Carrie L. Docherty

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.

Arthrogenic Muscle Inhibition in the Leg Muscles of Subjects Exhibiting Functional Ankle Instability

Background: Functional ankle instability or a subjective report of “giving way” at the ankle may be present in up to 40% of patients after a lateral ankle sprain. Damage to mechanoreceptors within the lateral ankle ligaments after injury is hypothesized to interrupt neurologic feedback mechanisms resulting in functional ankle instability. The altered input can lead to weakness of muscles surrounding a joint, or arthrogenic muscle inhibition. Arthrogenic muscle inhibition may be the underlying cause of functional ankle instability. Establishing the involvement of arthrogenic muscle inhibition in functional ankle instability is critical to understanding the underlying mechanisms or chronic ankle instability. The purpose of this investigation was to determine if arthrogenic muscle inhibition is present in the ankle joint musculature of patients exhibiting unilateral functional ankle instability. Methods: Twenty-nine subjects, 15 with unilateral functional ankle instability and 14 healthy control subjects, consented to participate. Bilateral soleus, peroneal, and tibialis anterior H-reflex and M-wave recruitment curves were obtained. Maximal H-reflex and maximal M-wave values were identified and the H:M ratios were calculated for data analysis. Separate 1 × 2 ANOVA were done for both the functional ankle instability and control groups to evaluate differences between limbs on the H:M ratios. Bonferroni multiple comparison procedures were used for post hoc comparisons (p ≤ 0.05). Results: The soleus and peroneal H:M ratios for subjects with functional ankle instability were smaller in the injured limb when compared with the uninjured limb (p < 0.05). No limb difference was detected for the tibialis anterior H:M ratio in the functional ankle instability group (p = 0.904). No side-to-side differences were detected for the H:M ratios in patients reporting no history of ankle injury (p > 0.05). Conclusions: Depressed H:M ratios in the injured limb suggest that arthrogenic muscle inhibition is present in the ankle musculature of patients exhibiting functional ankle instability. Establishing and using therapeutic techniques to reverse arthrogenic muscle inhibition may reduce the incidence of functional ankle instability.

Force sense deficits in functionally unstable ankles

The purpose of this study was to determine whether participants with functional ankle instability have deficits in force sense reproduction compared to uninjured participants. Twenty participants with no history of injury and 20 with functional ankle instability volunteered for this investigation. Participants in the instability group had a history of at least one ankle sprain and frequent episodes of giving way. Ankle force sense testing was performed at 10, 20, and 30% of eversion maximal voluntary isometric contraction. Ten trials were performed at each force. Absolute and variable errors were then calculated. We observed significant (p < 0.05) main effects for group for absolute and variable errors. Force sense absolute error was significantly greater in the functionally unstable ankles (3.7 ± 2.2 N) compared to uninjured ankles (2.8 ± 1.1 N). Variable error was also significantly greater in the functionally unstable ankles (3.2 ± 1.8 N) than the uninjured ankles (2.4 ± 0.8 N). Functional ankle instability is associated with deficits in an individuals ability to accurately reproduce a given force. This deficit may impair an individuals ability to set appropriate muscle force levels to provide stability to the joint.

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.

Development of the Identification of Functional Ankle Instability (IdFAI)

Background: Self-reported questionnaires are a common method used in identifying individuals with ankle instability. Recently a study illustrated the singular use of any of the most frequently utilized questionnaires failed to significantly predict ankle stability status. Therefore, the purpose of this article was to present information related to the development of the Identification of Functional Ankle Instability (IdFAI). Methods: Volunteers (n = 278; 125 males, 153 females, 19.8 ± 1.4 years) completed the IdFAI on one occasion. An exploratory factor analysis was conducted with principal axis factoring as the extraction method with varimax rotation. Additionally, a discriminant function analysis was conducted to identify a discrimination score and to evaluate the accuracy of the questionnaire. Results: The factor analysis revealed: factor 1 (four questions) explained 53.7% of the variance, factor 2 (four questions) with an additional 17.4%, and factor 3 (two questions) an additional 6.3%. Overall, these factors accounted for 77.4% of the variance. There was a distinct discrimination score of 10.3 to identify people who have the minimally accepted criteria for FAI. Overall, the IdFAI has an accuracy of 89.6%. Conclusion: This investigation showed that the IdFAI was a feasible and appropriate way to identify individuals with FAI. Clinical Relevance: We suggest clinicians and researchers utilize the IdFAI to identify individuals with functional ankle instability since it is a short, simple, easy questionnaire to administer and take, and has been shown to have excellent accuracy.

Critical review of self-reported functional ankle instability measures.

Background: Since functional ankle instability (FAI) lacks a “gold standard” measure, a variety of self-reported ankle instability measures have been created. The purpose of this study was to determine which ankle instability measure identifies individuals who meet a minimum acceptable criterion for FAI. Methods: Participants volunteered from a large university population which included 242 participants (104 males, 138 females; 21.4 ± 1.4 years). The predictor variables were seven ankle instability questionnaires: Ankle Instability Instrument (AII), Ankle Joint Functional Assessment Tool (AJFAT), Chronic Ankle Instability Scale (CAIS), Cumberland Ankle Instability Tool (CAIT), Foot and Ankle Ability Measure (FAAM), Foot and Ankle Instability Questionnaire (FAIQ), and Foot and Ankle Outcome Score (FAOS). The outcome variable (MC_FAI) was created based on the minimum acceptable criteria for FAI. This was established as at least one ankle sprain and an episode of giving way. Data were modeled using chi-square and multinomial logistic regression. Results: The regression model revealed all of the questionnaires were more useful at identifying participants who did not meet the minimum criteria for FAI (No MC_FAI = 95.7%, MC_FAI = 55.6%, overall = 84.6%). Based on the Wald criterion, the full model was reduced to the CAIT, AII, and FAAM. The reduced model revealed the CAIT (X 2 = 8.756, p = 0.003) and AII (X 2 = 31.992, p = 0.001) as the only variables that had a significant relationship with the outcome variable. Conclusion: The model illustrates no single measure was able to predict if individuals met the minimally accepted criteria for FAI. However, a significantly accurate prediction of ankle stability status was produced by combining the CAIT and AII. Clinical Relevance: Based on the results we recommend that researchers and clinicians use both the CAIT and AII to determine ankle stability status.

The Ability of 4 Single-Limb Hopping Tests to Detect Functional Performance Deficits in Individuals With Functional Ankle Instability

STUDY DESIGN Experimental laboratory testing using a cross-sectional design. OBJECTIVES To determine if functional performance deficits are present in individuals with functional ankle instability (FAI) in 4 single-limb hopping tests, including figure-of-8 hop, side hop, 6-meter crossover hop, and square hop. BACKGROUND Conflicting results exist regarding the presence of functional deficits in individuals with FAI. It is important to evaluate whether functional performance deficits are present in this population, as well as if subjective feelings of giving way can assist in identifying these deficits. METHODS Sixty college students volunteered for this study. Thirty participants with unilateral ankle instability were placed in the FAI group and 30 participants with no history of ankle injuries were placed in the control group. The FAI group was subsequently further divided to indicate those that reported giving way during the functional test (FAI-GW) and those that did not (FAI-NGW). Time to complete each test was recorded and the mean of 3 trials for each test were used for statistical analysis. To identify performance differences, we used 4 mixed-design 2-way (side-by-group) ANOVAs, 1 for each hop test. A Tukey post hoc test was completed on all significant findings. RESULTS We identified a significant side-by-group interaction for all 4 functional performance tests (P<.05). Specifically, for each functional performance test, the FAI limb performed significantly worse than the contralateral uninjured limb in the FAI-GW group. Additionally, the FAI limb in the FAI-GW group performed worse than the FAI limb in the FAI-NGW group, and the matched limb in the control group in 3 of the 4 functional performance tests. CONCLUSION We found that functional performance deficits were present in participants with FAI who also experienced instability during the test. This difference was identified when comparing the FAI limb to the contralateral uninjured limb as well as control participants. However, the performance deficits identified in this study were relatively small. Future research in this area is needed to further evaluate the clinical meaningfulness of these findings. Finally, we found that limb dominance did not affect performance.

Differences in Ankle Range of Motion Before and After Exercise in 2 Tape Conditions

Background Athletic tape has been used on the ankle to decrease range of motion and to prevent injuries. Results from previous research found that with physical exercise athletic tape loses some of its restricting properties; recently, a new self-adherent taping product was developed that may restrict range of motion regardless of exercise. Hypothesis Self-adherent tape will maintain ankle range of motion restriction more than traditional white cloth tape both before and after activity. Study Design Controlled laboratory study. Methods Twenty volunteers participated in testing procedures on 3 separate days, 1 for each taping condition (self-adherent, white cloth, and no tape). The participants ankle range of motion was measured with an electrogoniometer before application of the tape, immediately after application of the tape, and after 30 minutes of physical exercise. Range of motion was measured in 2 planes of motion: inversion to eversion and dorsiflexion to plantar flexion. Results White cloth tape and self-adherent tape both restricted inversion to eversion range of motion immediately after application, but with 30 minutes of exercise only the self-adherent tape maintained the decreased range of motion. For dorsiflexion to plantar flexion range of motion, the white tape and self-adherent tape both significantly decreased range of motion immediately after application and after the exercise protocol. Conclusions and Clinical Relevance The self-adherent tape maintained range of motion restriction both before and after exercise. Conversely, the white cloth tape lost some of its restrictive properties after 30 minutes of exercise.

Current Health-Related Quality of Life Is Lower in Former Division I Collegiate Athletes Than in Non–Collegiate Athletes:

Background: College athletes participate in physical activity that may increase chronic stress and injury and induce overtraining. However, there is little known about how previous injuries that have occurred during college may limit current physical activity and/or decrease their subsequent health-related quality of life (HRQoL). Purpose: To evaluate HRQoL in former United States National Collegiate Athletic Association Division I athletes and nonathletes with the Patient-Reported Outcomes Measurement Information System (PROMIS) and a demographics questionnaire. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: The study sample was recruited through alumni databases at a large Midwestern university and consisted of 2 cohorts: (1) former Division I athletes and (2) nonathletes who participated in recreational activity, club sports, or intramurals while attending college. Participants answered a survey constructed with a web-based system. All individuals contacted were between the ages of 40 and 65 years. Study participants responded to the questions on the PROMIS scales for sleep, anxiety, depression, fatigue, pain interference, physical function, and satisfaction with participation in social roles. The PROMIS was developed to fill the void of HRQoL being evaluated by multiple instruments. An additional questionnaire was constructed to record demographic and exercise information. Results: Initially, 1280 former Division I athletes and nonathletes were contacted; 638 surveys were returned (49.8%). Surveys eligible for analyses (71.6%) were completed by 232 former Division I athletes (mean age ± SD, 53.36 ± 7.11 years) and 225 nonathletes (mean age ± SD, 53.60 ± 6.79 years). Univariate analyses for the effect of group was significantly related to PROMIS scales for physical function, depression, fatigue, sleep disturbances, and pain interference (P < .05). The overall scores were significantly worse for the former Division I athletes than for the nonathletes on 5 of the 7 scales. In addition, the former Division I athletes reported significantly more limitations in daily activities and more major and chronic injuries than did the nonathlete controls. Conclusion: According to these data, former Division I athletes have decreased HRQoL compared with nonathletes. Clinical Relevance: Sports encourage physical activity, which help promote a healthy lifestyle. Moderate activity and exercise should be encouraged. However, the demands of Division I athletics may result in injuries that linger into adulthood and possibly make participants incapable of staying active as they age, thereby lowering their HRQoL.

2016 consensus statement of the International Ankle Consortium: prevalence, impact and long-term consequences of lateral ankle sprains

The Executive Committee of the International Ankle Consortium presents this 2016 position paper with recommendations for information implementation and continued research based on the paradigm that lateral ankle sprain (LAS), and the development of chronic ankle instability (CAI), serve as a conduit to a significant global healthcare burden. We intend our recommendations to serve as a mechanism to promote efforts to improve prevention and early management of LAS. We believe this will reduce the prevalence of CAI and associated sequelae that have led to the broader public health burdens of decreased physical activity and early onset ankle joint post-traumatic osteoarthritis. Ultimately, this can contribute to healthier lifestyles and promotion of physical activity.