Postural Control Deficits During Static Single-leg Stance in Chronic Ankle Instability: A Systematic Review and Meta-Analysis

CONTEXT

Postural control deficits arising from injured ankles are central to chronic ankle instability (CAI) and its persistent symptoms. This is usually measured by recording the center of pressure (CoP) trajectory during static single-leg stance using a stable force plate. However, existing studies have produced conflicting results on whether this mode of measurement adequately reveals the postural deficits in CAI.

OBJECTIVE

To determine whether postural control during static single-leg stance is impaired in CAI patients when compared with uninjured healthy controls.

DATA SOURCES

Literature databases, PubMed, Embase, Web of Science, Cochrane Library, Scopus, CINAHL, and SPORTDiscus, were searched from inception to April 1, 2022, using ankle-, injury-, and posture-related terms.

STUDY SELECTION

Two authors independently performed the step-by-step screening of article titles, abstracts, and full texts to select peer-reviewed studies investigating CoP trajectory during static single-leg stance using a stable force plate in CAI patients and healthy controls. A total of 13,637 studies were reviewed, and 38 studies (0.003%) met the selection criteria.

STUDY DESIGN

Meta-analyses of descriptive epidemiological study.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

CoP parameters, sway directions, visual condition, and numerical data (means and standard deviations) were extracted.

RESULTS

The injured ankles of CAI patients had higher standard deviations of sway amplitude in both anterior-posterior and medial-lateral directions (standardized mean difference [SMD] = 0.36 and 0.31, respectively) under conditions of open eyes than controls. Higher mean sway velocity in anterior-posterior, medial-lateral, and total directions (SMD = 0.41, 0.37, and 0.45, respectively) with closed eyes was also found.

CONCLUSION

CAI patients had deficits of postural control during static single-leg stance, and these deficits were identified by the CoP trajectory. Further methodological explorations of CoP parameters and corresponding test conditions are required to enhance the sensitivity and reliability of postural deficit assessments in CAI using force plates.

Inertial sensors-based assessment to detect hallmarks of chronic ankle instability during single-leg standing: Is the healthy limb "healthy"?

BACKGROUND

Chronic ankle instability can be common in sportsmen and can increase the risk of damaging the articular surfaces and result in negative consequences to joint health. Balance assessment is often used to evaluate ankle instability characteristics and guide rehabilitation protocols. This study aims to investigate balance-related parameters in people with chronic ankle instability and healthy-matched controls, using inertial sensors.

METHODS

Ten young adults with a history of multiple ankle sprains (30 y, 25-34, 5 females) and ten matched healthy controls (30 y, 23-39, 5 females) were invited to participate in the study. Inertial sensors were placed on the head of the astragalus and on the chest to collect kinematic parameters during a 20-s single-leg stance performed on the leg with ankle instability (and corresponding for the healthy controls) and on the contralateral leg, randomly. Outcomes were calculated with MATLAB and subsequently analyzed.

FINDINGS

A significant group effect was found only for the inversion angle (F_1,15 = 12.514, p = 0.003, pη² = 0.455), consisting of individuals with ankle instability being characterized by higher inversion angles (4.999 degrees, 95% CI: 1.987-8.011, p = 0.003) without significant side differences. No significant side x group effects were found for the assessed parameters.

INTERPRETATION

Results from this study suggest that young adults with chronic ankle instability might be characterized by worse single-stance control in terms of inversion angle, and such worse performance could also be found in the contralateral leg. As such, inertial sensors could be used to assess kinematic parameters during balance tasks in people with chronic ankle instability.

Effect of sleep deprivation on postural control and dynamic stability in healthy young adults

BACKGROUND

Postural control results from non-linear interactions of multiple neuromusculoskeletal elements and contextual factors. The use of non-linear analyses that consider the temporal evolution of postural adjustments, such as sample entropy, could inform about the changes in postural control due to contextual disturbances such as sleep deprivation.

RESEARCH QUESTION

What are the effects of sleep deprivation on static postural control and dynamic stability in healthy young adults?

METHODS

A quasi-experimental study was performed with 17 healthy young males submitted to 24 h of monitored sleep deprivation. The postural control was measured using sample entropy, area, and total average velocity of the center of pressure on a force platform. The dynamic stability was measured using the Modified Star Excursion Balance Test (SEBTm) composite score for each lower limb. Repeated-measures analysis of variance (baseline × 12 h × 15 h × 18 h × 21 h × 24 h of sleep deprivation) verified the effect of sleep deprivation in the postural control variables. Paired t-test compared the composite score of the SEBTm between baseline and 24 h sleep deprivation.

RESULTS

Sample entropy decreased after 18 h of sleep deprivation (p = 0.032) and 24 h of sleep deprivation (p = 0.001). Despite the significant main effect for the area (p = 0.012) and speed (p = 0.007) of the center of pressure, no pairwise differences were identified in the post hoc analysis. The non-dominant lower limb SEBTm composite score was reduced after 24 h of sleep deprivation (p = 0.033), and no difference was observed in the dominant limb.

SIGNIFICANCE

Sleep deprivation reduced the adaptability in static postural control and dynamic stability of the non-dominant lower limb of healthy young male adults. Sample entropy seemed more sensitive to capture the effects of sleep deprivation than the classical postural control variables.

Study on the Influence of Proprioceptive Control versus Visual Control on Reaction Speed, Hand Coordination, and Lower Limb Balance in Young Students 14-15 Years Old

Currently, sports activities require a high reaction speed, coordination, and balance, highlighting the relationship between proprioceptive control, visual control, and hand–eye coordination in youth. The present research assessed the proprioceptive control, reaction speed, and lower limb balance of youth from five different schools to identify the level of physical preparation of children in this direction. This prospective study was conducted between 1 January 2020 and 29 February 2020. A total of 107 healthy children (33 females and 74 males) with appropriate medical conditions, aged between 14 and 15 years, from five Romanian schools were included in the experiment. All children were assessed for visual control and reaction speed with the ruler drop test, and for lower limb balance, the standing stork test was used. Statistical analysis included descriptive statistics, data series distribution, and comparison of means and medians using specific statistical programs. Comparison of medians highlighted significant statistical differences in the standing stork test with eyes closed and the dominant leg compared with the nondominant leg (p = 0.0057). Males were compared to females at the nondominant leg (p = 0.0179); closed eyes were compared with opened eyes for the nondominant leg (p = 0.0175 and 0.0006) for the ruler drop test comparing the dominant hand with the nondominant hand (p = 0.0212). Children who engage in sports activities better integrated sensory information in motor action execution based on reaction speed and coordination with the nondominant hand.

The Effect of Hip Joint Mobilizations Using a Mobilization Belt on Hip Range of Motion and Functional Outcomes

CONTEXT

Joint mobilizations have been studied extensively in the literature for the glenohumeral joint and talocrural joint (ankle). Consequently, joint mobilizations have been established as an effective means of improving range of motion (ROM) within these joints. However, there is a lack of extant research to suggest these effects may apply within another critical joint in the body, the hip.

OBJECTIVE

To examine the immediate effects of hip joint mobilizations on hip ROM and functional outcomes. Secondarily, this study sought to examine the efficacy of a novel hip mobilization protocol.

DESIGN

A prospective exploratory study.

SETTING

Two research labs.

PATIENTS OR OTHER PARTICIPANTS

The study included 19 active male (n = 8) and female (n = 11) college students (20.56 [1.5] y, 171.70 [8.6] cm, 72.23 [12.9] kg).

INTERVENTIONS

Bilateral hip mobilizations were administered with the use of a mobilization belt. Each participant received hip joint mobilization treatments once during 3 weekly sessions followed immediately by preintervention and postintervention testing/measurements. Testing for each participant occurred once per week, at the same time of day, for 3 consecutive weeks. Hip ROM was the first week, followed by modified Star Excursion Balance Test the second week and agility T test during the third week.

MAIN OUTCOMES MEASURES

Pretest and posttest measurements included hip ROM for hip flexion, extension, abduction, adduction, internal and external rotation, as well as scores on the modified Star Excursion Balance Test (anterior, posterolateral, and posteromedial directions) and agility T test.

RESULTS

A significant effect for time was found for hip adduction, internal and external rotation ROM, as well as the posterolateral and posteromedial directions of the modified Star Excursion Balance Test. A separate main effect for both limbs was found for adduction and internal rotation ROM.

CONCLUSION

Isolated immediate changes in ROM and functional outcomes were evident. Further evaluation is needed.

Effect of Chronic Ankle Sprain on Pain, Range of Motion, Proprioception, and Balance among Athletes

Background: Ankle sprains are common among physically active individuals, especially among athletes. Majority of those who suffer ankle sprains have residual symptoms including pain, episodes of giving way, compromised proprioception and neuromuscular control, and re-injury leading to chronic ankle instability. The aim of this study was to see the effect of chronic ankle sprain on pain, range of motion, proprioception, and, static and dynamic balance among athletes. Methods: A total of 80 athletes, aged 18 to 25 years, involved in track-and-field sports were invited to participate in this study. They were divided in two groups. Athletes with history of grade 1 or 2 ankle sprain on either side requiring medical care who reported at least three episodes of ankle giving way in past 12 months were included in group A. An equal number of healthy athletes without any history of ankle sprain or injury in the lower limbs in the past one year matched by sex, age, height, weight, and limb dominance, were included in group B (control). Outcome measures: Participant's pain, range of motion, proprioception and balance (static and dynamic) was measured using visual analog scale, half circle goniometer, degree of foot position sense, single leg stance time and Y-balance test respectively. Results: Although there were no differences in the active ankle joint range of motion (p > 0.05) in comparison to the control group, athletes with chronic ankle sprain reported mild pain and statistically significant (p < 0.05) deficits in foot proprioception, static and dynamic balance. Conclusions: Deficits in foot proprioception, static and dynamic balance even one year after the ankle sprain could be the reason for limitations in the dynamic defense system of the joint that predisposes to recurrent injury and instability. It is essential to understand the normal clinical course and risk factors for athletes who sustain sprain before devising a long term comprehensive rehabilitation program that focuses on mechanical and functional insufficiencies in order to improve their functional performance and prevent the risk of recurrent sprain.

Systematic review of motor control and somatosensation assessment tests for the ankle

Background/Aim

Ankle sprains are frequent musculoskeletal injuries that can lead to sensorimotor deficits provoking long-term instability at the ankle joint. A broad variety of clinical tests currently exist to assess sensorimotor processing, and are commonly clinically referred to as proprioceptive tests. However, there is a discrepancy in the use of the term proprioception when looking at the main outcome of these tests. As identifying specific deficits is important for motor recovery, it is critical for clinicians to select the most appropriate tests.

Methods

A systematic review of four databases was performed to provide an up-to-date review of the psychometric properties of available tests referred to as proprioceptive tests. Seventy-nine articles on eight ankle proprioceptive tests were included and critically appraised. Data on validity, reliability and responsiveness were extracted from the included articles and synthesised. The tests reviewed were then divided into two categories based on their main outcome: motor control or somatosensation.

Results

Strong evidence showed that the Star Excursion Balance Test, a motor control test, is capable of differentiating between stable and unstable ankles. Moderate evidence suggests that somatosensation tests, such as Joint Position Sense, are also valid and reliable, but their responsiveness has yet to be evaluated.

Conclusions

Together, these findings indicate that the Star Excursion Balance Test can be used in the clinic to assess motor control based on its excellent psychometric properties. However, as ankle stability control involves complex sensorimotor interactions, care has to be taken regarding the use of this test as a specific tool for proprioception assessment.

Comparison of Static and Dynamic Balance in Male Football and Basketball Players

Introduction. The aim of the present study was to compare static and dynamic balance among professional athletes in football and basketball. Methods. In this cross-sectional study, 47 professional, male football and basketball players from Pro League in Iran participated. They were divided into 3 groups. Group 1 included 16 participants with history of grade 1 or 2 single ankle sprain within the past 6 months. Group 2 included 17 participants with recurrent ankle sprain. Group 3 included 14 participants without history of ankle sprain. Static and dynamic balance were measured by the Balance Error Scoring System (BESS) and modified Star Excursion Balance Test (SEBT), respectively. Results. For the single-leg stance on a firm surface, group 2 scored errors with a high mean value of 3.94 compared with the other 2 groups, and the difference was statistically significant (P = .03). Significant differences in BESS scores are observed on both surfaces across the tandem limb between groups 2 and 3. Conclusion. The measures from the SEBTs may not reflect the balance performance especially in well-trained athletes who have a better balance when performing sport-related skills. However, BESS includes static postures, and it may reflect postural deficits better than dynamic tests in the more experienced athlete. Level of Evidence: Diagnostic, Level IV.

Weight, BMI and stability are risk factors associated with lateral ankle sprains and chronic ankle instability: a meta-analysis

IMPORTANCE

Lateral ankle sprains (LAS) are common in the general population and may lead to chronic ankle instability (CAI). If patients at risk could be identified, they could receive adequate and on-time treatment.

OBJECTIVE

The purpose of the current review was to identify all reported intrinsic factors associated with sustaining a LAS or progressing to CAI after an initial sprain.

EVIDENCE REVIEW

PubMed, Embase, MEDline, Cochrane and PEDro were searched for studies published until July 2019. Articles were selected if they included intrinsic factors related to LAS or CAI, subjects of at least 16 years old, and contained a minimum of 10 patients and 10 controls. Studies were excluded if they concerned reviews or case reports, included patients with previous surgical interventions, concomitant injuries or joint pathology other than ankle instability. Quality of included studies was assessed using the Quality in Prognostic Studies tool and quality of evidence was assessed using the GRADEpro tool. In case outcomes were described by at least three studies, data were pooled and assessed by performing a meta-analysis. Based on the pooled data, either a fixed-effects model or random-effects model was selected to correct for the degree of heterogeneity.

FINDINGS

The search resulted in a total of 4154 studies. After title and abstract screening and subsequent full-text screening, 80 relevant studies were included. Results of the meta-analyses indicated that, compared with healthy controls, patients with LAS had a higher mean body mass index (BMI). In patients with CAI, a higher weight and a longer time to stabilise after performing a task (eg, jumping) were found compared with healthy controls. Other outcomes could not be compared using a meta-analysis due to heterogeneity in outcome measurement and the great number of different outcomes reported. Identification of the risk factors when patients present themselves after a LAS may help to determine which patients are at risk of recurrent sprains or developing CAI.

CONCLUSIONS AND RELEVANCE

Based on the findings in this review, a higher BMI, and a higher weight and neuromuscular stability deficits may be regarded risk factors for sustaining a LAS or developing CAI, respectively.

LEVEL OF EVIDENCE

III.

Ability of Functional Performance Tests to Identify Individuals With Chronic Ankle Instability: A Systematic Review With Meta-Analysis

OBJECTIVE

The purpose of this systematic review with meta-analysis was to determine the effectiveness of functional performance tests (FPTs) in differentiating between individuals with chronic ankle instability (CAI) and healthy controls.

DATA SOURCES

The National Library of Medicine Catalog (PubMed), the Cumulative Index for Nursing and Allied Health Literature (CINAHL), and the SPORTDiscus, from inception to June 2017 were searched. Search terms consisted of: "Functional Performance Test*" OR "Dynamic Balance Test*" OR "Postural Stability Test*" OR "Star Excursion Balance Test*" OR "Hop Test*" AND "Ankle Instability" OR "Ankle Sprain." Included articles assessed differences in FPTs in patients with CAI compared with a control group.

MAIN RESULTS

Included studies were assessed for methodological quality and level of evidence. Individual and mean effect sizes were also calculated for FPTs from the included articles. Twenty-nine studies met the criteria and were analyzed. The most common FPTs were timed-hop tests, side-hop, multiple-hop test, single-hop for distance, foot-lift test, and the Star Excursion Balance Tests (SEBTs). The side-hop (g = -1.056, P = 0.009, n = 7), timed-hop tests (g = -0.958, P = 0.002, n = 9), multiple-hop test (g = 1.399, P < 0.001, n = 3), and foot-lift tests (g = -0.761, P = 0.020, n = 3) demonstrated the best utility with large mean effect sizes, whereas the SEBT anteromedial (g = 0.326, P = 0.022, n = 7), medial (g = 0.369, P = 0.006, n = 7), and posteromedial (g = 0.374, P < 0.001, n = 13) directions had moderate effects.

CONCLUSIONS

The side-hop, timed-hopping, multiple-hop, and foot-lift seem the best FPTs to evaluate individuals with CAI. There was a large degree of heterogeneity and inconsistent reporting, potentially limiting the clinical implementation of these FPTs. These tests are cheap, effective, alternatives compared with instrumented measures.

Factors Contributing to Chronic Ankle Instability: A Systematic Review and Meta-Analysis of Systematic Reviews

BACKGROUND

Many factors are thought to contribute to chronic ankle instability (CAI). Multiple systematic reviews have synthesised the available evidence to identify the primary contributing factors. However, readers are now faced with several systematic reviews that present conflicting findings.

OBJECTIVE

The aim of this systematic review and meta-analysis was to establish the statistical significance and effect size of primary factors contributing to CAI and to identify likely reasons for inconsistencies in the literature.

METHODS

Relevant health databases were searched: CINAHL, MEDLINE, PubMed, Scopus and SPORTDiscus. Systematic reviews were included if they answered a focused research question, clearly defined the search strategy criteria and study selection/inclusion and completed a comprehensive search of the literature. Included reviews needed to be published in a peer-reviewed journal and needed to review observational studies of factors and/or characteristics of persons with CAI, with or without meta-analysis. There was no language restriction. Studies using a non-systematic review methodology (e.g. primary studies and narrative reviews) were excluded. Methodological quality of systematic reviews was assessed using the modified R-AMSTAR tool. Meta-analysis on included primary studies was performed.

RESULTS

Only 17% of primary studies measured a clearly defined CAI population. There is strong evidence to support the contribution of dynamic balance, peroneal reaction time and eversion strength deficits and moderate evidence for proprioception and static balance deficits to non-specific ankle instability.

CONCLUSIONS

Evidence from previous systematic reviews does not accurately reflect the CAI population. For treatment of non-specific ankle instability, clinicians should focus on dynamic balance, reaction time and strength deficits; however, these findings may not be translated to the CAI population. Research should be updated with an adequately controlled CAI population.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2016, CRD42016032592.

Using Balance Tests to Discriminate Between Participants With a Recent Index Lateral Ankle Sprain and Healthy Control Participants: A Cross-Sectional Study

CONTEXT

The first step to identifying factors that increase the risk of recurrent ankle sprains is to identify impairments after a first sprain and compare performance with individuals who have never sustained a sprain. Few researchers have restricted recruitment to a homogeneous group of patients with first sprains, thereby introducing the potential for confounding.

OBJECTIVE

To identify impairments that differ in participants with a recent index lateral ankle sprain versus participants with no history of ankle sprain.

DESIGN

Cross-sectional study.

PATIENTS OR OTHER PARTICIPANTS

We recruited a sample of convenience from May 2010 to April 2013 that included 70 volunteers (age = 27.4 ± 8.3 years, height = 168.7 ± 9.5 cm, mass = 65.0 ± 12.5 kg) serving as controls and 30 volunteers (age = 31.1 ± 13.3 years, height = 168.3 ± 9.1 cm, mass = 67.3 ± 13.7 kg) with index ankle sprains.

MAIN OUTCOME MEASURE(S)

We collected demographic and physical performance variables, including ankle-joint range of motion, balance (time to balance after perturbation, Star Excursion Balance Test, foot lifts during single-legged stance, demi-pointe balance test), proprioception, motor planning, inversion-eversion peak power, and timed stair tests. Discriminant analysis was conducted to determine the relationship between explanatory variables and sprain status. Sequential discriminant analysis was performed to identify the most relevant variables that explained the greatest variance.

RESULTS

The average time since the sprain was 3.5 ± 1.5 months. The model, including all variables, correctly predicted a sprain status of 77% (n = 23) of the sprain group and 80% (n = 56) of the control group and explained 40% of the variance between groups ([Formula: see text] = 42.16, P = .03). Backward stepwise discriminant analysis revealed associations between sprain status and only 2 tests: Star Excursion Balance Test in the anterior direction and foot lifts during single-legged stance ([Formula: see text] = 15.2, P = .001). These 2 tests explained 15% of the between-groups variance and correctly predicted group membership of 63% (n = 19) of the sprain group and 69% (n = 48) of the control group.

CONCLUSIONS

Balance impairments were associated with a recent first ankle sprain, but proprioception, motor control, power, and function were not.

Interrater reliability of the star excursion balance test

CONTEXT

Dynamic postural control has gained popularity as a more useful assessment of function than static postural control. One measurement of dynamic postural control that has increased in frequency of use is the Star Excursion Balance Test (SEBT). Although the intrarater reliability of the SEBT is excellent, few authors have determined interrater reliability. Preliminary evidence has shown poor reliability between assessors.

OBJECTIVE

To determine interrater reliability using a group of investigators at 2 testing sites. A corollary purpose was to examine the interrater reliability when using normalized and nonnormalized performance scores on the SEBT.

DESIGN

Descriptive laboratory study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 29 healthy participants between 18 and 50 years of age.

INTERVENTION(S)

Participants were evaluated by 5 raters at 2 testing sites. After participants performed 4 practice trials, each rater assessed 3 test trials in the anterior, posteromedial, and posterolateral reaching directions of the SEBT.

MAIN OUTCOME MEASURE(S)

Normalized and nonnormalized (leg-length) reaching distances were analyzed. Additionally, the mean and maximum values from the 3 test trials were analyzed, producing a total of 16 variables.

RESULTS

For all 16 measures, the interrater reliability was excellent. For the normalized maximum excursion distances, the intraclass correlation coefficients (1,1) ranged from 0.86 to 0.92. Reliability for the nonnormalized measurements was stronger, ranging from 0.89 to 0.94.

CONCLUSIONS

When the raters have been trained by an experienced rater, the SEBT is a test with excellent reliability when used across multiple raters in different settings. This information adds to the body of knowledge that exists regarding the usefulness of the SEBT as an assessment tool in clinical and research practice. Establishing excellent interrater reliability with normalized and nonnormalized scores strengthens the evidence for using the SEBT, especially at multiple sites.

Using the Star Excursion Balance Test to assess dynamic postural-control deficits and outcomes in lower extremity injury: a literature and systematic review

CONTEXT

A dynamic postural-control task that has gained notoriety in the clinical and research settings is the Star Excursion Balance Test (SEBT). Researchers have suggested that, with appropriate instruction and practice by the individual and normalization of the reaching distances, the SEBT can be used to provide objective measures to differentiate deficits and improvements in dynamic postural-control related to lower extremity injury and induced fatigue, and it has the potential to predict lower extremity injury. However, no one has reviewed this body of literature to determine the usefulness of the SEBT in clinical applications.

OBJECTIVE

To provide a narrative review of the SEBT and its implementation and the known contributions to task performance and to systematically review the associated literature to address the SEBT's usefulness as a clinical tool for the quantification of dynamic postural-control deficits from lower extremity impairment.

DATA SOURCES

Databases used to locate peer-reviewed articles published from 1980 and 2010 included Derwent Innovations Index, BIOSIS Previews, Journal Citation Reports, and MEDLINE.

STUDY SELECTION

The criteria for article selection were (1) The study was original research. (2) The study was written in English. (3) The SEBT was used as a measurement tool.

DATA EXTRACTION

Specific data extracted from the articles included the ability of the SEBT to differentiate pathologic conditions of the lower extremity, the effects of external influences and interventions, and outcomes from exercise intervention and to predict lower extremity injury.

DATA SYNTHESIS

More than a decade of research findings has established a comprehensive portfolio of validity for the SEBT, and it should be considered a highly representative, noninstrumented dynamic balance test for physically active individuals. The SEBT has been shown to be a reliable measure and has validity as a dynamic test to predict risk of lower extremity injury, to identify dynamic balance deficits in patients with a variety of lower extremity conditions, and to be responsive to training programs in both healthy people and people with injuries to the lower extremity. Clinicians and researchers should be confident in employing the SEBT as a lower extremity functional test.

Inclusion criteria when investigating insufficiencies in chronic ankle instability

INTRODUCTION

The development of chronic ankle instability (CAI) is the primary residual deficit after ankle joint sprain. It has been proposed that CAI is characterized by two entities, namely, mechanical instability and functional instability. Each of these entities in turn is composed of various insufficiencies. Research of functional insufficiencies to date has shown large variances in results. One particular reason for this could be discrepancies in inclusion criteria and definitions between CAI, mechanical instability, and functional instability used in the literature. Thus, we endeavored to undertake a systematic investigation of those studies published in the area of CAI to identify if there is a large discrepancy in inclusion criteria across studies.

METHODS

A systematic search of the following databases was undertaken to identify relevant studies: Cochrane Central Register of Controlled Trials, PubMed, CINAHL, SportDiscus, PEDro, and AMED.

RESULTS

The results of this study indicate that there is a lack of consensus across studies regarding what actually constitutes ankle instability. Furthermore, it is evident that the majority of studies use very different inclusion criteria, which leads to a nonhomogenous population and to difficulties when comparing results across studies.

CONCLUSIONS

Future studies should endeavor to be specific with regard to the exact inclusion criteria being used. Particular emphasis should be given to issues such as the number of previous ankle sprains reported by each subject and how often and during which activities episodes of "giving way" occur as well as the presence of concomitant symptoms such as pain and weakness. We recommend that authors use one of the validated tools for discriminating the severity of CAI. Furthermore, we have provided a list of operational definitions and key criteria to be specified when reporting on studies with CAI subjects.

Balance performance in male and female collegiate basketball athletes: influence of testing surface

The Star Excursion Balance Test (SEBT) is a simple and cost-effective balance test. Information on SEBT performance in athletic populations and under varying testing surfaces is needed to fully elucidate the clinical and training utility of this task. The purpose of this study was to examine SEBT performance in division I, collegiate basketball athletes (men = 9, women = 7) and in a healthy nonathlete control group (men = 7, women = 9). Each participant performed the SEBT with their dominant and nondominant limbs on stable and unstable testing surfaces while reaching in the anterior, medial, and posterior directions. No significant differences resulted between the dominant and nondominant limbs (p > 0.05). Significant differences were found between the basketball and control groups in all directions (p < 0.01) and the average reach score (p < 0.01) with the control group reaching 6-7% farther than the basketball group. A significant main effect for gender (collapsed across group and limb) was present in the posterior direction (p = 0.02). The SEBT performance in the medial and posterior directions and the average score were significantly (p < 0.01) reduced during testing on the unstable surface. These results suggest that athletic status may be a factor to consider when interpreting SEBT reach performance. Future research should examine the influence of SEBT testing in other athletic populations. Further, use of an unstable surface provided a greater challenge to balance. Additional research may provide insight into the role of using an unstable surface with the SEBT as part of an injury risk assessment and its use in identifying limb differences between injured and uninjured limbs.

Bilateral balance impairments after lateral ankle trauma: a systematic review and meta-analysis

Research indicates that balance is impaired in the involved limb following an ankle injury. However, bilateral balance impairments are a viable reason for previous non-significant findings between involved and uninvolved limbs. The purpose of this investigation was to conduct a meta-analysis on studies reporting the effects of lateral ankle trauma on balance of the involved and uninvolved limb after acute ankle injury and chronic ankle instability. Twelve studies qualified for inclusion and assessed static balance for both the involved and uninvolved limbs post-injury and a control group. Meta-analyses calculated standardized mean difference effects and explored moderating variables for the involved and uninvolved limbs relative to controls. A significant cumulative effect size (ES=0.448, p<0.00001) indicated that balance of the involved limb is impaired after a history of ankle injury. Moderator variable analysis revealed that both acute (ES=0.529, p<0.0002) and chronic (ES=0.338, p<0.001) lateral ankle trauma negatively affected balance. Analysis of the uninvolved limb also revealed postural stability impairments (ES=0.275, p<0.003). Additional, moderator analysis showed a significant acute effect (ES=0.564, p<0.0001), but failed to find significance for individuals with chronic ankle instability (ES=0.070, p=0.552). These findings provide strong evidence that balance is bilaterally impaired after an acute lateral ankle sprain. However, these findings suggest that bilateral balance deficits are not present in patients with chronic ankle instability. Based on these findings, the uninvolved limb should not be used as a reference for "normal balance" following an acute lateral ankle sprain. Further, patients with acute lateral ankle sprains should undergo balance training on both limbs.

Sensorimotor function as a predictor of chronic ankle instability

BACKGROUND

Recurrent ankle injury occurs in 70% of individuals experiencing a lateral ankle sprain. The cause of this high level of recurrence is currently unknown. Researchers have begun to investigate sensorimotor deficits as one possible cause with inconclusive and often conflicting results. The purpose of this study was to further the understanding of the role of sensorimotor deficits in the chronically unstable ankle by establishing which specific measures best distinguish between chronically unstable and healthy ankles.

METHODS

Twenty-two participants with chronic ankle instability and 21 healthy matched controls volunteered. Twenty-five variables were measured within four sensorimotor constructs: joint kinesthesia (isokinetic dynamometer), static balance (force plate), dynamic balance (Star Excursion Balance Test) and motoneuron pool excitability (electromyography).

FINDINGS

The above variables were evaluated using a discriminant function analysis [Wilks'Lambda=0.536 chi(2)(7, N=43)=22.118, P=0.002; canonical correlation=0.681]. The variables found to be significant were then used to assess group discrimination. This study revealed that seven separate variables from the static balance (anterior/posterior and medial/lateral displacement and velocity) and motoneuron pool excitability constructs (single-legged recurrent inhibition and single- and double-legged paired reflex depression) accurately classified over 86% of participants with unstable ankles.

INTERPRETATION

These results suggest that a multivariate approach may be necessary to understand the role of sensorimotor function in chronic ankle instability, and to the development of appropriate rehabilitation and prevention programs. Out of the four overall constructs, only two were needed to accurately classify the participants into two groups. This indicates that static balance and motoneuron pool excitability may be more clinically important in treatment and rehabilitation of chronic ankle instability than functional balance or joint kinesthesia.

Evidence of sensorimotor deficits in functional ankle instability: a systematic review with meta-analysis

Functional ankle instability (FAI) has been associated with impaired sensorimotor function; however individual studies have produced conflicting results. In an attempt to reduce this ambiguity, a systematic review with meta-analysis was undertaken to determine which sensorimotor deficits exist with FAI. Fifty-three studies assessing sensorimotor factors in subjects with FAI were included from 465 identified articles. Studies were rated for methodological quality and data were pooled for peroneal reaction time, joint position sense, and postural sway during single-leg stance and time to stabilisation from a single-leg jump. Data on joint movement sense were unable to be pooled. When subjects with unstable ankles were compared to healthy controls, sensorimotor impairments were demonstrated for passive joint position sense (mean difference (MD)=0.7 degrees , 95% confidence interval (CI): 0.2-1.2 degrees , p=0.004), active joint position sense (MD=0.6 degrees , 95% CI: 0.2-1.0 degrees , p=0.002), postural sway in single-leg stance (standardised MD (SMD)=0.6, 95% CI: 0.2-1.0, p=0.002), the star excursion balance test (SMD=0.4, 95% CI: 0.1-0.7, p=0.009), and time to stabilisation from a single-leg jump in a medio-lateral (MD=0.6 ms, 95% CI: 0.4-0.8, p<0.0001) and an antero-posterior direction (MD=0.7 ms, 95% CI: 0.4-1.0, p<0.0001). Peroneal reaction time was not affected. Sensorimotor deficits occur for joint position sense and postural control in subjects with FAI. Deficits in peroneal muscle reaction time following perturbation are not evident.

Unilateral balance performance in female collegiate soccer athletes

The Star Excursion Balance Test (SEBT) is a unilateral balance task designed to evaluate dynamic postural control. This investigation explored the relationship between limb preference, strength, and performance on the SEBT in NCAA Division I, female collegiate soccer athletes (nonsoccer, n = 11; soccer, n = 12). Each participant completed maximal, concentric test efforts at a velocity of 90 degrees x s(-1) for supine ankle dorsiflexion (ADF) and plantarflexion (APF) and at 60 degrees x s(-1) for the seated leg extension (LE) and flexion (LF) and supine hip extension (HE) and flexion (HF). In addition, participants performed maximal SEBT reaches in the anterior, medial, and posterior directions. All testing was completed on both limbs. These results indicate that SEBT performance is similar for both limbs in both groups. The soccer group, however, reached significantly farther than the nonsoccer group, suggesting that the SEBT may be sensitive to training status and/or sport-related adaptations. The concentric strength results indicate that despite group differences in all strength tests, strength in general was not highly correlated to SEBT performance. Thus, neuromuscular factors above and beyond strength may have accounted for the group differences in SEBT performance. The SEBT may be a useful tool for determining the relative effectiveness of an intervention designed to improve postural control.

Prophylactic ankle braces and star excursion balance measures in healthy volunteers

CONTEXT

The effects of prophylactic ankle braces on lower extremity functional performance in healthy participants have not been studied extensively.

OBJECTIVE

To determine if prophylactic ankle braces affected multidirectional reach distances during a test of dynamic balance.

DESIGN

Crossover.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-six healthy, physically active volunteers (18 men, 18 women; age = 23.6 +/- 2.7 years, height = 173.8 +/- 9.3 cm, mass = 74.4 +/- 12.7 kg, reach-leg length = 91.9 +/- 5.1 cm).

INTERVENTION(S)

Volunteers performed balance testing in 3 conditions: unbraced, while wearing a semirigid ankle brace, and while wearing a lace-up ankle brace.

MAIN OUTCOME MEASURE(S)

We used the Star Excursion Balance Test, calculating the mean of 3 attempts in 8 directions (anterior, anterior-medial, medial, posterior-medial, posterior, posterior-lateral, lateral, and anterior-lateral), normalized by the participant's reach-leg length. Data were collected after 6 practice attempts for each of the conditions according to a balanced Latin square.

RESULTS

Bracing condition had no effect (P > .05) on any of the Star Excursion Balance Test directional measures. The largest mean difference due to bracing was 2.5% between the lace-up brace condition and the control in the posterior reach direction. This indicates that the actual reach differences due to bracing were less than 5.08 cm (2 inches) in length.

CONCLUSIONS

Clinicians can be confident that the prophylactic use of ankle braces does not disrupt lower extremity dynamic balance during a reaching task in healthy participants.

Simplifying the star excursion balance test: analyses of subjects with and without chronic ankle instability

STUDY DESIGN

Case control study.

OBJECTIVES

The objectives of this study are: (1) to perform factor analyses on data from the 8 components of the star excursion balance test (SEBT) in subjects with and without chronic ankle instability (CAI) in an effort to reduce the number of components of the SEBT, (2) to assess the relationships between performance of the different reach directions using correlation analyses, and (3) to determine which components of the SEBT are most affected by CAI.

BACKGROUND

The SEBT is a series of 8 lower-extremity-reaching tasks purported to be useful in identifying lower extremity functional deficits.

METHODS AND MEASURES

Forty-eight young adults with unilateral CAI (22 males, 26 females; mean +/- SD age, 20.9 +/- 3.2 years; mean +/- SD height, 173.6 +/- 11.1 cm; mean +/- SD mass, 80.1 +/- 22.1 kg) and 39 controls (23 males, 16 females; mean +/- SD age, 20.7 +/- 2.4 years; mean +/- SD height, 174.1 +/- 12.9 cm; mean +/- SD mass, 75.1 +/- 18.6 kg) performed 3 trials of the 8 tasks with each of their limbs. Separate exploratory factor analyses were performed on data for involved limbs of the CAI group, uninvolved limbs of the CAI and control groups, and both limbs of the CAI and control groups. Pearson product moment correlations were calculated to identify the relationships between the different reach directions. A series of eight 2 x 2 analyses of variance were calculated to determine the influence of group (CAI, control) and side (involved, uninvolved) on performance of the 8 tasks.

RESULTS

For all 3 factor analyses, only 1 factor in each analysis produced an eigenvalue greater than 1 and the posteromedial reach score was the most strongly correlated task with the computed factor (alpha > .90), although all 8 tasks produced alpha scores greater than .67. Bivariate correlations between specific reach directions ranged from .40 to .91. Subjects with CAI reached significantly less on the anteromedial, medial, and posteromedial directions when balancing on their involved limbs compared to their uninvolved limbs and the side-matched limbs of controls.

CONCLUSIONS

The posteromedial component of the SEBT is highly representative of the performance of all 8 components of the test in limbs with and without CAI. There is considerable redundancy in the 8 tasks. The anteromedial, medial, and posteromedial reach tasks may be used clinically to test for functional deficits related to CAI in lieu of testing all 8 tasks. There is a need for a hypothesis-driven study to confirm the results of this exploratory study.