Risk factors for lateral ankle sprain: a prospective study among military recruits

Gait kinematics and kinetics in patients with chronic ankle instability and healthy controls: A statistical parametric mapping analysis

BACKGROUND

Chronic ankle instability (CAI) is associated with changes in gait biomechanics which may be related to chronic dysfunction. Traditional statistical models may be limited in their ability to assess the complex 3D movement of the lower extremity during gait. Multivariate analysis of the lower extremity kinematics may reveal unique biomechanical differences associated with CAI.

RESEARCH QUESTION

Do patients with CAI differ from healthy controls in their lower extremity biomechanics and GRF when comparing 3D biomechanics?

METHODS

Thirty-nine young, active adults participated in this study. Data was collected using a 3D motion analysis system while patients walked and jogged. Statistical parametric mapping (SPM) was used to explore 3D GRF, kinematics and kinetics of the of the lower extremity of CAI and healthy patients.

RESULTS

During walking, patients with CAI had greater inversion from 68-100% of gait cycle (p < 0.001, mean difference=3.2°). During jogging, patients with CAI had greater inversion from 20-92% (p < 0.001, mean difference=4.6°). Greater plantar flexion moments were found from 65-71% (p = 0.05, mean difference=347.4Nm/kg) and greater eversion moments were found from 95-100% (p = 0.03, mean difference=74.6Nm/kg) in the CAI group. No differences in GRF were found.

SIGNIFICANCE

Greater inversion may present a potentially injurious position. A faulty position of the rearfoot may require greater muscle function in order to correct the position of the joint resulting in greater eversion moments at the ankle. However, this kinetic change does not appear to correct the ankle position.

Risk factors for acute ankle sprains in field-based, team contact sports: a systematic review of prospective etiological studies

OBJECTIVE

The aim of this systematic review was to identify prospectively measured ankle sprain risk factors in field-based team contact sports.

METHODS

Eight databases including SPORTDiscus, CINAHL Complete, MEDLINE (EBSCO), Education Source, Web of Science, Scopus, Embase, and Pubmed were searched using specific Boolean terms. A modified-CASP diagnostic test assessed the quality of the included studies. Extensive data extraction included but was not limited to injury definition, protocols for injury diagnosis and recording, and outcomes associated with ankle sprain.

RESULTS

4012 records were returned from the online search and 17 studies met the inclusion criteria for this review. Twelve different risk factors including anatomic alignment of the foot and ankle, joint laxity, height, mass, BMI (body mass index), age, ankle strength, hip strength, single leg landing performance (ground reaction force, pelvic internal rotation, and knee varus), and single leg reach were all found to be associated with ankle sprain incidence. Injury definitions and methods of diagnosis and recording varied across the 17 studies.

CONCLUSION

This review updates the literature on prospective risk factors for ankle sprain in a specific population rather than heterogeneous cohorts previously studied. From more than 20 categories of risk factors investigated for ankle sprain association across 17 studies in field-based team contact sports, 12 variables were found to be associated with increased incidence of ankle sprain. In order to reduce the risk of ankle sprain, BMI, ankle plantar and dorsiflexion strength, hip strength, and single leg landing performance should be factored in to athlete assessment and subsequent program design. More studies utilizing standardized definitions and methods of recording and reporting are needed. Future prospective etiological studies will allow strength and conditioning coaches, physiotherapists, and physicians to apply specific training principles to reduce the risk and occurrence of ankle sprain injuries.

Association of clinically-measured and dynamic ankle dorsiflexion assessed by markerless motion capture during the drop-jump task on landing biomechanics and risk of ankle injury in military personnel undergoing 10 weeks of physical training

OBJECTIVES

Determine the influence of clinically-measured maximum dorsiflexion, dynamic peak dorsiflexion and percent of clinically-measured maximum dorsiflexion used during a drop-jump task on landing biomechanics and risk of ankle injury in military personnel.

DESIGN

Prospective cohort study.

METHODS

672 participants (122 women) enrolled. The weightbearing lunge test assessed clinically-measured maximum dorsiflexion averaged across limbs (degrees). Markerless motion capture and force plates collected lower extremity kinematic and kinetic data during a drop-jump task. Percent of clinically-measured maximum dorsiflexion used during landing was calculated as dynamic peak dorsiflexion divided by clinically-measured value, multiplied by 100 (%). De-identified injury data was derived from military physical therapists. Simple linear regression analysis determined the association between dorsiflexion measures and landing biomechanics. Simple binary logistic regression analyses identified predictors of ankle injuries. Statistical significance was set at α = 0.05.

RESULTS

Eighteen participants sustained a traumatic ankle injury from a landing. All measures of dorsiflexion were associated with movement patterns that countered the stiff-legged landing strategy with dynamic measures showing a higher predictive value. Protective factors against ankle injury included height (odds ratio: 0.818, p = 0.006) and weight (odds ratio: 0.824, p = 0.023) for women. Relative braking impulse was a risk factor for men (odds ratio: 1.890, p = 0.001).

CONCLUSIONS

Greater clinically-measured and dynamic measures of dorsiflexion were associated with movement patterns that countered the stiff-legged landing strategy but neither measure of dorsiflexion predicted ankle injury risk. Resultant biomechanics and anthropometrics influenced ankle injury risk to warrant recognition for injury prevention initiatives.

The Burden of the "Simple Ankle Sprains": A Review of the Epidemiology and Long-Term Impact

Lateral ankle sprain (LAS) is not as simple as it was believed to be as it has substantial negative impacts on the active sporting population. The negative impact on physical function, quality of life (QoL) and economic burden is significant with increased risk of reinjury, development of chronic lateral ankle instability and posttraumatic ankle osteoarthritis resulting in functional deficits, decreased QoL and chronic disabilities. Economic burden from a societal perspective demonstrated notably higher indirect costs from productivity loss. Preventative interventions with early surgery for a selective cohort of active sporting population may be considered to mitigate morbidities associated with LAS.

Effect of Different Protection on Lateral Ankle during Landing: An Instantaneous Impact Analysis

Ankle sprain is the most common injury during parachute landing. The biomechanical behavior of the tissues can help us understand the injury mechanism of ankle inversion. To accurately describe the injury mechanism of tissues and assess the effect of ankle protection, a stable time of landing was obtained through the dynamic stability test. It was used for the boundary condition of the foot finite element (FE). The FE model was provided a static load equal to half of the bodyweight applied at the distal tibia and fibula; a foot-boot-brace FE model was established to simulate the landing of subjects on an inversion inclined platform of 0-20°, including non-, external, and elastic ankle braces. Compared with the non-ankle brace, both the external and elastic ankle braces decreased the peak strains of the cal-fibular, anterior Ta-fibular, and posterior Ta-fibular ligaments (15.2-33.0%), and of the peak stress of the fibula (15.2-24.5%). For the strain decrement of the aforementioned ligaments, the elastic brace performed better than the external ankle brace under the inversion of the 10° condition. The peak stress of the fibula (15.6 MPa) decreased up to 24.5% with an elastic brace and 5.6-10.3% with an external brace. The findings suggested that the behaviors of lateral ankle ligaments and fibula were meaningful for the functional ability of the ankle. This provides some suggestions regarding the optimal design of ankle protection.

Epidemiology of Ankle Sprain in the Active-Duty Military Population

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Ankle sprain is one of the most prevalent injuries within the military population, resulting in health-care costs, time away from active duty, and negative impacts on overall readiness.

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Female service members appear to be more likely to sustain ankle sprains than male service members.

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There is a need for additional research on prevention methods and rehabilitation programs for ankle sprains in the military population because the rate of ankle sprain in this population exceeds that in populations with less physically demanding lifestyles. Consequently, low-cost prevention strategies could yield substantial benefits.

Uneven treadmill training for rehabilitation of lateral ankle sprains and chronic ankle instability: a pragmatic randomized controlled trial (Preprint)

Background

Lateral ankle sprains (LASs) are common injuries among military service members. Approximately 40% of individuals with an LAS progress to develop chronic ankle instability (CAI), a condition that results in substantial mechanical and neurophysiological impairment and activity limitation. Since proprioceptive and balance training improve functional outcomes and prevent secondary injury following LAS, they are recommended in clinical practice. Uneven treadmills are an innovative modality that challenge the sensorimotor system while performing an ecologically valid task simulating environments frequently encountered by service members with LAS and CAI.

Objective

The aim of this study is to evaluate whether the inclusion of uneven treadmill training in standard rehabilitation can improve clinical, functional, biomechanical, and patient-reported outcomes compared with the standard of care alone in service members with LAS and CAI. The prophylactic effects of treatment on secondary injury and identification of any contributing or mediating factors that influence outcomes following treatment will also be evaluated. We hypothesize that service members receiving uneven treadmill training will demonstrate greater improvements in clinical and instrumented measures of impairment, patient-reported function, and lower risk of injury recurrence than the control group immediately post and 18 months following treatment.

Methods

A multisite, parallel randomized clinical trial will be performed among service members aged 18-49 years being treated for LAS and CAI in military treatment facilities in the United States. Participants randomly assigned and allocated to receive the experimental intervention will be provided up to 12 sessions of training on an uneven terrain treadmill over a 6-week treatment course to supplement standard rehabilitation care. Treatment intensity of the rehabilitation exercises and treadmill training will be progressed on the basis of patient-perceived intensity and treatment responses. Outcome measures will include patient-reported outcomes, functional assessments, performance measures, and biomechanical measures. Investigators collecting outcome measures will be blinded to treatment allocation. Reinjury rates and patient-reported outcomes of function will be tracked over 18 months following treatment.

Results

The project was funded in September 2020. Patient recruitment began in November 2021, with 3 participants enrolled as of February 2022. Dissemination of the main study findings is anticipated in 2024.

Conclusions

This study will assess the impact of an innovative uneven-terrain treadmill on treatment outcomes in the rehabilitation of service members with LAS and CAI. The results of this study will be used to inform rehabilitation practices and to potentially improve functional outcomes and secondary prevention in this patient population.

Trial Registration

ClinicalTrials.gov NCT04999904; https://clinicaltrials.gov/ct2/show/NCT04999904?term=NCT04999904

International Registered Report Identifier (IRRID)

DERR1-10.2196/38442

Risk Factors Influencing the Incidence of Ankle Sprain Among Elite Football and Basketball Players: A Prospective Study

Introduction. The objective of the present study was to investigate whether certain intrinsic factors (foot hyperpronation, generalized joint laxity) and clinical tests (anterior drawer and talar tilt tests, single-leg balance test and star excursion balance test, ankle and first metatarsophalangeal range of motion) could predict the incidence of lateral ankle sprains among elite football and basketball players during a full year. Method. In a prospective cohort study, 106 elite basketball and football players were recruited. During the preseason period, players underwent baseline measurements. Team physicians in following year reported occurrence of new ankle sprains. Results. Ankle sprain was more frequent among basketball players (P = .01). The history of recurrent (P = .001) and acute ankle sprain (P = .01) and each 5-year increase in age (P = .039) were predictive factors for ankle sprain. No evidence for relationship between other risk factors and occurrence of ankle sprain were achieved. Conclusion. In our study, the history of recurrent and acute ankle sprain was the strongest predictor for ankle injuries. Considering the limitations of this study, it seems mandatory to conduct more prospective studies with a larger sample size and longer follow-up period.Levels of Evidence: Level II: Prognostic.

Syndesmosis Repair Affects in Vivo Distal Interosseous Tibiofibular Ligament Elongation Under Static Loads and During Dynamic Activities

BACKGROUND

Ligamentous ankle injuries are the most common injuries sustained by athletes and by the general population, with an incidence of approximately 2 million per year in the U.S. Injuries to the ankle syndesmosis (i.e., "high ankle sprains") are generally treated operatively. Although cadaveric studies can evaluate syndesmosis fixation strength, they cannot predict how healing, neuromuscular adaptation, or dynamic loading will affect in vivo biomechanics. Using dynamic biplane radiography (DBR), we tested the hypothesis that syndesmosis repair would restore ankle kinematics and ligament elongation during static and dynamic loading.

METHODS

A convenience sample of 6 male patients who had undergone fixation (2 screw, 3 suspensory, 1 hybrid) of syndesmosis injury were assessed with use of DBR during forward running, backpedaling, a 45° angled single-leg hop, and 1 static standing trial at 2 to 4.5 years postoperatively. Three-dimensional ankle kinematics and elongation of the distal interosseous ligament, anterior inferior tibiofibular ligament, and the posterior inferior tibiofibular ligament were measured bilaterally. Comparisons were made between the operative and uninjured sides. Clinical outcomes were evaluated with use of the Foot and Ankle Ability Measure.

RESULTS

Static load increased the lengths of the distal interosseous ligament (p = 0.02 to 0.05) and middle segment of the anterior inferior tibiofibular ligament (p = 0.02) in the operative ankle. The distal syndesmosis length was greater on the operative side during the static unloaded and loaded conditions (p = 0.02). Length of the distal syndesmosis on the operative side was greater than the corresponding healthy syndesmosis length during all 3 dynamic activities. On average, the operative ankle was in less dorsiflexion over the support phase of the angled hop (p = 0.05) and running (p < 0.01). The average Foot and Ankle Ability Measure Activities of Daily Living and Sports subscale scores were 95 and 88, respectively.

CONCLUSIONS

This study provides the first in vivo evidence of post-fixation changes in biomechanics after syndesmosis repair. Syndesmosis repair fails to restore healthy static and dynamic distal tibiofibular anatomy, even in patients who report good to excellent clinical outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Lateral Ankle Sprain and Subsequent Ankle Sprain Risk: A Systematic Review

OBJECTIVE

To evaluate the evidence regarding the association between lateral ankle sprain (LAS) history and the subsequent LAS risk, as well as sex differences in the observed associations.

DATA SOURCES

PubMed, CINAHL, and SPORTDiscus were searched through July 2020 for articles on LAS history and incidence during the study period.

STUDY SELECTION

Studies were included if they were prospective in nature and the authors reported the number of participants with and those without a history of LAS at study initiation as well as the number of participants in each group who sustained an LAS during the investigation.

DATA EXTRACTION

Data were study design parameters as well as the number of participants with and those without an LAS history and the number of subsequent LASs that occurred in both groups. Risk ratios (RRs) with 95% CIs compared the risk of LAS during the study period between those with and those without an LAS history for each investigation.

DATA SYNTHESIS

A total of 19 studies involving 6567 patients were included. The follow-up periods ranged from 14 weeks to 2 years. Assessment scores indicated the studies were of moderate to high quality. A significantly higher risk of LAS during the study period was observed among those with a history of LAS in 10 of 15 studies (RR range = 1.29-6.06). Similar associations were seen in 4 of 6 studies of all-male samples (RR range = 1.38-8.65) and 1 of 4 studies with an all-female sample (RR = 4.28).

CONCLUSIONS

Strong evidence indicates that a previous LAS increased the risk of a subsequent LAS injury. Men with a history of LAS appeared to be at a higher risk of sustaining a subsequent LAS, but women were not. However, further data are needed to draw definitive conclusions from the limited number of sex-specific studies.

Lower Physical Fitness Is Associated with Injuries in Iranian National Futsal Teams: A Prospective Study

Background: Several studies have investigated risk factors for injury in different sports. However, little scientific information is available in relation to futsal injuries. Objectives: This study prospectively analyzed the influence of physical fitness parameters on the occurrence of futsal injuries in Iranian national teams. Methods: Prior to the season, all 55 players of 3 Iranian national futsal teams took part in a series of tests for physical fitness parameters such as cardio-respiratory fitness, muscle strength, body composition, flexibility, agility, and speed. Team physicians recorded all injuries, medical attention, and time loss due to the injury throughout the match and training sessions. Results: During 18 months, 54 futsal injuries were sustained by 32 players. Injured players had poorer performance at baseline in agility, speed, and vertical jump than players who did not incur an injury during the season. Lower maximal oxygen uptake (VO2max) values were associated with a higher injury risk. No differences between injured and uninjured players were observed in age, anthropometric data, flexibility, and lower extremity strength. Conclusions: Some physical fitness parameters were associated with the risk of injuries in futsal. Therefore, improving physical fitness might help to reduce the number of futsal injuries.

Incidence and risk factors for poor ankle functional recovery, and the development and progression of posttraumatic ankle osteoarthritis after significant ankle ligament injury (SALI): the SALI cohort study protocol

Background

Ankle sprains are one of the most common musculoskeletal injuries, accounting for up to 5% of all Emergency Department visits in the United Kingdom. Ankle injury may be associated with future ankle osteoarthritis. Up to 70% of ankle osteoarthritis cases may be associated with previous ankle injury. There is limited research regarding the association between ankle sprain and ankle osteoarthritis development. The current study aims to phenotype those who suffer significant ankle ligament injuries, identify potential risk factors for ankle injuries and subsequent poor recovery, examine why individuals may develop osteoarthritis, and what factors influence this chance.

Methods

In this multicentre cohort study participants were recruited from nine Emergency Departments and two Urgent Care Centres in the United Kingdom. Participants (aged 18–70 years old) were defined as those who had suffered an isolated acute ankle sprain, which was Ottawa Ankle Rules positive, but negative for a significant ankle fracture on x-ray. Age and sex matched controls were also recruited. The controls were individuals who had not suffered a significant ankle injury, including ankle pain, function affected for more than 7 days, or the ankle caused them to report to an Emergency Department. Data is collected through a series of seven questionnaires (at baseline, 3 months, 1 year, 3 years, 5 years, 10 years, and 15 years later). The questionnaires include four sections (demographic questions; index injury, and injury history questions; functional assessment questions; and quality of life questions) and are designed to collect detailed information about the individual, their injury, potential risk factors for ankle sprains and ankle osteoarthritis, plus their medical history and any medication consumed.

Discussion

The Significant Ankle Ligament Injury (SALI) study aims to add to the limited knowledge regarding which factors can predict ankle sprains, complaints, and osteoarthritis. This is important because despite ankle sprains being regarded as a benign injury that resolves quickly, residual symptoms are not uncommon months and years after the injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04230-8.

Anatomical risk factors of lateral ankle sprain in adolescent athletes: A prospective cohort study

OBJECTIVES

The purpose of this study was to identify prospectively the anatomical and functional intrinsic risk factors for lateral ankle sprain (LAS) in adolescent athletes participating in team sports.

DESIGN

A prospective cohort study.

SETTING

University research laboratory.

PARTICIPANTS

A total of 152 adolescent male athletes (age: 14.45 ± 2.96 years; height: 165.63 ± 15.33 cm; weight: 55.60 ± 16.56 kg; body mass index: 19.97 ± 3.58 kg/m²) participated in this study.

MAIN OUTCOME MEASURES

The participants were assessed during the preseason for previous ankle sprain history, navicular drop, tibia vara, Q angle, tibia torsion, knee recurvatum, and ankle ROM. LASs were prospectively recorded and diagnosed for two consecutive seasons (20 months).

RESULTS

Previous ankle sprain history (odds ratio [OR] = 60.911, p < 0.001), increased navicular drop (OR = 1.767, p < 0.001), and knee recurvatum (OR = 1.881, p = 0.002) were positively associated with the incidence of LAS. The receiver operating characteristic (ROC) analyses revealed the predictive potentials of previous ankle sprain history (the area under the ROC [AUROC] = 0.706, p < 0.001), navicular drop (AUROC = 0.906, p < 0.001), and knee recurvatum (AUROC = 0.724, p < 0.001).

CONCLUSION

Athletes with previous ankle sprain history, knee recurvatum, and especially navicular drop may have a greater risk of LAS injury. The data from this study can help therapists and trainers to identify people with a higher risk of LAS.

Screening for laterally deviated plantar pressure during stance using the Cumberland ankle instability tool and anthropometric measures

This study developed a method that predicts laterally deviated plantar pressure during stance by lower limb anthropometrics and self-reported ability to stop an ankle which has started to roll over. Thirty-two males ran on a treadmill for 2 minutes at 11 km/h. Foot pressure data were collected by a pressure insole system for classifying the participants as medial or lateral strikers. Cumberland Ankle Instability Tool score, Tegner Activity Scale score, foot arch height, active and passive ankle and knee range of motion, bi-malleolar width, foot length, foot width and calf circumference were measured. Binary logistic regressions were performed to produce a model which estimated if an individual showed laterally deviated foot pressure during stance. The model utilized the score of Cumberland Ankle Instability Tool Question 8, active and passive knee joint external rotation, height, body mass and bimalleolar width (explained variance of 47.3%, p = 0.037), producing a sensitivity of 71.4% and a specificity of 54.5%. A validation trial on another 15 runners reported a 73.3% accuracy in prediction if they are medial or lateral strikes.

Worldwide epidemiology of foot and ankle injuries during military training: a systematic review

INTRODUCTION

Musculoskeletal foot and ankle injuries are commonly experienced by soldiers during military training. We performed a systematic review to assess epidemiological patterns of foot and ankle injuries occurring during military training.

METHODS

A review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search, done on 14 February 2019, resulted in 1603 reports on PubMed, 565 on Embase and 3 on the Cochrane Library. After reading the remaining full-text articles, we included 91 studies.

RESULTS

Among a population of 8 092 281 soldiers from 15 countries, 788 469 (9.74%) foot and ankle injuries were recorded. Among the 49 studies that reported on length of training, there were 36 770/295 040 (18.17%) injuries recorded among women and 248 660/1 501 672 (16.56%) injuries recorded among men over a pooled mean (±SD) training period of 4.51±2.34 months. Ankle injuries were roughly 7 times more common than foot injuries, and acute injuries were roughly 24 times more common than non-acute injuries. Our findings indicated that, during a 3-month training period, soldiers have a 3.14% chance of sustaining a foot and ankle injury. The incidence of foot or ankle injury during military parachutist training was 3.1 injuries per thousand jumps.

CONCLUSIONS

Our findings provide an overview of epidemiological patterns of foot and ankle injuries during military training. These data can be used to compare incidence rates of foot and ankle injuries due to acute or non-acute mechanisms during training. Cost-effective methods of preventing acute ankle injuries and non-acute foot injuries are needed to address this problem.

Center of Pressure, Vertical Ground Reaction Forces, and Neuromuscular Responses of Special-Forces Soldiers to 43-km Load Carriage in the Field

The primary purpose of this study was to examine lateral deviations in center of pressure as a result of an extreme-duration load carriage task, with particular focus on heel contact. A total of 20 (n = 17 males and n = 3 females) soldiers from a special operation forces unit (body mass 80.72 [21.49] kg, stature 178.25 [8.75] cm, age 26 [9] y) underwent gait plantar pressure assessment and vertical jump testing before and after a 43-km load carriage event (duration 817.02 [32.66] min) carrying a total external load of 29.80 (1.05) kg. Vertical jump height decreased by 18.62% (16.85%) from 0.30 (0.08) to 0.24 (0.07) m, P < .001. Loading peak and midstance force minimum were significantly increased after load carriage (2.59 [0.51] vs 2.81 [0.61] body weight, P = .035, Glass delta = 0.44 and 1.28 [0.40] vs 1.46 [0.41] body weight, P = .015, Glass delta = 0.45, respectively) and increases in lateral center of pressure displacement were observed as a result of the load carriage task 14.64 (3.62) to 16.97 (3.94) mm, P < .029. In conclusion, load carriage instigated a decrease in neuromuscular function alongside increases in ground reaction forces associated with injury risk and center of pressure changes associated with ankle sprain risk. Practitioners should consider that possible reductions in ankle stability remain once load carriage has been completed, suggesting soldiers are still at increased risk of injury even once the load has been removed.

Can musculoskeletal screening test findings guide interventions for injury prevention and return from injury in field hockey?

OBJECTIVES

The aim of this study is to identify if intrinsic factors tested in the preseason screening (PSS) can identify an elevated risk of injury. This aim has two aspects; to assess whether previous injury is associated with ongoing deficits in performance, and to assess if the PSS can identify differences in intrinsic factors that profile risk of future injury.

DESIGN

A cohort of state level field hockey players were tested on a screening test battery including proprioception, postural stability, muscular strength and range of motion, to establish if these intrinsic factors were useful in identifying elevated risk of injury. Retrospective injury data was collated to determine association with previous injury and prospective injury data was collated to determine association with future injury.

PARTICIPANTS

A total of 130 field hockey players were included in this study, from state level squads (age ± SD = 20.96 (3.75); height = 176.09 cm). Groups for prescreening and post screening injury status (injured/not injured) were established for comparison to screening test results.

RESULTS

Right Active Movement Extent Discrimination Assessment (AMEDA), left AMEDA and right Y-balance test (YBT) anterior direction (Ant) were significantly associated (p < 0.05) with injury prior to screening. Right YBTAnt and right and left hip internal rotation (IR) were significantly associated (p < 0.05) with injury post screening. The YBTAnt and YBT posteromedial (PMed) reach directions and Hip IR are associated with previous hamstring injury and show a difference between post screening injured and non-injured groups.

CONCLUSIONS

AMEDA, R YBTAnt, Hip IR tests should be a focus for recovery after previous injury and during season preparation. Full recovery may improve readiness to return to play and reduce risk of primary injury or re-injury. YBTAnt and YBTPmed and Hip IR show a performance deficit link between previous injury and subsequent re-injury of hamstrings. Since these are the most common re-injury types in this cohort, these tests are clinically useful in informing return to play decisions for hockey players.

Hamstring Autograft for Lateral Ligament Stabilization

PURPOSE OF REVIEW

This paper seeks to review the current literature and trends regarding use of hamstring autograft for lateral ankle instability.

RECENT FINDINGS

Reconstruction of the lateral ankle ligaments using hamstring autograft has been found to be an effective method to treat ankle instability in terms of patient-reported outcomes and objective measures. Biomechanically, reconstruction has been shown to be stronger (load to failure) when compared with the Broström procedure. Clinical studies have demonstrated non-inferiority when compared with the Broström procedure, with one synthetic reconstruction technique demonstrating superior outcomes. Reconstruction of the lateral ankle ligaments using hamstring autograft is especially useful in patients who are at high risk of failure (insufficient soft tissue available for repair, ligamentous laxity, previous failed ligament repair, ossicle > 1 cm, or in the heavier, high-demand athletes).

Chronic ankle instability patients exhibit higher variability in lower extremity joint-coupling variability during drop vertical jumps

Chronic ankle instability (CAI) has been associated with biomechanical alterations during landing tasks. While joint coupling differences have been reported during gait in patients with CAI, there is no known research assessing joint coupling during a drop-vertical jumping (DVJ). Joint coupling variability measure may provide information on the sensorimotor health of these patients. The purpose of this study was to compare lower extremity joint coupling variability during a DVJ between patients with CAI and controls. Twenty-eight young, active individuals (CAI:n = 14, Control:n = 14) participated in the study. A 3D motion capture system was used to collect kinematics during 15 drop-vertical jump trials. A vector coding analysis was used to assess the variability in the following joint couples: knee sagittal-ankle frontal, knee sagittal-ankle sagittal, hip frontal-ankle frontal, and hip frontal-ankle sagittal. The CAI group had higher joint coupling variability in hip frontal-ankle sagittal, knee sagittal-ankle frontal and knee sagittal-ankle sagittal planes both prior to and following ground contact during the drop vertical jumps. These changes indicate potential adaptations to the constraint of CAI and the task of the DVJ. Higher variability may reflect an attempt by the subjects to explore alternate movement strategies or reflect poor sensorimotor control strategies. Clinicians should consider the challenges of DVJ during rehabilitation as they create a unique task constraint.

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.

ANKLE SPRAIN RISK FACTORS: A 5-MONTH FOLLOW-UP STUDY IN VOLLEY AND BASKETBALL ATHLETES

ABSTRACT Introduction Ankle sprain is a frequent sports injury among volley and basketball players, and identifying risk factors is necessary to prevent injuries and prolong their careers. Objective To identify intrinsic and extrinsic factors in basketball and volleyball players related to the risk of ankle sprain injury over a five-month follow-up period. Methods Ninety-four Brazilian young competitive athletes (15.8±1.7 years, 47 basketball and 47 volleyball players) participated in this study. They were evaluated for intrinsic risk factors (previous history of ankle sprain, dominant lower limb, ankle ligament laxity, range of motion of the ankle-foot complex, electromyographic response time of ankle evertors, postural control and muscular torque of ankle invertors and evertors) and extrinsic risk factors (type of shoes worn, use of orthosis, previous injuries while training or competing, and the players’ position). Results During the study period, 18 (19%) athletes suffered unilateral sprains. Multivariate logistic regression analysis gave a final regression with four factors: dominant leg (p=0.161), type of shoes worn (p=0.049), player’s position (p=0.153), and peroneus brevis muscle reaction time (p=0.045). There was an 86.1% probability of an ankle sprain if the athlete had a left dominant leg, wore shoes without vibration dampeners, or played in the small forward, wing/hitter spiker, middle blocker, or opposite spiker positions, and had a peroneus muscle reaction time longer than 80ms. However, only the player’s position was significantly (p=0.046) associated with lesion occurrence. Conclusion The player’s position appeared to be a risk factor in both sports, and this result may help professionals to prevent ankle sprains. Level of Evidence I; High quality randomized clinical trial with or without statistically significant difference but with narrow confidence intervals.

Bilateral Strength Asymmetries and Unilateral Strength Imbalance: Predicting Ankle Injury When Considered With Higher Body Mass in US Special Forcesa

CONTEXT

Ankle injury is one of the most common conditions in athletics and military activities. Strength asymmetry (SA) and imbalance may represent a risk factor for injury, but past investigations have produced ambiguous conclusions. Perhaps one explanation for this ambiguity is the fact that these authors used univariate models to predict injury.

OBJECTIVE

To evaluate the predictive utility of SA and imbalance calculations for ankle injury in univariate and multivariate prediction models.

DESIGN

Prospective cohort study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 140 male US Air Force Special Forces.

MAIN OUTCOME MEASURE(S)

Baseline testing consisted of body composition, isometric strength, and aerobic and anaerobic capacity. A clinician conducted medical chart reviews 365 days posttesting to document the incidence of ankle injury. Strength asymmetries were calculated based on the equations most prevalent in the literature along with known physiological predictors of injury in the military: age, height, weight, body composition, and aerobic capacity. Simple logistic regression was conducted using each predictor, and backward stepwise logistic regression was conducted with each equation method and the physiological predictors entered initially into the model.

RESULTS

Strength asymmetry or imbalance or both, as a univariate predictor, was not able to predict ankle injury 365 days posttesting. Body mass (P = .01) and body mass index (P = .01) significantly predicted ankle injury. Strength asymmetry or imbalance or both significantly predicted ankle injury when considered with body mass (P = .002-.008).

CONCLUSIONS

As a univariate predictor, SA did not predict ankle injury. However, SA contributed significantly to predicting ankle injury in a multivariate model using body mass. Interpreting SA and imbalance in the presence of other physiological variables can help elucidate the risk of ankle injury.

The Role of the Accessory Malleolar Ossicles and Malleolar Avulsion Fractures in Lateral Ankle Ligament Reconstruction

While it is well known that ankle sprains are one of the most common injuries in the United States, predictive factors regarding failure of conservative treatment are not well known. There are many biomechanical and epidemiological factors that play a role in recurrence and failure of conservative treatment, but most cases are able to be treated with immobilization and/or rest, ice, elevation, physical therapy, and bracing. We propose that one important risk factor is often overlooked simply due to the fact that a vast majority of these cases resolve without the need for surgery. Accessory ossicles and avulsion fractures of the malleoli or talus may represent a predisposition or marker for ligamentous damage that may lead to the need for lateral ankle ligament repair or reconstruction in the future. We have identified 61 consecutive patients who underwent lateral ankle ligament repair or reconstruction by the primary surgeon from the years 2007 to 2017. Out of those patients who met our inclusion and exclusion criteria, 66% had the presence of osseous pathology consisting of accessory ossicles or avulsion fractures of the medial or lateral malleolus or talus. The proportion of osseous pathology seen with lateral ankle ligament repair or reconstruction was higher than what has been previously reported in both operative and nonoperative settings. This may help identify a risk factor for failure of conservative treatment in patients presenting with acute ankle sprains or ankle instability especially in the active cohort.

LEVELS OF EVIDENCE

Level IV: Case series.

A risk assessment model for chronic ankle instability: indications for early surgical treatment? An observational prospective cohort - study protocol

BACKGROUND

Chronic ankle instability (CAI) is a common result of an ankle sprain. Even though early surgical treatment yields the best results, overall only professional athletes are eligible for acute surgical stabilization. Treating all patients with early surgical stabilization leads to a high amount of unnecessary invasive interventions, as not all patients progress to CAI. If patients at risk of developing CAI can be identified, treatment policies may be applied more effectively and efficiently. The purpose of this study is to develop a risk assessment model to identify patients at risk for CAI that should receive early surgical treatment.

METHODS

In this observational prospective cohort, all patients aged sixteen years and older, reporting at the emergency department of one of the participating hospitals after sustaining a lateral ankle sprain, and filled out 1 out of 3 follow-up questionnaires and the 1 year follow-up are included. A lateral and anteroposterior radiograph is made. Patients are excluded if a fracture or other pathology is present. The included patients receive four questionnaires, including questions focusing on the sprain, treatment and complaints, the Foot and Ankle Outcome Score and the Cumberland Ankle Instability Tool. A total of eleven radiographic variables are assessed for inter- and intra-observer reliability. Additionally, four factors extracted from the questionnaires, will be evaluated for correlation with CAI. Significantly correlating factors (e.a. risk factors) will be implemented in a risk assessment model. For the final model, based on sixteen variables with a minimum of 20 events per variable and a prevalence of 30-40% after an initial sprain, a sample size of 2370 patients is needed to perform both internal and external model validation.

DISCUSSION

This study will develop the first large scale model for the risk at CAI after an ankle sprain combining radiographic and patient characteristics. With this risk assessment model, patients at risk for CAI may be identified and properly informed on the treatment options. Patients identified as being at risk, may receive more adequate follow-up and become eligible for early surgical stabilization. This prevents patients from experiencing unnecessary long-lasting complaints, increasing the success rate of conservative and surgical treatment.

TRIAL REGISTRATION

Retrospectively registered: NCT02955485 [Registration date: 3-11-2016]. NTR6139 [Registration date: 3-1-2017].

Effects of Hip Strengthening on Neuromuscular Control, Hip Strength, and Self-Reported Functional Deficits in Individuals With Chronic Ankle Instability

CONTEXT

Deficits in ankle and hip strength and lower-extremity postural control are associated with chronic ankle instability (CAI). Following strength training, muscle groups demonstrate increased strength. This change is partially credited to improved neuromuscular control, and many studies have investigated ankle protocols for subjects with CAI. The effects of isolating hip musculature in strength training protocols in this population are not well understood.

OBJECTIVE

To examine the effects of hip strengthening on clinical and self-reported outcomes in patients with CAI.

DESIGN

Prospective randomized controlled clinical trial.

SETTING

Athletic training facility.

PARTICIPANTS

Twenty-six participants with CAI (12 males and 14 females; age = 20.9 [1.5] y, height = 170.0 [12.7] cm, and mass = 77.5 [17.5] kg) were randomly assigned to training or control groups.

INTERVENTION

Participants completed either 4 weeks of supervised hip strengthening (resistance bands 3 times a week) or no intervention.

MAIN OUTCOME MEASURES

Participants were assessed on 4 clinical measures (Star Excursion Balance Test in the anterior, posteromedial, and posterolateral directions; Balance Error Scoring System; hip external rotation strength; and hip abduction strength) and a patient-reported measure (the Foot and Ankle Ability Measure activities of daily living and sports subscales) before and after the 4-week training period.

RESULTS

The training group displayed significantly improved posttest measures compared with the control group for hip abduction strength (training: 446.3 [77.4] N, control: 314.7 [49.6] N, P < .01); hip external rotation strength (training: 222.1 [48.7] N, control: 169.4 [34.6] N, P < .01); Star Excursion Balance Test reach in the anterior (training: 93.1% [7.4%], control: 90.2% [7.9%], P < .01), posteromedial (training: 96.3% [8.9%], control: 88.0% [8.8%], P < .01), and posterolateral (training: 95.4% [11.1%], control: 86.6% [9.6%], P < .01) directions; Balance Error Scoring System total errors (training: 9.9 [6.3] errors, control: 21.2 [6.3] errors, P < .01); and the Foot and Ankle Ability Measure-sports score (training: 88.0 [12.6], control: 84.8 [10.9], P < .01).

CONCLUSION

Improved clinical and patient-reported outcomes in the training group suggest hip strengthening is beneficial in the management and prevention of recurrent symptoms associated with CAI.

The regenerative therapies of the ankle degeneration: a focus on multipotential mesenchymal stromal cells

The ankle degeneration ranging from focal osteochondral lesions to osteoarthritis can cause a total joint function loss. With rising life expectancy and activity of the patients, various regenerative therapies were introduced aiming to preserve the joint function via the induction of cartilage and bone repair. Here, biological events and mechanical changes of the ankle degeneration were discussed. The regenerative therapies were reviewed versus the standard surgical treatment. We especially focused on the use of mesenchymal (multipotential) stromal cells (MSCs) highlighting their dual functions of regeneration and cell modulation with an emphasis on the emerging MSC-based clinical studies. Being at an early step, more basic and clinical research is needed to optimize the applications of all ankle regenerative therapies including MSC-based methods.

The immediate effect of talocrural joint manipulation on functional performance of 15-40 years old athletes with chronic ankle instability: A double-blind randomized clinical trial

OBJECTIVE

To evaluate the immediate effect of talocrural joint manipulation (TCJM) on functional performance of athletes with chronic ankle instability (CAI).

PARTICIPANTS

Forty athletes (18males, 22females) with CAI divided into TCJM group (n = 20) and sham manipulation group (n = 20).

INTERVENTION

TCJM was performed as a quick thrust on the involved talus, in the posterior direction. Sham manipulation was maintaining the same position, without any thrust.

MAIN OUTCOME MEASURES

Functional performance of athletes was assessed with single leg hop; speed and Y balance tests, before and after the interventions.

RESULTS

All functional tests evaluated in this study improved significantly after TCJM (p-value<0.05). These findings were not seen in the control group. Between-group comparisons also showed significant changes for all the measurements after the interventions (p < 0.05).

CONCLUSIONS

TCJM can significantly increase the functional performance of athletes with CIA and can be an effective supplementary treatment for these subjects. However, this was a pre-post study and future studies with long-term follow-ups may provide more reliable results about the long-term effectiveness of this type of treatment.

Preventing recurrent ankle sprains: Is the use of an App more cost-effective than a printed Booklet? Results of a RCT

Recurrent ankle sprains can be reduced by following a neuromuscular training (NMT) program via a printed Booklet or a mobile application. Regarding the high incidence of ankle sprains, cost-effectiveness regarding implementation can have a large effect on total societal costs. In this economic analysis, we evaluated whether the method of implementing a proven effective NMT program using an App or a Booklet resulted in differences in injury incidence rates leading to costs and hence to differences in cost-effectiveness. In total, 220 athletes with a previous ankle sprain were recruited for this randomized controlled trial with a follow-up of 12 months. Half of the athletes used the freely available "Strengthen your ankle" App and the other half received a printed Booklet. After the 8-week program, athletes were questioned monthly on their recurrent injuries. Primary outcome measures were incidence density of ankle injury and incremental cost-effectiveness ratio (ICER). During follow-up, 31 athletes suffered from a recurrent ankle sprain that led to costs resulting in a hazard ratio of 1.13 (95% CI: 0.56-2.27). The incremental cost-effectiveness ratio of the App group in comparison with the Booklet group was €361.52. The CE plane shows that there was neither a difference in effects nor in costs between both intervention methods. This study showed that the method of implementing the NMT program using an App or a Booklet led to similar cost-effectiveness ratios and the same occurrence of recurrent injuries leading to costs. Both the App and the Booklet can be used to prevent recurrent ankle injuries, showing no differences in (cost-) effectiveness at 12-month follow-up.

Operative treatment of lateral ligament instability

PURPOSE OF REVIEW

Ankle sprains, which account for 40% of sports injuries in the USA, can lead to chronic ankle instability. Chronic ankle instability can be classified as functional, mechanical, or a combination of both and is diagnosed using a combination of a physical exam, an MRI, and stress radiographs. This review focuses on different approaches to treatment, including non-operative and operative techniques, of chronic ankle instability, including reviewing traditional procedures as well as more novel and newer techniques.

RECENT FINDINGS

Based on existing literature, non-operative treatment should always precede operative treatment of chronic ankle instability. If rehabilitation fails, Brostrom-Gould type ankle stabilization has been the preferred surgical option. Recent literature suggests that arthroscopic repair might reduce recovery time and improve outcomes in certain populations; however, there are higher rates of complication following these surgeries. In more high-risk populations, some literature reports that ligament repair with peroneus brevis transfer could be a more effective treatment option. Currently, varying surgical techniques exist for the treatment of chronic ankle instability. While the more recently reported techniques show promise, it is important to note that there is little evidence showing they are more successful than traditional techniques. It is imperative that future studies focus on outcomes and complication rates of these newer procedures.

The Athletic Shoe in Football

BACKGROUND

Foot and ankle injuries are common in sports, particularly in cleated athletes. Traditionally, the athletic shoe has not been regarded as a piece of protective equipment but rather as a part of the uniform, with a primary focus on performance and subjective feedback measures of comfort. Changes in turf and shoe design have poorly understood implications on the health and safety of players.

EVIDENCE ACQUISITION

A literature search of the MEDLINE and PubMed databases was conducted. Keywords included athletic shoewear, cleated shoe, football shoes, and shoewear, and search parameters were between the years 2000 and 2016.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

The athletic shoe is an important piece of protective sports equipment. There are several important structural considerations of shoe design, including biomechanical compliance, cleat and turf interaction, and shoe sizing/fit, that affect the way an athlete engages with the playing surface and carry important potential implications regarding player safety if not understood and addressed.

CONCLUSION

Athletic footwear should be considered an integral piece of protective equipment rather than simply an extension of the uniform apparel. More research is needed to define optimal shoe sizing, the effect that design has on mechanical load, and how cleat properties, including pattern and structure, interact with the variety of playing surfaces.

Hip Strength as an Intrinsic Risk Factor for Lateral Ankle Sprains in Youth Soccer Players: A 3-Season Prospective Study

BACKGROUND

Numerous epidemiological studies have emphasized the burden of lateral ankle sprains in youth soccer players. However, no prospective study has identified intrinsic physical and modifiable risk factors for these injuries in this particular population. Although injury prevention programs in soccer incorporate proximal hip and core stability exercises, it is striking that the relationship between impaired proximal hip function and ankle sprains has not yet been prospectively investigated in youth soccer players.

HYPOTHESIS

This prospective study aimed to examine whether hip muscle strength is a risk factor for sustaining a lateral ankle sprain in youth soccer players. We hypothesized that decreased hip muscle strength would predispose youth soccer players to an increased risk of lateral ankle sprains.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This study included a total of 133 male youth soccer players (age divisions U11-U17) for analysis. At the beginning of the season, anthropometric characteristics were collected and hip muscle strength was assessed using a handheld dynamometer. Injury registration was performed by the team medical staff during 3 consecutive seasons. A principal-component, multivariate Cox regression analysis was performed to identify potential risk factors for sustaining a lateral ankle sprain.

RESULTS

Twelve participants (18% of all reported injuries) sustained a lateral ankle sprain (0.36 per 1000 athletic-exposure hours). After adjustment for body size dependencies and other hip muscle forces, an increase in hip muscle extension force was associated with a significant decrease in the hazard of the injury (hazard ratio, 0.3; 95% confidence interval, 0.1-0.9; P = .028). No other study variable could be identified as a risk factor for lateral ankle sprains.

CONCLUSION

Reduced hip extension muscle strength is an independent risk factor for lateral ankle sprains in male youth soccer players. Other hip muscle strength outcomes were not identified as risk factors. Replication in larger samples with more injured cases is warranted to further ascertain the importance of this risk factor.

A narrow bimalleolar width is a risk factor for ankle inversion injury in male military recruits: A prospective study

BACKGROUND

Ankle inversion injuries are one of the most common and burdensome injuries in athletic populations. Research that prospectively identifies characteristics associated with this injury is lacking. This prospective study compared baseline anthropometric and biomechanical gait characteristics of military recruits who sustained an ankle inversion injury during training, with those who remained injury-free.

METHODS

Bilateral plantar pressure and three-dimensional lower limb kinematics were recorded in 1065 male, injury-free military recruits, during barefoot running. Injuries that occurred during the 32-week recruit training programme were subsequently recorded. Data were compared between recruits who sustained an ankle inversion injury during training (n=27) and a sample (n=120) of those who completed training injury-free. A logistic regression analysis was used to identify risk factors for this injury.

FINDINGS

A narrower bimalleolar width and an earlier peak pressure under the fifth metatarsal were predictors of ankle inversion injury. Those who sustained an ankle inversion injury also had a lower body mass, body mass index, and a smaller calf girth than those who completed training injury-free.

INTERPRETATION

Anthropometric and dynamic gait characteristics have been identified that may predispose recruits to an ankle inversion injury during Royal Marine recruit training, allowing identification of recruits at higher risk at the start of training.

Intrinsic Risk Factors of Lateral Ankle Sprain: A Systematic Review and Meta-analysis

Context:

Lateral ankle ligamentous sprain (LAS) is one of the most common injuries in recreational activities and competitive sports. Many studies have attempted to determine whether there are certain intrinsic factors that can predict LAS. However, no consensus has been reached on the predictive intrinsic factors.

Objective:

To identify the intrinsic risk factors of LAS by meta-analysis from data in randomized control trials and prospective cohort studies.

Data Sources:

A systematic computerized literature search of MEDLINE, CINAHL, ScienceDirect, SPORTDiscus, and Cochrane Register of Clinical Trials was performed.

Study Selection:

A computerized literature search from inception to January 2015 resulted in 1133 studies of the LAS intrinsic risk factors written in English.

Study Design:

Systematic review.

Level of Evidence:

Level 4.

Data Extraction:

The modified quality index was used to assess the quality of the design of the papers and the standardized mean difference was used as an index to pool included study outcomes.

Results:

Eight articles were included in this systematic review. Meta-analysis results showed that body mass index, slow eccentric inversion strength, fast concentric plantar flexion strength, passive inversion joint position sense, and peroneus brevis reaction time correlated with LAS.

Conclusion:

Body mass index, slow eccentric inversion strength, fast concentric plantar flexion strength, passive inversion joint position sense, and the reaction time of the peroneus brevis were associated with significantly increased risk of LAS.

Effect of early supervised physiotherapy on recovery from acute ankle sprain: randomised controlled trial

OBJECTIVE

 To assess the efficacy of a programme of supervised physiotherapy on the recovery of simple grade 1 and 2 ankle sprains.

DESIGN

 A randomised controlled trial of 503 participants followed for six months.

SETTING

 Participants were recruited from two tertiary acute care settings in Kingston, ON, Canada.

PARTICIPANTS

 The broad inclusion criteria were patients aged ≥16 presenting for acute medical assessment and treatment of a simple grade 1 or 2 ankle sprain. Exclusions were patients with multiple injuries, other conditions limiting mobility, and ankle injuries that required immobilisation and those unable to accommodate the time intensive study protocol.

INTERVENTION

 Participants received either usual care, consisting of written instructions regarding protection, rest, cryotherapy, compression, elevation, and graduated weight bearing activities, or usual care enhanced with a supervised programme of physiotherapy.

MAIN OUTCOME MEASURES

 The primary outcome of efficacy was the proportion of participants reporting excellent recovery assessed with the foot and ankle outcome score (FAOS). Excellent recovery was defined as a score ≥450/500 at three months. A difference of at least 15% increase in the absolute proportion of participants with excellent recovery was deemed clinically important. Secondary analyses included the assessment of excellent recovery at one and six months; change from baseline using continuous scores at one, three, and six months; and clinical and biomechanical measures of ankle function, assessed at one, three, and six months.

RESULTS

 The absolute proportion of patients achieving excellent recovery at three months was not significantly different between the physiotherapy (98/229, 43%) and usual care (79/214, 37%) arms (absolute difference 6%, 95% confidence interval -3% to 15%). The observed trend towards benefit with physiotherapy did not increase in the per protocol analysis and was in the opposite direction by six months. These trends remained similar and were never statistically or clinically important when the FAOS was analysed as a continuous change score.

CONCLUSIONS

 In a general population of patients seeking hospital based acute care for simple ankle sprains, there is no evidence to support a clinically important improvement in outcome with the addition of supervised physiotherapy to usual care, as provided in this protocol.Trial registration ISRCTN 74033088 (www.isrctn.com/ISRCTN74033088).

The ability of the Biodex Stability System to distinguish level of function in subjects with a second-degree ankle sprain

Objective: To assess the capacity of the Biodex Stability System using a one-leg stance protocol to differentiate between injured and non-injured limbs and between level of disabilities.

Design: Cross-sectional study.

Setting: Military and civilian clinic.

Subjects: Thirty-four individuals with a second-degree lateral ankle sprain and 36 healthy subjects.

Methods and measures: Subjects were tested on the Stability System 30 days after injury using a one-leg stance protocol in the dynamic limit-of-stability mode. All subjects also filled out a disability questionnaire (Lower Extremity Functional Scale). The groups were compared based on the overall dynamic limit-of-stability score and its relationship with the score on the disability questionnaire was also examined.

Results: The overall dynamic limit-of-stability scores (subjects with a lateral ankle sprain: 13.0% (5.5)-26.0% (9.2); healthy subjects: 16.9% (7.9)-27.9% (9.6)) clustered in the lower end of the theoretical range of 0–100%. Statistically significant differences in the overall dynamic limit-of-stability scores were found between the injured and non-injured limbs but group differences were small and clinically not relevant. No significant relationships were found between the overall dynamic limit-of-stability scores and the Lower Extremity Functional Scale scores (58.2 (11.8)) of the subjects with a lateral ankle sprain.

Conclusions: The one-leg stance protocol carried out in the dynamic limit-of-stability mode is very challenging and offers a very limited capacity to differentiate between injured and non-injured limbs. The main outcome of the Stability System does not appear to be a good indicator of the functional capacity of people with a lateral ankle sprain.

Shoe heel abrasion and its possible biomechanical cause: a transversal study with infantry recruits

BACKGROUND

Excessive shoe heel abrasion is of concern to patients and shoe manufacturers, but little scientific information is available about this feature and its possible causes. The purpose of this study was to relate this phenomenon with biomechanical factors that could predispose to shoe heel abrasion.

METHODS

Ninety-seven recruits (median age 25) were enrolled in this study. Shoe abrasion was assessed manually with a metric plastic tape on the posterior part of the heel that comes in contact with the ground. The number of sprains, foot alignment, and calf muscle shortening (Silfverskiold test) was also assessed in order to relate it with shoe heel abrasion. After using our exclusion criteria, 86 recruits and 172 were considered for this study.

RESULTS

The most common abrasion site was the lateral portion of the heel surface (50 %). Forty-four percent of the participants had neutral hind-foot alignment and 39 % had valgus alignment. Twenty-six (30 %) patients have had previous ankle or foot sprains. Neutral foot was related with less calf muscle shortening. On the other hand, valgus hind-foot alignment was more associated with Achilles shortening (p < 0.05). Patients with neutral alignment were associated with more uniform shoe heel abrasion and varus feet were associated with more central and lateral abrasion (p < 0.05). The pattern of shoe heel abrasion was not statistically related with calf muscle shortening nor with number of sprains.

CONCLUSION

This study was able to correlate shoe heel abrasion with biomechanical causes (neutral alignment-uniform abrasion/varus alignment-central and lateral abrasion). More effort has to be done to continue evaluating outsole abrasion with its possible biomechanical cause in order to predict and treat possible associated injuries.

A Refined Prediction Model for Core and Lower Extremity Sprains and Strains Among Collegiate Football Players

CONTEXT

Researchers have identified high exposure to game conditions, low back dysfunction, and poor endurance of the core musculature as strong predictors for the occurrence of sprains and strains among collegiate football players.

OBJECTIVE

To refine a previously developed injury-prediction model through analysis of 3 consecutive seasons of data.

DESIGN

Cohort study.

SETTING

National Collegiate Athletic Association Division I Football Championship Subdivision football program.

PATIENTS OR OTHER PARTICIPANTS

For 3 consecutive years, all 152 team members (age = 19.7 ± 1.5 years, height = 1.84 ± 0.08 m, mass = 101.08 ± 19.28 kg) presented for a mandatory physical examination on the day before initiation of preseason practice sessions.

MAIN OUTCOME MEASURE(S)

Associations between preseason measurements and the subsequent occurrence of a core or lower extremity sprain or strain were established for 256 player-seasons of data. We used receiver operating characteristic analysis to identify optimal cut points for dichotomous categorizations of cases as high risk or low risk. Both logistic regression and Cox regression analyses were used to identify a multivariable injury-prediction model with optimal discriminatory power.

RESULTS

Exceptionally good discrimination between injured and uninjured cases was found for a 3-factor prediction model that included equal to or greater than 1 game as a starter, Oswestry Disability Index score equal to or greater than 4, and poor wall-sit-hold performance. The existence of at least 2 of the 3 risk factors demonstrated 56% sensitivity, 80% specificity, an odds ratio of 5.28 (90% confidence interval = 3.31, 8.44), and a hazard ratio of 2.97 (90% confidence interval = 2.14, 4.12).

CONCLUSIONS

High exposure to game conditions was the dominant injury risk factor for collegiate football players, but a surprisingly mild degree of low back dysfunction and poor core-muscle endurance appeared to be important modifiable risk factors that should be identified and addressed before participation.

Functional ankle instability as a risk factor for osteoarthritis: using T2-mapping to analyze early cartilage degeneration in the ankle joint of young athletes

OBJECTIVE

The aim of this study was to investigate, using T2-mapping, the impact of functional instability in the ankle joint on the development of early cartilage damage.

METHODS

Ethical approval for this study was provided. Thirty-six volunteers from the university sports program were divided into three groups according to their ankle status: functional ankle instability (FAI, initial ankle sprain with residual instability); ankle sprain Copers (initial sprain, without residual instability); and controls (without a history of ankle injuries). Quantitative T2-mapping magnetic resonance imaging (MRI) was performed at the beginning ('early-unloading') and at the end ('late-unloading') of the MR-examination, with a mean time span of 27 min. Zonal region-of-interest T2-mapping was performed on the talar and tibial cartilage in the deep and superficial layers. The inter-group comparisons of T2-values were analyzed using paired and unpaired t-tests. Statistical analysis of variance was performed.

RESULTS

T2-values showed significant to highly significant differences in 11 of 12 regions throughout the groups. In early-unloading, the FAI-group showed a significant increase in quantitative T2-values in the medial, talar regions (P = 0.008, P = 0.027), whereas the Coper-group showed this enhancement in the central-lateral regions (P = 0.05). Especially the comparison of early-loading to late-unloading values revealed significantly decreasing T2-values over time laterally and significantly increasing T2-values medially in the FAI-group, which were not present in the Coper- or control-group.

CONCLUSION

Functional instability causes unbalanced loading in the ankle joint, resulting in cartilage alterations as assessed by quantitative T2-mapping. This approach can visualize and localize early cartilage abnormalities, possibly enabling specific treatment options to prevent osteoarthritis in young athletes.

The incidence and prevalence of ankle sprain injury: a systematic review and meta-analysis of prospective epidemiological studies

BACKGROUND

Ankle sprain is one of the most common musculoskeletal injuries, yet a contemporary review and meta-analysis of prospective epidemiological studies investigating ankle sprain does not exist.

OBJECTIVE

Our aim is to provide an up-to-date account of the incidence rate and prevalence period of ankle sprain injury unlimited by timeframe or context activity.

METHODS

We conducted a systematic review and meta-analyses of English articles using relevant computerised databases. Search terms included Medical Search Headings for the ankle joint, injury and epidemiology. The following inclusion criteria were used: the study must report epidemiology findings of injuries sustained in an observed sample; the study must report ankle sprain injury with either incidence rate or prevalence period among the surveyed sample, or provide sufficient data from which these figures could be calculated; the study design must be prospective. Independent extraction of articles was performed by two authors using pre-determined data fields.

RESULTS

One-hundred and eighty-one prospective epidemiology studies from 144 separate papers were included. The average rating of all the included studies was 6.67/11, based on an adapted version of the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) guidelines for rating observational studies. 116 studies were considered high quality and 65 were considered low quality. The main findings of the meta-analysis demonstrated a higher incidence of ankle sprain in females compared with males (13.6 vs 6.94 per 1,000 exposures), in children compared with adolescents (2.85 vs 1.94 per 1,000 exposures) and adolescents compared with adults (1.94 vs 0.72 per 1,000 exposures). The sport category with the highest incidence of ankle sprain was indoor/court sports, with a cumulative incidence rate of 7 per 1,000 exposures or 1.37 per 1,000 athlete exposures and 4.9 per 1,000 h. Low-quality studies tended to underestimate the incidence of ankle sprain when compared with high-quality studies (0.54 vs 11.55 per 1,000 exposures). Ankle sprain prevalence period estimates were similar across sub-groups. Lateral ankle sprain was the most commonly observed type of ankle sprain.

CONCLUSIONS

Females were at a higher risk of sustaining an ankle sprain compared with males and children compared with adolescents and adults, with indoor and court sports the highest risk activity. Studies at a greater risk of bias were more likely to underestimate the risk of ankle sprain. Participants were at a significantly higher risk of sustaining a lateral ankle sprain compared with syndesmotic and medial ankle sprains.

A large-scale study on epidemiology and risk factors for chronic ankle instability in young adults

Up to 40% of ankle sprains can result in chronic ankle instability (CAI). The prevalence of CAI and its association with body mass index (BMI) and height in the general young adult population has not been reported. The database records of young adults before recruitment into mandatory military service were studied. Information on the disability codes associated with CAI was retrieved. Logistic regression models were used to assess the association between the BMI and body height with various grades of CAI severity. The study cohort included 829,791 subjects (470,125 males and 359,666 females). The prevalence was 0.7% for mild CAI and 0.4% for severe instability in males and 0.3% and 0.4%, respectively, for females (p < .001). An increased BMI was associated with ankle instability in males (overweight, odds ratio [OR] 1.249, p < .001; obese, OR 1.418, p < .001) and females (overweight, OR 1.989 p < .001; obese, OR 2.754, p < .001). The body height was associated with an increased risk of CAI when the highest height quintile was compared with the lowest height quintile in both males (OR 2.443, p < .001) and females (OR 1.436, p < .001) for all levels of instability severity. The present study has shown a greater prevalence of CAI among males than females in a general healthy young adult population. CAI was associated with an increased BMI and greater body height for all grades of instability severity.

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

Background

Ankle 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 secondary prevention of ankle sprains.

Aim

To evaluate the effectiveness of combined bracing and neuromuscular training, or bracing alone, against the use of neuromuscular training on recurrences of ankle sprain after usual care.

Methods

384 athletes, aged 18–70, who had sustained a lateral ankle sprain, were included (training group n=120; brace group n=126; combi group n=138). The training group received an 8-week home-based neuromuscular training programme, the brace group received a semirigid ankle brace to be worn during all sports activities for 12 months, and the combi group received both the training programme, as well as the ankle brace, to be worn during all sports activities for 8 weeks. The main outcome measure was self-reported recurrence of the ankle sprain.

Results

During the 1-year follow-up, 69 participants (20%) reported a recurrent ankle sprain: 29 (27%) in the training group, 17 (15%) in the brace group and 23 (19%) in the combi group. The relative risk for a recurrent ankle sprain in the brace group versus the training group was 0.53 (95% CI 0.29 to 0.97). No significant differences were found for time losses or costs due to ankle sprains between the intervention groups.

Conclusions

Bracing was superior to neuromuscular training in reducing the incidence but not the severity of self-reported recurrent ankle sprains after usual care.

Intrinsic Predictive Factors of Noncontact Lateral Ankle Sprain in Collegiate Athletes: A Case-Control Study

BACKGROUND

Lateral ankle sprain (LAS) is one of the most common injuries in sports. Despite extensive research, intrinsic factors that predict initial and recurrent noncontact LAS remain undefined.

PURPOSE

To identify the predictive factors of initial and recurrent noncontact LAS, focusing on ankle flexibility and/or alignment in collegiate athletes.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 191 athletes were assessed during the preseason for factors predictive of noncontact LAS. The baseline measurements included weightbearing dorsiflexion range of motion (ROM), leg-heel angle, foot internal rotation angle in plantar flexion, classification according to the mortise test, and navicular-medial malleolus (NMM) distance. Occurrence of noncontact LAS and participation in practice and games were prospectively recorded for 11 months.

RESULTS

Of the 191 athletes assessed, 169 (145 males, 24 females) completed the study; 125 athletes had a history of ankle sprain. During the observational period, 16 athletes suffered noncontact LAS (0.58 per 1000 athlete-exposures) consisting of 4 initial sprains and 12 recurrences. The hazard ratio estimated by a Cox regression analysis showed that athletes with an NMM distance ≥4.65 cm were 4.14 times more likely to suffer an initial noncontact LAS than were athletes with a shorter NMM distance (95% confidence interval, 1.12-14.30) and that athletes with a weightbearing dorsiflexion ROM >49.5° were 1.12 times as likely to suffer a recurrent noncontact LAS compared with athletes with a lower ROM (95% confidence interval, 1.05-1.20).

CONCLUSION

NMM distance predicts initial noncontact LAS, and weightbearing dorsiflexion ROM predicts recurrent noncontact LAS.

High medial plantar pressures during barefoot running are associated with increased risk of ankle inversion injury in Royal Marine recruits

BACKGROUND

Ankle inversion injury is common in military populations but associated biomechanical risk factors are largely unknown. This prospective study examined the association between pressure and kinematic variables, and ankle inversion injury risk in Royal Marine (RM) recruits. It was hypothesised that a more medially concentrated pressure at the heel-off phase of stance, greater impulse and peak pressure at the first metatarsal head, greater peak rearfoot eversion angle and greater eversion excursion would be associated with ankle inversion injury.

METHODS

Data from 145 male, injury-free RM recruits were recorded in week-2 of a 32-week military training programme. Each recruit completed five running trials at 3.6 ms(-1), along a 2m pressure plate. Kinematic data were simultaneously recorded. Injuries sustained during the training programme were prospectively recorded.

FINDINGS

Data from eleven recruits who had suffered an ankle inversion injury during RM training were compared with 20 uninjured controls. The injury group displayed a higher (P<0.05) peak first metatarsal pressure, peak metatarsal impulse and more medially concentrated pressure at heel-off than control recruits. There were no differences in kinematic variables between groups. The injury group had a lower body mass than controls (P<0.05).

INTERPRETATIONS

The findings from this study support existing literature, providing evidence that high medial concentration of vertical forces when running are associated with increased ankle inversion injury risk. This may be due to the lateral ankle ligaments being less accustomed to loading, resulting in relatively weak lateral ligaments, or ligaments less able to deal with fatigue than those of the control group.