Recurrent Ankle Sprains Research Articles

Bracing superior to neuromuscular training for the prevention of self-reported recurrent ankle sprains: a three-arm randomised controlled trial

BackgroundAnkle sprain is the most common sports-related injury with a high rate of recurrence and associated costs. Recent studies have emphasised the effectiveness of both neuromuscular training and bracing for...

The implementation effectiveness of the ‘Strengthen your ankle’ smartphone application for the prevention of ankle sprains: design of a randomized controlled trial

BackgroundAnkle sprains continue to pose a significant burden to the individual athlete, as well as to society as a whole. However, despite ankle sprains being the single most common sports injury and despite an active approach by various Dutch organisations in implementing preventive measures, large-scale community uptake of these preventive measures, and thus actual prevention of ankle sprains, is lagging well behind. In an attempt to bridge this implementation gap, the Dutch Consumer Safety Institute VeiligheidNL developed a freely available interactive App (‘Strenghten your ankle’ translated in Dutch as: ‘Versterk je enkel; available for iOS and Android) that contains - next to general advice on bracing and taping - a proven cost-effective neuromuscular program. The ‘Strengthen your ankle’ App has not been evaluated against the ‘regular’ prevention approach in which the neuromuscular program is advocated through written material. The aim of the current project is to evaluate the implementation value of the ‘Strengthen your ankle’ App as compared to the usual practice of providing injured athletes with written materials. In addition, as a secondary outcome measure, the cost-effectiveness will be assessed against usual practice.Methods/DesignThe proposed study will be a randomised controlled trial. After stratification for medical caregiver, athletes will be randomised to two study groups. One group will receive a standardized eight-week proprioceptive training program that has proven to be cost-effective to prevent recurrent ankle injuries, consisting of a balance board (machU/ MSG Europe BVBA), and a traditional instructional booklet. The other group will receive the same exercise program and balance board. However, for this group the instructional booklet is exchanged by the interactive ‘Strengthen your ankle’ App.DiscussionThis trial is the first randomized controlled trial to study the implementation effectiveness of an App for proprioceptive balance board training program in comparison to a traditional printed instruction booklet, with the recurrence of ankle sprains among athletes as study outcome. Results of this study could possibly lead to changes in practical guidelines on the treatment of ankle sprains and in the use of mobile applications for injury prevention. Results will become available in 2014.Trial registrationThe Netherlands National Trial Register NTR4027. The NTR is part of the WHO Primary Registries.

People with recurrent ankle sprains do not change their ankle strategy in anticipation of a perturbation event

Methods Two groups of participants were recruited: 14 with no history of ankle injury (age 22.6 ± 0.7 yrs, 10 females) and 14 with a history of two or more ankle sprains (Age 21.1 ± 0.2 yrs, 9 females, 6 ± 2.5 sprains). Participants stood in single leg stance on an inversion perturbation platform. The perturbation platform dropped 15 degrees in the frontal plane on a trigger activated by the researcher. Movement Oscillation at the ankle was measured via a 3Space fastrak (Polhemius Ltd) with a receiver taped one cm above the lateral malleolus. Oscillation was determined as the standard deviation of the movement in the frontal plane (mm) measured over 10s while the platform was horizontal. Three conditions were investigated: standing with no change in the platform, standing with a 15 deg drop occurring at a specified time, and standing with a drop occurring at anytime. Data were compared between groups using a Mann-Whitney U test, as the data were not normally distributed.

Systematic review of chronic ankle instability in children.

BackgroundChronic ankle instability (CAI) is a disabling condition often encountered after ankle injury. Three main components of CAI exist; perceived instability; mechanical instability (increased ankle ligament laxity); and recurrent sprain. Literature evaluating CAI has been heavily focused on adults, with little attention to CAI in children. Hence, the objective of this study was to systematically review the prevalence of CAI in children.MethodsStudies were retrieved from major databases from earliest records to March 2013. References from identified articles were also examined. Studies involving participants with CAI, classified by authors as children, were considered for inclusion. Papers investigating traumatic instability or instability arising from fractures were excluded. Two independent examiners undertook all stages of screening, data extraction and methodological quality assessments. Screening discrepancies were resolved by reaching consensus.ResultsFollowing the removal of duplicates, 14,263 papers were screened for eligibility against inclusion and exclusion criteria. Nine full papers were included in the review. Symptoms of CAI evaluated included perceived and mechanical ankle instability along with recurrent ankle sprain. In children with a history of ankle sprain, perceived instability was reported in 23-71% whilst mechanical instability was found in 18-47% of children. A history of recurrent ankle sprain was found in 22% of children.ConclusionDue to the long-lasting impacts of CAI, future research into the measurement and incidence of ankle instability in children is recommended.

Chronic complaints after ankle sprains: a systematic review on effectiveness of treatments.

Systematic review. Objective To determine the effectiveness of treatments for patients with chronic complaints after ankle sprain. Though most people recover completely after a lateral inversion ankle injury, a considerable percentage have persistent complaints. Currently, it is still unclear which treatment options are best for these patients. Major databases, including PubMed, Embase, CINAHL, and PEDro, were searched for randomized controlled trials and controlled clinical trials conducted from 1966 to October 2012. Due to clinical heterogeneity, the data were analyzed using a best-evidence synthesis. A total of 20 randomized controlled trials and 1 controlled clinical trial were included in the analysis. The included studies compared different treatments (training programs, physiotherapy, chiropractic/manual therapy, surgery, postoperative training, and functional treatment). For pain and function outcomes, limited to moderate evidence was found for effectiveness of a training program compared to conservative treatment. Two studies found a decrease of recurrences after a proprioceptive training program. Four studies showed good results for different surgical methods but did not include a nonsurgical control group for comparison. Limited evidence was found for the effectiveness of an early mobilization program after surgery. In chronic ankle complaints after an ankle sprain, a training program gives better results for pain and function, and a decrease of recurrent ankle sprains, than a wait-and-see policy. There was insufficient evidence to determine the most effective surgical treatment, but limited evidence suggests that postoperative, early mobilization was more effective than a plaster cast. Therapy, level 1a-.

Number of previous ankle sprains a latent risk factor for recurrent ankle sprain in young soccer players

Number of previous ankle sprains a latent risk factor for recurrent ankle sprain in young soccer players

Impact of Combined Muscle Strength and Proprioceptive Exercises on Functional Ankle Instability

Ankle sprain accounts for 7–10% of cases admittedto the emergency room in hospitals(1). According tostudies, ankle sprain accounts for 15–20% of allsports-related injuries(2, 3). The ratio of reoccur-rence of ankle sprain is reported to be as high as30–40%(4).Functional ankle instability(FAI) refers to the sub -jective feeling of an ankle giving way that remainsafter recurrent ankle sprains(5). The Cumberlandankle instability tool(CAIT) can be used to evaluateFAI. This evaluation tool has high reliability andvalidity(6). Isokinetic equipment evaluates muscle functionalitythrough peak torque, peak torque % bodyweight(PT%BW), average power, and total work.Isokinetic equipment has been used as a standardevaluation instrument(7, 8, 9). It is also utilized in avariety of areas due to its high reliability(10, 11). Causes of FAI include muscle weakening and lackof proprioceptive senses. Proprioception plays animportant role in neuromuscular interactions(12).These deliver various kinds of signals to the centralnervous system through the muscle spindle andGolgi tendon organ located in ligaments, skin, mus -cles, tendons, and joint capsules to control themovement of the body(12). Previous studies have examined the use of muscle-strengthening exercises, as well as exercises thatimprove proprioceptive sense and FAI(13, 14). Ankleinstability is caused not only by deficiency of musclestrength but also by a lack of proprioception at thesame time(15, 16, 17). Thus, execution of muscle-strengthening exercise and proprioceptive senseexercise separately may be ineffective interventionsfor FAI. Therefore, the current study implemented a combi-nation of muscle-strengthening and proprioceptivesense exercises and examined the impacts of thesecombined exercises on FAI.

Minimum Reporting Standards for Copers in Chronic Ankle Instability Research

Lateral ankle sprains (LASs) are among the most common sports-related injuries and a high percentage of individuals who sprain their ankle go on to develop chronic ankle instability (CAI). The condition of CAI is often classified as having pain, loss of function, and a restriction of, or failure to, return to levels of previous activity. Historically, uninjured healthy controls are used as a comparison group to study the biomechanical and neuromuscular consequences of CAI. However, this model is not ideal to determine why a portion of the population experiencing an ankle sprain does not recover. A more appropriate comparison may be individuals who had an ankle sprain, and thus the exposure, but did not go on to develop CAI (i.e., copers). Thus, the purpose of this review was to determine the existing discrepancies and common standards in definitions of, terminology used for, and the inclusionary/exclusionary criteria used to describe copers within the CAI literature. Multiple databases were searched by keywords and specific authors. Potential studies were screened independently by both authors. Inclusion criteria consisted of an explicit definition of copers and explicit inclusionary/exclusionary criteria. A total of 21 studies were included in the current study and had four outcomes extracted: (1) the definition of copers; (2) the terminology used; (3) specific inclusionary/exclusionary criteria; and (4) injury characteristics of the copers. Based on the included operational definitions, it is recommend that future operational definitions of copers include three key components: (1) an initial LAS; (2) subsequent lack of CAI symptoms (i.e., no complaints of disability or giving way); and (3) a time since injury component. The term coper was overwhelming used within the existing literature (n = 15) and is thus recommended to be used in future studies when describing individuals who have suffered an LAS but failed to develop CAI. Minimal inclusionary criteria should consist of three things: (1) an initial LAS severe enough to warrant either the use of a protective device (e.g., ankle brace) for at least 1 week or immobilization and/or non-weight bearing for at least 3 days, or both; (2) a return to at least moderate levels of weight-bearing physical activity for at least 12 months without recurrent injury, episodes of giving way, and/or feelings of instability; and (3) minimal, if any, level of self-reported disability. Acute head and/or lower extremity injuries that occurred ≤3 months prior to testing, a history of ankle fractures and/or surgeries, and the presence of pain (constant or intermittent) should be used as minimal exclusionary criteria in future investigations dealing with copers. Finally, at least seven items should be reported to better contextualize copers across investigations. These items should include the initial mechanism of injury, the presence of mechanical laxity, number of days immobilized and/or non-weight bearing after the initial ankle sprain, time since the latest ankle sprain, percentage of coper participants with a recurrent ankle sprain or giving way episode, current physical activity levels, and whether copers attended formal rehabilitation for their involved ankle.

Mechanical instability destabilises the ankle joint directly in the ankle-sprain mechanism

BackgroundDespite massive research efforts, it remains unclear how mechanical ankle instability (MAI) and functional ankle instability (FAI) affect joint control in the situation of ankle sprain. Thus, the purpose of...

The role of 6-week hydrotherapy and land-based therapy plus ankle taping in a preseason rehabilitation program for athletes with chronic ankle instability

Background: Many athletes, especially at elite university level, suffer from chronic ankle instability (CAI). Chronic ankle instability usually occurs after simple ankle sprain from poor landing. The repetitive injury causes chronic ankle instability. This chronic ankle instability leads to poor performance and recurrent injury during training and competition. A proper rehabilitation program may improve performance and prevent further injury. Objectives: We aimed to compare the effect of a 6-week functional rehabilitation program in athletes with chronic ankle instability between a hydrotherapy plus ankle taping group and a land-based plus ankle taping group on ankle functional ability, ankle joint position sense and the number of reinjuries. Methods: Forty-seven university level athletes with chronic ankle instability and residual symptoms were randomized into a hydrotherapy group (24 participants) and a land-based group (23 participants). All participants were taped using a heel lock technique at the injured ankle during the training session. The rehabilitation program included stretching, aerobic exercise, balance exercise, strengthening exercise, and skill training using an aquatic or land-based environment according to the group for 6 weeks. A single-limb hopping test and ankle joint position sense were measured at baseline, 6 weeks, and 3 months. Recurrent ankle injuries were also recorded. Results: In the hydrotherapy group, the time taken in the single-limb hopping test significantly decreased immediately after exercise and at the follow up compared with baseline (p = 0.001). In the land-based group, time taken in the single-limb hopping test significantly decreased at 3 months follow up compared with baseline (p = 0.05). No significant differences were detected between groups in ankle joint position sense and the number of recurrent ankle sprains. All participants returned to their athletic activity and competition. Conclusion: The combined rehabilitation program of ankle taping, land-based exercise and/or hydrotherapy could be recommended for clinical uses in athletes with chronic ankle instability.

Therapeutic Interventions for Increasing Ankle Dorsiflexion After Ankle Sprain: A Systematic Review

Clinicians perform therapeutic interventions, such as stretching, manual therapy, electrotherapy, ultrasound, and exercises, to increase ankle dorsiflexion. However, authors of previous studies have not determined which intervention or combination of interventions is most effective. To determine the magnitude of therapeutic intervention effects on and the most effective therapeutic interventions for restoring normal ankle dorsiflexion after ankle sprain. We performed a comprehensive literature search in Web of Science and EBSCO HOST from 1965 to May 29, 2011, with 19 search terms related to ankle sprain, dorsiflexion, and intervention and by cross-referencing pertinent articles. Eligible studies had to be written in English and include the means and standard deviations of both pretreatment and posttreatment in patients with acute, subacute, or chronic ankle sprains. Outcomes of interest included various joint mobilizations, stretching, local vibration, hyperbaric oxygen therapy, electrical stimulation, and mental-relaxation interventions. We extracted data on dorsiflexion improvements among various therapeutic applications by calculating Cohen d effect sizes with associated 95% confidence intervals (CIs) and evaluated the methodologic quality using the Physiotherapy Evidence Database (PEDro) scale. In total, 9 studies (PEDro score = 5.22 ± 1.92) met the inclusion criteria. Static-stretching interventions with a home exercise program had the strongest effects on increasing dorsiflexion in patients 2 weeks after acute ankle sprains (Cohen d = 1.06; 95% CI = 0.12, 2.42). The range of effect sizes for movement with mobilization on ankle dorsiflexion among individuals with recurrent ankle sprains was small (Cohen d range = 0.14 to 0.39). Static-stretching intervention as a part of standardized care yielded the strongest effects on dorsiflexion after acute ankle sprains. The existing evidence suggests that clinicians need to consider what may be the limiting factor of ankle dorsiflexion to select the most appropriate treatments and interventions. Investigators should examine the relationship between improvements in dorsiflexion and patient progress using measures of patient self-reported functional outcome after therapeutic interventions to determine the most appropriate forms of therapeutic interventions to address ankle-dorsiflexion limitation.

Interest of rehabilitation in healing and preventing recurrence of ankle sprains

To assess the impact of rehabilitation on healing and recurrence rate of ankle sprain, 1year apart, 111 patients, who suffered an ankle sprain (67 men and 44 women; 17 mild sprains, 67 medium and 27 severe), were included by emergency physicians of four emergency rooms (ER) of Finistère. The physician was free to prescribe, or not, further investigations. He prescribed systematically to patients RICE (rest, ice, compression, elevation) protocol, put an ankle brace, and gave a prescription of standardized rehabilitation. The prescription was the same for the four ER. All patients were recalled to 1year. Of the 111 patients initially included, 21 patients were excluded for lack of response after three phone calls. In the end, 90 patients were assessable (56 men and 34 women), mean age 31.4±12.6years (range 15–55) at the time of initial trauma. Emergency physicians had diagnosed, initially, 16 mild sprains (17.8%), 56 medium sprains (62.2%) and 18 severe sprains (20%). Of the 90 patients, 73 patients have been rehabilitated (81.1%). Of the 44 accidents of everyday life, 31 were rehabilitated (70.5%). Of the 27 sports accidents, 25 were rehabilitated (92.6%). Of the 19 work-related injuries, 17 were rehabilitated (89.5%). There is no significant relationship between rehabilitation and no recurrence (P=0.45) nor between rehabilitation and full recovery of the ankle (P=0.59). Conclusion: We find no association between rehabilitation and prevention of recurrence, nor between rehabilitation and healing of patients. However, our study is limited by the small size of the non-rehabilitated group.

O Contributo do Conhecimento Fundamental na Prevenção e Tratamento de Lesões: o Exemplo das Entorses do Tornozelo

Over the years a number of high quality studies has established the effectiveness of external measures (tape, brace) and neuromuscular training for the prevention of ankle sprains. The general conclusion derived from these studies is that recurrent ankle sprains can be effectively prevented using any of these measures, and that measures are cost-beneficial. Nevertheless, despite the commonness of this type of injury and the availability of effective measures, implementation of prevention in clinical practice is lagging behind. In addition, although proven effective, a link between biomechanical and neurophysiological adaptations as a function of preventive measures, leading to clinical and functional improvements and ultimately ankle sprain recurrence prevention, has never been fully made. The current evidence on ankle sprains and their prevention provides ample opportunities to pursue a translational approach through which fundamental knowledge will provide guidance to specify the effective preventive program to its bare essentials and decrease user-burden while retaining full effectiveness.

Return-to-play probabilities following new versus recurrent ankle sprains in high school athletes

Although ankle sprains have the highest recurrence rate of any musculoskeletal injury, objective estimates of when an athlete is likely to return-to-play (RTP) are unknown. The purpose was to compare time to return-to-play probability timelines for new and recurrent ankle sprains in interscholastic athletes. Observational. Ankle sprain data were collected at seven high schools during the 2007-2008 and 2008-2009 academic years. Ankle sprains were categorized by time lost from participation (same day return, next-day return, 3-day return, 7-day return, 10-day return, >22-day return, no return [censored data]). Time-to-event analyses were used to determine the influence of ankle injury history on return-to-play after an ankle sprain. 204 ankle sprains occurred during 479,668 athlete-exposures, 163 were new (4 censored) and 35 recurrent (1 censored). There was no significant difference (p=0.89) between the time-to-event curves for new and recurrent ankle sprains. The median (inter-quartile rage) time to return-to-play for new sprains (inter-quartile range)=3 days (same day to 7 day return); recurrent sprains=next day return (next day to 7 day return). Noteworthy probabilities [95% CIs] include: same day return (new=25.2[18.7, 31.9], recurrent=17.1[6.6, 30.3]); next-day return (new=43.6[35.3, 52.7], recurrent=51.4[32.5, 67.5]); and 7-day return (new=85.9[73.8, 94.4], recurrent=94.3[47.8, 99.5]). Previous injury history did not affect time until return-to-play probabilities for ankle sprains. Time until return-to-play analyses that describe the likelihood of return-to-play are useful to clinicians by providing prognostic guidelines and can be used for educating athletes, coaches, and parents about the likely timeframe of being withheld from play.

Foot Overuse Diseases in Rock Climbing

Literature examining the incidence of foot diseases in rock climbing is limited to traumatic injuries. We examined a large sample of climbers, assessed the chronic diseases of the foot, and correlated them with foot morphology, shoe type, and type of climbing practiced. Between May 1 and September 30, 2009, 144 climbers (mean age, 31.7 years) were examined to analyze the effect of rock climbing on the various foot diseases found at the time of the evaluation. Eighty-six percent of the climbers were affected by a pathologic condition. Nail disease was found in 65.3% of patients, followed by recurrent ankle sprains (27.8%), retrocalcaneal bursitis (19.4%), Achilles tendinitis (12.5%), metatarsalgia (12.5%), and plantar fasciitis (5.6%). Male sex, the use of high-type shoes, the high degree of climbing difficulty, and the competitive level were often related to the onset of foot diseases. Climbing shoes are usually smaller than common footwear. This "shoe-size reduction" averaged 2.3 sizes, forcing the foot into a supinated and cavus posture that favors lateral instability. The posterior edge of the shoe aperture produces increased pressure on the heel, with retrocalcaneal bursitis. Overuse foot diseases related to rock climbing are particularly frequent and debilitating. Detailed knowledge of these diseases and their predisposing factors may help us implement effective preventive or therapeutic measures, including changes in the type of climbing, correction of body weight, degree of difficulty, footwear, orthoses, and measures that maximize the support of the foot to the ground.

Effect of Balance Training after Lateral Ankle Sprain in High School Male Athletes between the Ages 15-18 Years

Purpose: To determine the effect of balance training in high school athletes after lateral ankle sprains. Subject: 60 male subjects aged 15-18 years Methods: 60 high school male athletes in the age group of 15-18 years with lateral ankle sprain were assigned to training. Subjects of training group participated in a 4(four) week balance training program based on a compilation of the rehabilitation and balance validated and published in prior studies. SEBT and CAIT score were taken to measure severity of functional ankle stability during pre - and post- balance training programme. Result: After balance training ,significant differences were found in reach distance of SEBT score in Anterior(A), Lateral(L), Medial(M), Anteromedial(AM), Anterolateral(AL), Posteromedial (PM) and Posterolateral(PL); whereas the reach distance in posterior(P) direction showed insignificant difference. Significant difference was noted in the post-training CAIT score Conclusion: Balance training program significantly reduces the risk of recurrent ankle sprains in high school athletes with lateral ankle sprain.

The prevention of injuries in contact flag football

American flag football is a non-tackle, contact sport with many moderate to severe contact-type injuries reported. A previous prospective injury surveillance study by the authors revealed a high incidence of injuries to the fingers, face, knee, shoulder and ankle. The objectives of the study were to conduct a pilot-prospective injury prevention study in an attempt to significantly reduce the incidence and the severity of injuries as compared to a historical cohort, as well as to provide recommendations for a future prospective injury prevention study. A prospective injury prevention study was conducted involving 724 amateur male (mean age: 20.0 ± 3.1 years) and 114 female (mean age: 21.2 ± 7.2 years) players. Four prevention measures were implemented: the no-pocket rule, self-fitting mouth guards, ankle braces (for those players with recurrent ankle sprains) and an injury treatment information brochure. An injury surveillance questionnaire was administered to record all time-loss injuries sustained in game sessions. There was a statistically significant reduction in the number of injured players, the number of finger/hand injuries, the incidence rate and the incidence proportion between the two cohorts (p < 0.05). This one-season pilot prevention study has provided preliminary evidence that finger/hand injuries can be significantly reduced in flag football. Prevention strategies for a longer, prospective, randomised-controlled injury prevention study should include the strict enforcement of the no-pocket rule, appropriate head gear, the use of comfortable-fitting ankle braces and mouth guards, and changing the blocking rules of the game.

A New Paradigm for Rehabilitation of Patients with Chronic Ankle Instability

Lateral ankle sprains have been shown to be one of the most common musculoskeletal injuries in both athletes and the recreationally active population. Moreover, it is estimated that approximately 30% of people who incur a lateral ankle sprain will ssustain recurrent ankle sprains and experience symptoms of pain and instability that last > 1 year. Chronic ankle instability (CAI) is the term used to describe cases involving repetitive ankle sprains, multiple episodes of the ankle “giving way,“ persistent symptoms, and diminished self-reported function for > 1 year after the initial ankle sprain. The optimal conservative treatment for CAI is yet to be determined; however, comparison between patients with CAI and individuals showing no history of ankle sprain has revealed several characteristic features of CAI. These include diminished range of motion, decreased strength, impaired neuromuscular control, and altered functional movement patterns. We propose a new treatment paradigm for conservative management of CAI with the aim of assessing and treating specific deficits exhibited by individual patients with CAI.

The effect of prefabricated ankle orthoses on balance in athletes with chronic ankle instability in fatigue condition

Introduction: Lateral ankle sprain accounts for 10-28% of all sport injuries. Most of the people with lateral ankle sprain never fully recover and almost 80% of basketball players suffer from repeated ankle injuries. Balance will be distributed in most cases. In addition, athletes can become fatigued physically during competition; this can lead to recurrent ankle sprain when (s) he suffers from previous sprain as one of the orthosis functions is injury prevention, the aim of present study was to examine the effect of prefabricated ankle orthoses on balance in athletes with chronic ankle instability in fatigue condition. Materials and Methods: Twenty basketball players with chronic ankle instability (CAI) and fifteen non-injured athletes participated in this study. Balance was measured for all subjects in normal and fatigue conditions using Biodex Balance System. The three testing conditions included a soft ankle support, spiral spring ankle support, and no orthosis. Analysis of variance (ANOVA) was used to analyze the data and the significance level was set at P < 0.05. Results: this study investigated that the pre-fabricated orthoses could improve balance in healthy athletes and athletes with CAI, in fatigue condition (P < 0.05). Conclusion: As the prefabricated orthoses has a positive influence on balance ability in experienced athletes these assistive devices can be used to prevent further sport injuries. Keywords: Prefabricated orthosis, Fatigue, Ankle instability, Balance

Recent developments on models and inclusion criteria for chronic ankle instability

In the most recent report of injury data on 15 sports from the U.S. National Collegiate Athletic Association (NCAA) Injury Surveillance System over a span of 16 years (1988e2004), ankle ligament sprains were the most common injury. Residual symptoms such as recurrent sprains, pain, instability, and giving way are common after an initial, acute ligament sprain. Chronic ankle instability (CAI) is one of these common problems, and has enjoyed increased interest in the recent literature. However, CAI remains a poorly-defined and understood condition. CAI has been commonly associated with two types of instability, namely mechanical and functional instability. Hertel in 2002 proposed a CAI model that has been very popular (Fig. 1). In this model, CAI is attributed to both mechanical instability and functional instability. Functional instability may be caused by deficits in proprioception, neuromuscular control, postural control, and/or muscular strength. Mechanical instability may be caused by altered mechanics in one or more joints within the ankle complex. Rather than treating these two types of instability independently, this model considers that they are both part of an instability continuum. When both types of instability are present, recurrent ankle sprain occurs. In a recent paper, Hiller et al. proposed a new and updated CAI model that was evolved from Hertel’s original model. In this new model, CAI has a total of seven sub-groups (Fig. 2). In the new model, the triad consists of mechanical instability, perceived instability (instead of functional instability in