Claire E. Hiller

Selection criteria for patients with chronic ankle instability in controlled research: a position statement of the international ankle consortium

The International Ankle Consortium is an international community of researchers and clinicians whose primary scholastic purpose is to promote scholarship and dissemination of research-informed knowledge related to pathologies of the ankle complex. The constituents of the International Ankle Consortium and other similar organizations have yet to properly define the clinical phenomenon known as chronic ankle instability (CAI) and its related characteristics for consistent patient recruitment and advancement of research in this area. Although research on CAI and awareness of its impact on society and healthcare systems have grown substantially in the last 2 decades, the inconsistency in participant/patient selection criteria across studies presents a potential obstacle to addressing the problem properly. This major gap within the literature limits the ability to generalize this evidence to the target patient population. Therefore, there is a need to provide standards for patient/participant selection criteria in research focused on CAI, with justifications using the best available evidence.

Chronic Ankle Instability: Evolution of the Model

CONTEXT The Hertel model of chronic ankle instability (CAI) is commonly used in research but may not be sufficiently comprehensive. Mechanical instability and functional instability are considered part of a continuum, and recurrent sprain occurs when both conditions are present. A modification of the Hertel model is proposed whereby these 3 components can exist independently or in combination. OBJECTIVE To examine the fit of data from people with CAI to 2 CAI models and to explore whether the different subgroups display impairments when compared with a control group. DESIGN Cross-sectional study. PATIENTS OR OTHER PARTICIPANTS Community-dwelling adults and adolescent dancers were recruited: 137 ankles with ankle sprain for objective 1 and 81 with CAI and 43 controls for objective 2. INTERVENTION(S) Two balance tasks and time to recover from an inversion perturbation were assessed to determine if the subgroups demonstrated impairments when compared with a control group (objective 2). MAIN OUTCOME MEASURE(S) For objective 1 (fit to the 2 models), outcomes were Cumberland Ankle Instability Tool score, anterior drawer test results, and number of sprains. For objective 2, outcomes were 2 balance tasks (number of foot lifts in 30 seconds, ability to balance on the ball of the foot) and time to recover from an inversion perturbation. The Cohen d was calculated to compare each subgroup with the control group. RESULTS A total of 56.5% of ankles (n = 61) fit the Hertel model, whereas all ankles (n = 108) fit the proposed model. In the proposed model, 42.6% of ankles were classified as perceived instability, 30.5% as recurrent sprain and perceived instability, and 26.9% as among the remaining groups. All CAI subgroups performed more poorly on the balance and inversion-perturbation tasks than the control group. Subgroups with perceived instability had greater impairment in single-leg stance, whereas participants with recurrent sprain performed more poorly than the other subgroups when balancing on the ball of the foot. Only individuals with hypomobility appeared unimpaired when recovering from an inversion perturbation. CONCLUSIONS The new model of CAI is supported by the available data. Perceived instability alone and in combination characterized the majority of participants. Several impairments distinguished the sprain groups from the control group.

Characteristics of people with recurrent ankle sprains: a systematic review with meta-analysis

Objective To examine whether people with recurrent ankle sprain, have specific physical and sensorimotor deficits. Design A systematic review of journal articles in English using electronic databases to September 2009. Included articles compared physical or sensorimotor measures in people with recurrent (≥2) ankle sprains and uninjured controls. Main outcome groups Outcome measures were grouped into: physical characteristics, strength, postural stability, proprioception, response to perturbation, biomechanics and functional tests. A meta-analysis was undertaken where comparable results within an outcome group were inconsistent. Results Fifty-five articles met the inclusion criteria. Compared with healthy controls, people with recurrent sprains demonstrated radiographic changes in the talus, changes in foot position during gait and prolonged time to stabilisation after a jump. There were no differences in ankle range of motion or functional test performance. Pooled results showed greater postural sway when standing with eyes closed (SMD=0.9, 95% CI 0.4 to 1.4) or on unstable surfaces (0.5, 0.1 to 1.0) and decreased concentric inversion strength (1.1, 0.2 to 2.1) but no difference in evertor strength, inversion joint position sense or peroneal latency in response to a perturbation. Conclusion There are specific impairments in people with recurrent ankle sprain but not necessarily in areas commonly investigated.

Intrinsic Predictors of Lateral Ankle Sprain in Adolescent Dancers: A Prospective Cohort Study

Objective:To identify intrinsic predictors of lateral ankle sprain. Design:Prospective cohort study. Setting:A performing arts secondary school and a dance school. Participants:One hundred fifteen adolescent dancers (94 female and 21 male) entered the study. One ankle of each dancer was randomly assigned to a test group (n = 114), and the other was assigned to a validation group (n = 112). Predictors:Eighteen measures, including age, dance history, previous ankle sprain, ankle and foot laxity and range of motion, and balance from test ankles were entered into a backwards stepwise Cox regression model. The model generated with the test group was used to predict ankle sprains in the validation group. Main Outcome Measure:Time to first lateral ankle sprain. Results:An increased risk of sprain in the test group was predicted by younger age [hazard ratio (HR) = 0.65, 95% CI 0.45-0.94], previous sprain of the contralateral ankle (HR = 3.76, CI 1.24-11.40), increased passive inversion range (HR = 1.06, CI 1.00-1.12), and inability to balance on demipointe (HR = 3.75, CI 1.02-13.73). Of these predictors, only previous sprain of the contralateral ankle significantly predicted ankle sprain in the validation group (HR = 3.90, CI 1.49-10.22). The predictive accuracy of this variable was not strong (positive likelihood ratio of 2.01 and negative likelihood ratio of 0.45). Conclusion:A history of previous lateral ankle sprain is associated with an increase in the risk of future sprain of the contralateral ankle.

Prevalence and impact of chronic musculoskeletal ankle disorders in the community.

OBJECTIVE To determine the point prevalence of chronic musculoskeletal ankle disorders in the community. DESIGN Cross-sectional stratified (metropolitan vs regional) random sample. SETTING General community. PARTICIPANTS Population-based computer-aided telephone survey of people (N=2078) aged 18 to 65 years in New South Wales, Australia. Of those contacted, 751 participants provided data. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Point prevalence for no history of ankle injury or chronic ankle problems (no ankle problems), history of ankle injury without residual problems, and chronic ankle disorders. Chronic musculoskeletal ankle disorders due to ankle sprain, fracture, arthritis, or other disorder compared by chi-square test for the presence of pain, weakness, giving way, swelling and instability, activity limitation, and health care use in the past year. RESULTS There were 231 (30.8%) participants with no ankle problems, 342 (45.5%) with a history of ankle injury but no chronic problems, and 178 (23.7%) with chronic ankle disorders. The major component of chronic ankle disorders was musculoskeletal disorders (n=147, 19.6% of the total sample), most of which were due to ankle injury (n=117, 15.6% of the total). There was no difference among the arthritis, fracture, sprain, and other groups in the prevalence of the specific complaints, or health care use. Significantly more participants with arthritis had to limit activity than in the sprain group (Chi-square test, P=.035). CONCLUSIONS Chronic musculoskeletal ankle disorders affected almost 20% of the Australian community. The majority were due to a previous ankle injury, and most people had to limit or change their physical activity because of the ankle disorder.

Sensorimotor Control Is Impaired in Dancers With Functional Ankle Instability

Background Factors potentially causing chronic instability after ankle inversion sprains have rarely been examined during the injuring movement. Purpose To compare control of ankle movement during quiet stance and after inversion perturbation in chronically unstable ankles (n = 16) with healthy controls (n = 26). Methods Movement control was measured as magnitude of lateral ankle oscillation, using 3SPACE Fastrak during single leg stance (baseline oscillation) in two foot positions, flat and demi-pointe. In both positions, time to resume baseline oscillation after inversion perturbation (perturbation time) of 15 ° for the flat foot and 7.5 ° on demi-pointe was also determined. Results Baseline oscillation on demi-pointe was significantly smaller (P < 0.005) for the sprained group (2.5 ± 0.5 mm) than for controls (4.0 ± 2.3 mm). Perturbation time for the flat foot was significantly longer (P < 0.05) for the sprained group (2.2 ± 0.4 seconds) than for controls (1.8 ± 0.5 seconds). However, failure rate was higher (P < 0.05) among the sprained group than controls for perturbation with the foot flat and baseline oscillation on demi-pointe. Conclusions Findings demonstrated altered sensorimotor control in chronically unstable ankles. Those sprainers who successfully completed the tasks minimized oscillation. The impairments in the sprained group may reflect deficits in either movement detection, peroneal muscle response, or both.

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.

Balance and recovery from a perturbation are impaired in people with functional ankle instability

Objective:To determine if differences in balance and recovery would be found between controls and participants with unilateral or bilateral functional ankle instability (FAI). Design:Cross-Sectional Study. Setting:University laboratory and Community premises. Participants:Twenty healthy participants(C), 19 participants with unilateral FAI [both the uninjured (UC) and unstable ankle (UI) were included] and 22 participants with bilateral FAI (BI). Main Outcome Measures:Balance was measured in single leg stance as: number of part foot lifts in 30 s; magnitude of medio-lateral ankle movement in two foot positions; and ability to balance on the ball of the foot. Recovery was determined by time to return to baseline medio-lateral ankle movement after a 15 degree inversion perturbation. Results:The controls lifted the foot fewer times than the other three groups [C = 12.7 ± 1.8 (mean ± SE) foot lifts, UC = 22.9 ± 2.5, UI = 25.1 ± 2.3, and BI = 21.1 ± 2.2, t-test, P = 0.006] and recovered significantly faster than the unstable ankles [C = 1.53 ± 0.42 sec (median ± SE), UI = 2.34 ± 0.30 sec, BI = 2.15 ± 0.70 sec, P < 0.02]. With FAI measured by the Cumberland Ankle Instability Tool, the external control group balanced on demi-pointe better than both instability groups (P < 0.05), and recovered quicker than all groups. Conclusion:There are differences in balance and recovery between external controls and participants with both unilateral and bilateral FAI but not between the legs of participants with unilateral FAI.

The effect of ankle taping or bracing on proprioception in functional ankle instability: A systematic review and meta-analysis

OBJECTIVES To determine if wearing an ankle brace or taping the ankle, compared to no brace or tape, improves proprioceptive acuity in people with a history of ankle sprain or functional ankle instability. DESIGN Systematic review and meta-analysis. METHODS Studies using controlled, cross-over designs whereby participants who had sprained their ankle at least once or had functional ankle instability, underwent some form of proprioceptive sensation testing with and without ankle brace or tape, were included. Proprioceptive acuity was reported for the ankle tape/brace condition and the condition where no tape or brace was worn. Meta-analysis was employed to compare proprioceptive acuity with and without ankle tape/brace. RESULTS Eight studies were included in the review. Studies measured either sense of movement or sense of joint position. The mean differences in 19 of 32 comparisons were not significant. Of the remaining mean differences, 10 were positive, indicating better proprioceptive acuity in the taped/braced condition and 3 were negative, indicating poorer proprioceptive acuity. Overall, there was no significant effect with ankle tape/brace compared to the no tape/brace condition (mean difference: 0.08°, 95% CI: -0.39 to 0.55). This finding was consistent when the two aspects of proprioception (sense of movement or joint position) were considered separately. CONCLUSIONS The pooled evidence suggests that using an ankle brace or ankle tape has no effect on proprioceptive acuity in participants with recurrent ankle sprain or who have functional ankle instability.

Evidence review for the 2016 International Ankle Consortium consensus statement on the prevalence, impact and long-term consequences of lateral ankle sprains.

Lateral ankle sprains (LASs) are the most prevalent musculoskeletal injury in physically active populations. They also have a high prevalence in the general population and pose a substantial healthcare burden. The recurrence rates of LASs are high, leading to a large percentage of patients with LAS developing chronic ankle instability. This chronicity is associated with decreased physical activity levels and quality of life and associates with increasing rates of post-traumatic ankle osteoarthritis, all of which generate financial costs that are larger than many have realised. The literature review that follows expands this paradigm and introduces emerging areas that should be prioritised for continued research, supporting a companion position statement paper that proposes recommendations for using this summary of information, and needs for specific future research.