associated with increased COPL when controlled for the order of altitude exposure and age (P=0.001).

Conclusions

Exposure to 1630 and 2590m was associated with impaired static postural control even when visual references were available.

Trial Registration

ClinicalTrials.gov NCT01130948.

Reliability of Single-leg and Double-leg Balance Tests in Subjects with Anterior Cruciate Ligament Reconstruction and Controls

The purpose of this study was to assess the test-retest reliability of postural balance in patients with anterior cruciate ligament reconstruction (ACL) and controls. Ten healthy subjects and 15 individuals with ACL reconstruction performed single-leg and double-leg balance tests. The center of pressure (COP) was recorded using a pressure platform. For the total COP path, the intraclass correlation coefficient (ICC) ranged from 0.79 to 0.91. For the COP standard deviation, the ICCs ranged from 0.68 to 0.94. For the COP velocity, the ICCs ranged from 0.72 to 0.91. The sway area and ellipse scores displayed ICCs values of 0.67 to 0.95 and 0.53 to 0.92, respectively. The ICCs were higher for double leg tests compared with single-stance ones. These results indicate that 30 s balance tests in double and single-leg stance are reliable tools to assess static balance. The use of such tests to monitor rehabilitation programs following ACL reconstruction is recommended.

Control of posture during tasks representing common work-related postures - a reliability study

Assessment of control of posture using a task battery that represents work-related postural conditions is highly recommended for providing a comprehensive understanding of collective postural demands. However, dearth of evidence exists on the reliability of a task battery, thus precluding its use as an outcome measure in field research. This study investigated the intrasession reliability and systematic variation of force plate derived centre of pressure (COP) measures obtained during repeated performance of a task battery (lifting task, limits of stability and bipedal and unipedal stance). COP signals obtained during each task performance were processed to derive various time-domain COP measures. Statistical analyses revealed that 13 of the 19 COP measures displayed excellent relative (ICC(2,3) ≥ 0.75) and acceptable absolute reliability (SEM%: ≤ 10). Although COP measures displayed systematic variation, the differences were less or equal to the measurement error, except COP measures of unipedal stance and limits of stability. The chosen task battery is reliable and can be used for comprehensive evaluation of control of posture, in both field and laboratory research. Practitioner Summary: Repeated evaluation of multiple tasks together sequentially could introduce measurement variability. This study investigated intrasession reliability of a task battery representing common work-related postures. The chosen task battery was found to be reliable with acceptable measurement error and can be used in field research settings for evaluation of control of posture.

Can balance trampoline training promote motor coordination and balance performance in children with developmental coordination disorder?

The present study aimed to examine movement difficulties among typically developing 8- to 9-year-old elementary students in Greece and to investigate the possible effects of a balance training program to those children assessed with Developmental Coordination Disorder (DCD). The Body Coordination Test for Children (BCTC; Körperkoordinationstest fur Kinder, KTK, Kiphard & Schilling, 1974) was chosen for the purposes of this study and 20 children out of the total number of 200, exhibited motor difficulties indicating a probable DCD disorder. The 20 students diagnosed with DCD were equally separated into two groups where each individual of the experimental group was paired with an individual of the control group. The intervention group attended a 12-week balance training program while students of the second - control group followed the regular school schedule. All participants were tested prior to the start and after the end of the 12-week period by performing static balance control tasks while standing on an EPS pressure platform and structured observation of trampoline exercises while videotaping. The results indicated that after a 12-week balance training circuit including a trampoline station program, the intervention group improved both factors that were examined. In conclusion, balance training with the use of attractive equipment such as trampoline can be an effective intervention for improving functional outcomes and can be recommended as an alternative mode of physical activity.

Evaluation of Relationship between Trunk Muscle Endurance and Static Balance in Male Students

Purpose

Fatigue of trunk muscle contributes to spinal instability over strenuous and prolonged physical tasks and therefore may lead to injury, however from a performance perspective, relation between endurance efficient core muscles and optimal balance control has not been well-known. The purpose of this study was to examine the relationship of trunk muscle endurance and static balance.

Methods

Fifty male students inhabitant of Tehran university dormitory (age 23.9±2.4, height 173.0±4.5 weight 70.7±6.3) took part in the study. Trunk muscle endurance was assessed using Sørensen test of trunk extensor endurance, trunk flexor endurance test, side bridge endurance test and static balance was measured using single-limb stance test. A multiple linear regression analysis was applied to test if the trunk muscle endurance measures significantly predicted the static balance.

Results

There were positive correlations between static balance level and trunk flexor, extensor and lateral endurance measures (Pearson correlation test, r=0.80 and P<0.001; r=0.71 and P<0.001; r=0.84 and P<0.001, respectively). According to multiple regression analysis for variables predicting static balance, the linear combination of trunk muscle endurance measures was significantly related to the static balance (F (3,46) = 66.60, P<0.001). Endurance of trunk flexor, extensor and lateral muscles were significantly associated with the static balance level. The regression model which included these factors had the sample multiple correlation coefficient of 0.902, indicating that approximately 81% of the variance of the static balance is explained by the model.

Conclusion

There is a significant relationship between trunk muscle endurance and static balance.

Effects of a trampoline exercise intervention on motor performance and balance ability of children with intellectual disabilities

Balance and motor impairments are most evident among inactive individuals with ID that might be particularly susceptible to a loss of basic functioning and further limit the person's autonomy in activities of daily living. The aim of the study was to assess the effect of a 12-week trampoline exercise intervention program on motor and balance ability of school aged children with intellectual disability (ID). Eighteen healthy schools aged children (mean age=10.3 ± 1.6 years) with moderate ID were assigned either to an experimental group (n=9) or a control group (n=9). The experiment group attended a 12 weeks trampoline training intervention program consisting of daily individualized 20-min sessions, while the control group followed the regular school schedule. Balance was assessed using three tasks of increased difficulty (double-leg stance with eyes opened or closed, and one-leg stance with eyes opened) performed while standing on an electronic pressure platform (EPS). Motor performance of all participants was tested using sit and reach test and long and vertical jump tests all derived from the Eurofit Test Battery of physical fitness. Trampoline intervention resulted in significant improvements of participants' performance in all motor and balance tests. In conclusion, trampoline training can be an effective intervention for improving functional outcomes and can be recommended as an alternative mode of physical activity programming for improving balance and motor performance. Furthermore, it also supports the idea that individuals with ID require enjoyable and interesting intervention programs such as the trampoline program used in this study so as to remain active and consequently to facilitate their overall development and promote a more active and healthier way of life.

Effect of a hippotherapy intervention program on static balance and strength in adolescents with intellectual disabilities

The aim of this study was to assess the effects of a hippotherapy program on static balance and strength in adolescents with intellectual disability (ID). Nineteen adolescents with moderate ID were assigned either an experimental group (n=10) or a control group (n=9). The experimental group attended a 10-week hippotherapy program. To assess static balance, three tasks of increasing difficulty (Double-Leg Stance with opened or closed eyes, and One-Leg Stance with opened eyes) were performed while standing on an EPS pressure platform (Loran Engineering S.r.I., Bologna, Italy). The strength measurements consisted of three maximal isometric half-squats from the seating position (knee joint at 90°). The hippotherapy intervention program resulted in significant improvements in strength parameters, and on the more complex balance task (i.e. standing on one leg). In conclusion, this study provides evidence that hippotherapy can be used as an effective intervention for improving balance and strength in individuals with ID, and could thus influence functional activities and quality of life.

EFFECTS OF LATERALITY, ANKLE INVERSION AND STABILIZERS ON THE PLANTAR PRESSURE DISTRIBUTION DURING UNIPEDAL STANDING

The purpose of this research was to evaluate the standing stability with plantar pressure distribution (PPD), and to assess the effects of limb laterality, ankle inversion and stabilizer on PPD during unipedal standing. Nineteen young healthy adults were requested to stand on different inclined surfaces (level 0° and inclined 10° and 20°) with each foot. Three ankle stabilizer conditions were designed as barefoot control, elastic ankle tape and semi-rigid brace. Statistically analyzed with multivariate analysis of variance, the anterior/posterior (A/P) and medial/lateral (M/L) force ratios and total contact area (TPCA) were the main parameters to evaluate the stability. Compared with non-dominant side, the dominant foot was safer during unipedal standing with significantly greater TPCA, and especially when standing with ankle inversion due to additional significantly greater A/P force ratio. Ankle inversion harmed the stability while standing with the non-dominant foot due to significantly decreased A/P force ratio and local contact areas. Ankle brace improved the standing stability with significantly increased TPCA.

Habitual physical activity as a determinant of the effect of moderate physical exercise on postural control in older men

The aim of the study was to compare the effect of exercise on postural control (PC) among the elderly with lower or higher level of habitual physical activity (HPA). The study involved 17 elderly men (mean age 72.9 ± 4.79 years). Mean velocity of the center of pressure (COP) displacements was measured using a force plate both before and after cycle ergometer exercise. A significantly higher increase in mean velocity of COP displacements and its component in the sagittal plane were observed in the group with lower level of HPA in comparison with the group with higher HPA level. Simultaneously, a relatively similar reaction to the exercise in the frontal plane was observed in both groups, possibly connected to the specific type of used exercise, which mainly activated the sagittal muscles.

Effect of moderate physical exercise on postural control among 65-74 years old men

The aim of this study was to assess the changes in the postural control (PC) during quiet stance among elderly men with fatigue induced by moderate exercise, and to assess the relationships between changes in PC and somatic indices (body mass index (BMI), waist to hip ratio (WHR)), load during exercise, and post-exercise blood lactate (BL) concentration. The study involved 17 elderly men (68.4±2.9 years of age, ranging between 65 and 74 years). Mean velocity of the center of pressure (COP) displacements was measured using a force plate both before and after fatigue induced by a cycle ergometer exercise. Following physical exercise, the mean velocity of the COP and its components, both in the sagittal and frontal plane, increased significantly. It was found that increasing BMI was associated with increasing exercise-induced changes in the mean velocity of the frontal plane. Additionally, BL level was positively correlated with changes in the mean velocity of the sagittal plane. Higher post-exercise values of the mean velocity of the COP may suggest a temporary increase in the risk of falls. Therefore, it seems advisable to caution the elderly men in regards to the increased risk of falling following exercise. Analysis showed that the changes in the PC as indicated by the increase in the COP displacements velocity may be related to the level of fatigue (as indicated by BL). Moreover, elderly men possessing a higher BMI may exhibit a tendency toward the greater increase in the postural sway after exercise-induced fatigue.

The effects of dietary fasting on physical balance among healthy young women

Background

The study examined the effects of dietary fasting on physical balance among young healthy women.

Methods

This study undertaken involving 22 young healthy women (age = 22 ± 1.5) using a within subject counterbalanced 2-week crossover study design. Participants were asked to refrain from consuming any food or beverage for 12 hours prior to the fasting trial and to maintain their regular diet for the non-fasting trial. Measures included: a background questionnaire, 24-hour dietary recall, and functional reach and timed single-limb stances.

Results

Fasting resulted in significant declines in functional reach (p < 0.01), and ability to balance in a single limb stance with eyes open, on both the dominant and non-dominant legs (p < 0.01 and p < 0.01, respectively), and with eyes closed on the dominant leg (p < 0.01).

Conclusions

The findings have implications for athletic performance in younger individuals as well as emphasizing the need for health education for young women to avoid skipping meals.

Test-retest reliability [corrected] of center of pressure measures of postural stability during quiet standing in a group with musculoskeletal disorders consisting of low back pain, anterior cruciate ligament injury and functional ankle instability

Reliability is a population-specific property, but to the authors' knowledge there has been no study to determine the test-retest reliability of the postural stability measures such as center of pressure (COP) measures in the population of patients with musculoskeletal disorders (MSDs), while their clinical applications have been presented in literature. So, 33 patients with low back pain (LBP), anterior cruciate ligament (ACL) injury and functional ankle instability (FAI) randomly completed postural measurements with three levels of difficulty (rigid surface-eyes open, rigid surface-eyes closed, and foam surface-eyes closed) in two sessions. COP data were used to calculate standard deviation of amplitude, standard deviation of velocity, phase plane portrait, mean total velocity and area (95% confidence ellipse). Relative reliability of these measures was assessed using intraclass correlation coefficient (ICC) and absolute reliability using standard error of measurement (SEM) and coefficient of variation (CV). Also, minimal metrically detectable change (MMDC) was calculated to quantify intervention effects. Among different COP parameters, mean total velocity in all conditions of postural difficulty showed high to very high reliability, with ICC range of 0.74-0.91, SEM range of 0.09-0.40cm/s, CV range of 5.31-8.29% and MMDC range of 0.19-0.79cm/s. Phase plane portrait in anteroposterior-mediolateral (AP-ML) and ML direction were other best parameters with respect to the level of reliability. Mean total velocity and phase plane portrait parameters are suggested as good candidates to use for quantification and assessment of balance performance and identifying those with MSDs.

Motor coordination difficulties and physical fitness of extremely-low-birthweight children

Motor coordination difficulties and poor fitness exist in the extremely low birthweight (ELBW) population. This study investigated the relative impact of motor coordination on the fitness of ELBW children aged 11 to 13 years. One hundred and nine children were recruited to the study: 54 ELBW participants (mean age at assessment 12y 6mo; 31 male, 23 female; mean birthweight 769g, SD 148g; mean gestational age 26.6 weeks, SD 2.1 weeks) and 55 comparison children (mean age at assessment 12y 5mo; 28 males, 27 females; at least 37 weeks' gestation). All children completed the Movement Assessment Battery for Children (MABC), functional tests of postural stability and strength, growth measures, and tests of respiratory function. Maximal oxygen uptake (VO(2)max) was calculated from a 20m shuttle run test as a measure of fitness. The ELBW group had greater problems with postural stability (p=0.001) and motor coordination (p=0.001), with 70% rated as having a definite motor problem on the MABC brackets (those who scored less than the 5(th) centile on the MABC). The ELBW was also less fit than the comparison group (p=0.001), with 45% below the 10th centile for VO(2)max. There were differences between the groups for growth, strength, and particularly respiratory function. However, respiratory function did not significantly correlate with VO(2)max in the ELBW group. Motor coordination was the most powerful predictor of VO(2)max in both the ELBW (p=0.001) and the comparison groups (p=0.001).

Time-to-boundary measures of postural control during single leg quiet standing

A novel approach to quantifying postural stability in single leg stance is assessment of time-to-boundary (TTB) of center of pressure (COP) excursions. TTB measures estimate the time required for the COP to reach the boundary of the base of support if it were to continue on its instantaneous trajectory and velocity, thus quantifying the spatiotemporal characteristics of postural control. Our purposes were to examine: (a) the intrasession reliability of TTB and traditional COP-based measures of postural control, and (b) the correlations between these measures. Twenty-four young women completed three 10-second trials of single-limb quiet standing on each limb. Traditional measures included mean velocity, standard deviation, and range of mediolateral (ML) and anterior-posterior (AP) COP excursions. TTB variables were the absolute minimum, mean of minimum samples, and standard deviation of minimum samples in the ML and AP directions. The intrasession reliability of TTB measures was comparable to traditional COP based measures. Correlations between TTB and traditional COP based measures were weaker than those within each category of measures, indicating that TTB measures capture different aspects of postural control than traditional measures. TTB measures provide a unique method of assessing spatiotemporal characteristics of postural control during single limb stance.

Balance in single-limb stance after surgically treated ankle fractures: a 14-month follow-up

Background

The maintenance of postural control is fundamental for different types of physical activity. This can be measured by having subjects stand on one leg on a force plate. Many studies assessing standing balance have previously been carried out in patients with ankle ligament injuries but not in patients with ankle fractures. The aim of this study was to evaluate whether patients operated on because of an ankle fracture had impaired postural control compared to an uninjured age- and gender-matched control group.

Methods

Fifty-four individuals (patients) operated on because of an ankle fracture were examined 14 months postoperatively. Muscle strength, ankle mobility, and single-limb stance on a force-platform were measured. Average speed of centre of pressure movements and number of movements exceeding 10 mm from the mean value of centre of pressure were registered in the frontal and sagittal planes on a force-platform. Fifty-four age- and gender-matched uninjured individuals (controls) were examined in the single-limb stance test only. The paired Student t-test was used for comparisons between patients' injured and uninjured legs and between side-matched legs within the controls. The independent Student t-test was used for comparisons between patients and controls. The Chi-square test, and when applicable, Fisher's exact test were used for comparisons between groups. Multiple logistic regression was performed to identify factors associated with belonging to the group unable to complete the single-limb stance test on the force-platform.

Results

Fourteen of the 54 patients (26%) did not manage to complete the single-limb stance test on the force-platform, whereas all controls managed this (p < 0.001). Age over 45 years was the only factor significantly associated with not managing the test. When not adjusted for age, decreased strength in the ankle plantar flexors and dorsiflexors was significantly associated with not managing the test. In the 40 patients who managed to complete the single-limb stance test no differences were found between the results of patients' injured leg and the side-matched leg of the controls regarding average speed and the number of centre of pressure movements.

Conclusion

One in four patients operated on because of an ankle fracture had impaired postural control compared to an age- and gender-matched control group. Age over 45 years and decreased strength in the ankle plantar flexors and dorsiflexors were found to be associated with decreased balance performance. Further, longitudinal studies are required to evaluate whether muscle and balance training in the rehabilitation phase may improve postural control.

Balance in single-limb stance in patients with anterior cruciate ligament injury: relation to knee laxity, proprioception, muscle strength, and subjective function

BACKGROUND

It has been shown previously that an anterior cruciate ligament injury may affect postural control, measured by balance in single-limb stance. To our knowledge, no studies have reported the influence of measures of impairment on postural control after such an injury.

PURPOSE

To assess the influence of knee laxity, proprioception, and muscle strength on balance in single-limb stance and to study the correlation between balance in single-limb stance and subjective estimation of extremity function.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 36 patients with a unilateral, nonoperated, nonacute anterior cruciate ligament injury were examined with regard to anterior knee laxity, proprioception, muscle strength, and stabilometry (amplitude and average speed of the center of pressure movements). Subjective estimation of extremity function was measured on a visual analog scale.

RESULTS

The multiple regression analysis showed that high knee laxity values were associated with high amplitude values and low average speed. Poor proprioception and high muscle strength values were associated with low average speed among the women only. Low amplitude values correlated with better subjective function.

CONCLUSION

Anterior knee laxity, proprioception, and muscle strength seem to play a role in maintaining balance in single-limb stance. Patients with low amplitude values in stabilometry were those with better subjective function.

Influence of professional dance training on peak torque and proprioception at the ankle

OBJECTIVE

To investigate the influence of professional dance training on the peak torque ratio of plantar flexion to dorsiflexion (PF/DF), angle replication ability, and balance in comparison to age-matched and gender-matched controls. The effects of injuries sustained before and during the study time period were also assessed.

DESIGN

Prospective age-matched and gender-matched nonrandomized intervention study.

SETTING

Premises of the Orthopedic University Hospital, Heidelberg, where measuring apparatus belonging to the hospital was used for the tests.

PARTICIPANTS

One group of 42 dancers (31 female, 11 male) in professional training (State Academy) and 40 age-matched and gender-matched controls with no prior dance or specific sport training.

MAIN OUTCOME MEASUREMENTS

Isokinetic tests for peak torque at 30 degrees /s and 120 degrees /s, a passive angle-replication test (Biodex system 3), and a test of 1-legged standing were each carried out on 2 measurement dates (M1, M2): at the beginning of a season of professional dance training (M1) and after 5 months of such training (M2). Symptoms and/or injuries sustained during this period were ascertained continuously by means of questionnaires and interviews.

RESULTS

A significant increase in peak torque in PF was observed in both dancer groups and male controls between M1 and M2. A significant increase in PF/DF peak torque ratio at 30 degrees /s was observed in both male groups between M1 and M2. At M2, no significant differences in PF/DF peak torque ratio could be found between male dancers and controls, but at 30 degrees /s between the female groups. However, in both female groups, the PF/DF ratio was not found to increase significantly between M1 and M2. In the angle-replication and 1-legged standing test, no consistent improvement was observed between M1 and M2 in either dancers or controls. In the angle-replication test, there were no significant differences between dancers and controls at M2. In the 1-legged standing test, the dancers did significantly better than controls. A total of 7 ankle injuries were recorded, but no difference was found between injured and uninjured subjects in the proprioceptive tests either at M1, as the predicator, or at M2 as the residual.

CONCLUSIONS

Dance training did not increase the peak torque ratio of PF/DF within 5 months, but a group difference was found between the women groups. Ballet training alone without concurrent additional coordinative training does not lead to improvements in ankle joint position sense or improved measures of balance within this period of observation.

The effect of short-duration sub-maximal cycling on balance in single-limb stance in patients with anterior cruciate ligament injury: a cross-sectional study

Background

It has previously been shown that an anterior cruciate ligament (ACL) injury may lead to impaired postural control, and that the ability to maintain postural control is decreased by fatigue in healthy subjects. To our knowledge, no studies have reported the effect of fatigue on postural control in subjects with ACL injury. This study was aimed at examining the effect of fatigue on balance in single-limb stance in subjects with ACL injury, and to compare the effects, and the ability to maintain balance, with that of a control group of uninjured subjects.

Methods

Thirty-six patients with unilateral, non-operated, non-acute ACL injury, and 24 uninjured subjects were examined with stabilometry before (pre-exercise) and immediately after (post-exercise) short-duration, sub-maximal cycling. In addition, the post-exercise measurements were compared, to evaluate the instantaneous ability to maintain balance and any possible recovery. The amplitude and average speed of center of pressure movements were registered in the frontal and sagittal planes. The paired t-test was used for the intra-group comparisons, and the independent t-test for the inter-group comparisons, with Bonferroni correction for multiple comparisons.

Results

No differences were found in the effects of exercise between the patients and the controls. Analysis of the post-exercise measurements revealed greater effects or a tendency towards greater effects on the injured leg than in the control group. The average speed was lower among the patients than in the control group.

Conclusions

The results of the present study showed no differences in the effects of exercise between the patients and the controls. However, the patients seemed to react differently regarding ability to maintain balance in single-limb stance directly after exercise than the control group. The lower average speed among the patients may be an expression of different neuromuscular adaptive strategies than in uninjured subjects.