Selection criteria for patients with chronic ankle
instability in controlled research: a position
statement of the International Ankle Consortium
Phillip A Gribble,
1
Eamonn Delahunt,
2
Chris Bleakley,
3
Brian Caulfield,
4
Carrie Docherty,
5
François Fourchet,
6
Daniel Tik-Pui Fong,
7
Jay Hertel,
8
Claire Hiller,
9
Thomas Kaminski,
10
Patrick McKeon,
11
Kathryn Refshauge,
9
Philip van der Wees,
12
Bill Vincenzino,
13
Erik Wikstrom
14
1
University of Toledo, Toledo,
Ohio, USA
2
School of Public Health,
Physiotherapy and Population
Science, University College
Dublin, Dublin, Ireland
3
Univerisity of Ulster,
Jordanstown, Carrickfergus, UK
4
School of Physiotherapy,
University College Dublin,
Dublin, UK
5
University of Indiana,
Bloomington, Indiana, USA
6
Qatar Orthopaedic and Sports
Medicine Hospital, Doha, Qatar
7
Department of Orthopaedics
and Traumatology, The Chinese
University of Hong Kong, Hong
Kong, China
8
Kinesiology Program,
University of Virginia,
Charlottesville, Virginia, USA
9
Department of Physiotherapy,
University of Sydney, Sydney,
New South Wales, Australia
10
Department of Health,
Nutrition and Exercise
Sciences, University of
Delaware, Newark, New Jersey,
USA
11
Department of Rehabilitation
Sciences, University of
Kentucky, Lexington, Kentucky,
USA
12
Radboud University Nijmegen
Medical Centre, Nijmegen
Area, Netherlands
13
Department of Physiotherapy,
University of Queensland,
Brisbane, Queensland,
Australia
14
University of North Carolina,
Charlotte, North Carolina, USA
Correspondence to
Dr Phillip Gribble, University of
Toledo, Mailstop #119 2801
W. Bancroft, Toledo,
OH 43606, USA;
phillip.gribble@utoledo.edu
Accepted 10 October 2013
Published Online First
19 November 2013
To cite: Gribble PA,
Delahunt E, Bleakley C,
et al. Br J Sports Med
2014;48:1014–1018.
ABSTRACT
While research on chronic ankle instability (CAI) and
awareness of its impact on society and health care
systems has grown substantially in the last 2 decades,
the inconsistency in participant/patient selection criteria
across studies presents a potential obstacle to addressing
the problem properly. This major gap within the
literature limits the ability to generalise this evidence to
the target patient population. Therefore, there is a need
to provide standards for patient/participant selection
criteria in research focused on CAI with justifications
using the best available evidence. The International
Ankle Consortium provides this position paper to present
and discuss an endorsed set of selection criteria for
patients with CAI based on the best available evidence
to be used in future research and study designs. These
recommendations will enhance the validity of research
conducted in this clinical population with the end goal
of bringing the research evidence to the clinician and
patient.
EPIDEMIOLOGY AND IMPACT OF ANKLE
INJURY
Injuries to the ankle joint account for 20% of the
population that is afflicted with joint injury.
1
There
are more than three million emergency room visits
annually for ankle/foot injuries in the USA,
2
and
the largest percentage of self-reported musculoskel-
etal injuries (> 10%) are to the ankle.
3
More than
628 000 ankle injuries, including ankle sprains and
fractures, per year are treated in USA emergency
rooms, accounting for 20% of all injuries treated in
emergency facilities.
4
Ankle sprains account for an
estimated 3–5% of emergency room visits in the
UK,
5
representing a significant amount of devoted
healthcare resources. Additionally, it is estimated
that as many as 55% of patients who sustain an
ankle sprain do not seek evaluation or treatment
from a healthcare professional.
6
Subsequently, the
reporting of traumatic ankle sprains may be grossly
under-reported in healthcare statistics.
SHORT-TERM AND LONG-TERM SEQ UELAE
Traumatic ankle injury represents a significant health-
care issue. Of further significance is that ankle sprains
have a high rate of recurrence (as high as 80% in
high-risk sports).
7–9
Recent data indicate that ankle
sprains are not just an innocuous injury primarily
incurred by young athletes; rather, they also impact
approximately 8% of the general population who
report persistent symptoms following an initial ankle
sprain.
10
Chronic joint injury and degeneration is
associated with over US$3 billion in annual health-
care costs in the USA.
11
Evidence for the relationship
between acute and recurrent ankle joint trauma and
the development of post-traumatic ankle joint osteo-
arthritis (OA) is growing.
11 12
Saltzman et al
13
have
reported that as many as four in five cases of ankle
joint OA are the result of previous musculoskeletal
trauma, with these patients being on average a
decade younger than patients with primary ankle
joint OA. Additionally, self-reported disability using
the SF-36 physical component score was significantly
lower in patients with ankle OA from the USA
13
as
compared with the general population, and was also
equal to or lower compared with patients with end-
stage kidney disease,
14
chronic heart failure
15
or
Parkinson’s disease.
16
Therefore, ankle joint sprains
and its associated sequelae affect individuals across
the lifespan and represent a large healthcare burden.
Advances in research
The prevalence and impact of ankle sprains on
society and healthcare systems support the need for
continued research related to the prevention, treat-
ment and rehabilitation of ankle sprains and their
associated sequelae. As aforementioned, an unfor-
tunate and prominent consequence of acute ankle
sprains is a very high recurrence rate. It has been
reported that 32–74% of individuals with a history
of ankle sprain have some type of residual and
chronic symptoms, recurrent ankle sprains and/or
perceived instability.
17 18
Evidence from peer-
reviewed literature suggests that the characteristics
of patients with recurrent ankle injury are not
homogeneous. Many categorical descriptions have
been used to define this pathology, including
chronic ankle instability (CAI), functional ankle
instability, mechanical ankle instability (MAI) and
recurrent ankle instability.
19–21
CAI has been
defined in a variety of ways, but is most predomin-
antly described ‘as an encompassing term used to
classify a subject with both mechanical and func-
tional instability of the ankle joint.’
20
International Ankle Consortium position
statement
The International Ankle Consortium is an inter-
national community of researchers and clinicians
Editor’s choice
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Con s en su s stat em en t
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whose primary scholastic purpose is to promote scholarship and
dissemination of research informed knowledge related to path-
ologies of the ankle complex. The constituents of the
International Ankle Consortium and other similar organisations
have yet to properly define the clinical phenomenon known as
CAI and its related characteristics for consistent patient recruit-
ment and advancement of research in this area. While research
on CAI and awareness of its impact on society and healthcare
systems have grown substantially in the last two decades, the
inconsistency in participant/patient selection criteria across
studies presents a potential obstacle to addressing the problem
properly. This major gap within the literature limits the ability
to generalise this evidence to the target patient population.
Therefore, there is a need to provide standards for patient/par-
ticipant selection criteria in research focused on CAI with justifi-
cations using the best available evidence. The primary rationale
for documenting such standards is to outline specific inclusion
criteria that should be reported on as a minimum when con-
ducting research in the area of CAI. This will be of particular
importance as research into CAI continues to grow and become
more sophisticated, especially to enable high-fidelity synthesis
and meta-analyses of data through future systematic reviews.
Although CAI is a multifaceted condition, there have been
research developments to capture functional deficits associated
with those who have recurrent issues. Freeman et al
22
were
among the first to recognise measurable differences in clinical
outcomes in patients who had a history of ankle joint injury.
Recognition of prolonged deficits in single-limb balance after
ankle ligament sprains led to a theory of changes in neural sig-
nalling following trauma to the ankle joint and categorisation of
these patients as having functional ankle instability. Several
decades later, Hertel
19
presented a model that recognised the
contributions from functional and mechanical insufficiencies
associated with an acute ankle sprain that may interact to pre-
cipitate the development of CAI. The development of this
model was a seminal step in facilitating an understanding of
why many patients incur repeated ankle joint dysfunction. The
use of the term CAI according to the Hertel
19
model repre-
sented the initial attempt to define and provide potential contri-
butions from functional and mechanical insufficiencies, which
helped develop a more comprehensive approach to researching
and treating individuals with this pathology.
Research related to ankle joint instability evolved over the
decade following the publication of the Hertel
19
CAI model,
with a primary aim of much of the research devoted to under-
standing exactly what combinations of functional and mechan-
ical insufficiencies best define CAI. Many recent reviews and
multifactorial studies have provided important information out-
lining that there are multiple potential contributing mechanical,
neuromuscular, functional and/or perceived deficits that may
persist long after physiological tissue healing times have elapsed
and interventions have been completed following an acute ankle
joint sprain.
23–34
Consistently, these reviews and multifactorial
studies support the proposition that CAI is a multifaceted and
complex condition requiring a further in-depth interdisciplinary
study.
Although the volume and quality of this research grew sub-
stantially, it became more evident that individuals with CAI are
quite heterogeneous in their presentation of impairments,
leading the research towards consideration of a possible con-
glomeration of subgroups. Recently, Hiller et al
21
introduced
an update of Hertel’s
19
CAI model that suggests that there may
be as many as seven different subsets of patients who incur
persistent symptoms following an initial ankle joint sprain,
which are dependent on the complex interaction of mechanical
insufficiencies, perceived instability and frequency of recurrent
sprains.
Rationale
When one examines the body of work related to repeated and
recurrent ankle joint injury and instability, there is a spectrum of
patient characteristics that have been used within the ankle
instability (including CAI and functional ankle instability)
research literature from the past two decades.
20 21
Delahunt
et al
20
systematically investigated these issues in the research
relating to recurrent ankle joint sprain and the resulting incon-
sistent definitions and use of terms such as CAI, functional
ankle instability, etc. They concluded that CAI was the most
commonly used term to describe individuals who report
ongoing symptoms after an initial ankle sprain; and the most
commonly reported deficits associated with CAI were frequent/
recurrent sprains and episodes of or the reporting of feelings of
ankle joint ‘giving way’. Subsequently, the authors advocated
that research in this area could be improved if consistent termin-
ology and a specific set of patient selection criteria could be
established.
Statement objectives
It is the opinion of the International Ankle Consortium that
some of the inconsistency in defining the factors and characteris-
tics that best explain recurrent ankle sprains and instability may
be attributed to inconsistent inclusion criteria among this litera-
ture. The International Ankle Consortium proposes the estab-
lishment of an accepted set of selection criteria, which should
be used in this area of research, as it will provide consistency to
the future data synthesis devoted to improving the understand-
ing of CAI and enhancing the external validity of findings for
this patient population. The purpose of this position statement
is to present and discuss an endorsed set of selection criteria for
patients with CAI based on the best available evidence to be
used in future research and study designs. Our group wishes to
advocate the pursuit of the strongest and most appropriate evi-
dence that will improve the understanding and management of
CAI.
CRITERIA RECOMMENDATIONS
The standard inclusion and exclusion criteria endorsed by the
International Ankle Consortium, as a minimum, for enrolling
patients who fall within the heterogeneous condition of CAI in
controlled research are listed in boxes 1 and 2. Additionally, the
International Ankle Consortium encourages the reporting of
critical information found in table 1 for patients with CAI to
provide a comprehensive description of the study participants
who have been enrolled in controlled research studies.
DISCUSSION
The preceding endorsed criteria for selection of individuals with
CAI in research are based on the best available evidence, and
the International Ankle Consortium recommends adherence to
produce consistent population characteristics for improved out-
comes and external validity in future research of this clinical
phenomenon. These recommendations will enhance the validity
of research conducted in this clinical population with the end
goal of bringing the research evidence to the clinician and
patient. Additional rationale for the selection criteria will be
provided below.
The International Ankle Consortium acknowledges the work
of Delahunt et al
20
that has provided the framework for this
2 of 6 Gribble PA, et al. Br J Sports Med 2014;48:1014–1018. doi:10.1136/bjsports-2013-093175
Consensus statement
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on August 9, 2022 at India:BMJ-PG Sponsored. Protectedhttp://bjsm.bmj.com/Br J Sports Med: first published as 10.1136/bjsports-2013-093175 on 19 November 2013. Downloaded from
position statement and recommends consultation of and familiar-
isation with that work by all researchers with an interest in CAI.
The aims of the systematic investigation by Delahunt et al
20
were to: (1) identify the definition of ankle instability used by
authors publishing research papers pertaining to ankle joint
sprain and its subsequent sequelae; (2) identify the terminology
used by authors to classify patients with CAI (eg, CAI, functional
ankle instability, MAI or others) and (3) to identify the specific
inclusion criteria used by authors publishing research papers per-
taining to ankle joint sprain and subsequent sequelae. This was
the first published paper to systematically investigate the afore-
mentioned issues which may lead to inconsistencies in research
results relating to ankle joint sprain and its subsequent sequelae.
The results of this systematic investigation indicated that CAI was
the most commonly used term to describe patients who report
ongoing symptoms after an initial ankle sprain. Furthermore, the
most commonly used descriptors relating to CAI were frequent/
recurrent sprains and episodes of or the reporting of feelings of
ankle joint ‘giving way’. Based on their findings, Delahunt et al
20
recommended that consistent terminology and a specific
minimum set of criteria be reported as this would improve
research endeavour pertaining to CAI. As such, Delahunt et al
20
devised a set of operational definitions related to ankle joint
sprain and its subsequent sequelae, as well as a specific set of cri-
teria that should be reported when undertaking research on indi-
viduals with CAI. These definitions and criteria set formed the
basis of discussion at the International Ankle Symposium, from
which the International Ankle Consortium formed a consensus
statement relating to the operational definitions pertaining to
ankle joint sprain and its subsequent sequelae and a minimum set
of criteria to be reported when conducting CAI research.
At the fifth International Ankle Symposium (Lexington,
Kentucky, USA, 2012), the International Ankle Consortium
executive committee discussed the concepts of this position
paper based on the existing work and the new information
being presented at the meeting.
35
Consistent with the work by
Box 1 Standard inclusion criteria endorsed, as a
minimum, by the International Ankle Consortium for
enrolling patients who fall within the heterogeneous
condition of chronic ankle instability in controlled
research.
Inclusion criteria
1. A history of at least one significant ankle sprain
▸ The initial sprain must have occurred at least 12 months
prior to the study enrolment
▸ Was associated with inflammatory symptoms (pain,
swelling, etc)
▸ Created at least one interr upted day of desired physical
activity
The most recent injury must have occurred more than 3 months
prior to the study enrolment.
We endorse the definition of an ankle sprain as “An acute
traumatic injury to the lateral ligament complex of the ankle
joint as a result of excessive inversion of the rear foot or a
combined plantar flexion and adduction of the foot. This usually
results in some initial deficits of function and disability”.
20
2. A history of the previously injured ankle joint ‘giving way’,
and/or recurrent sprain and/or ‘feelings of instability’.
We endorse the definition of ‘giving way as “The regular
occurrence of uncontrolled and unpredictable episodes of
excessive inversion of the rear foot (usually experienced during
initial contact during walking or running), which do not result in
an acute lateral ankle sprain”.
20
Specifically, participants should report at least 2 episodes of
‘giving way’ in the 6 months prior to the study enrolment.
We endorse the definition of ‘recurrent sprain’ as “Two or
more sprains to the same ankle”.
20
We endorse the definition of feeling of ankle joint instability
as “The situation whereby during activities of daily living (ADL)
and sporting activities the subject feels that the ankle joint is
unstable and is usually ass ociated with the fear of sustaining an
acute ligament sprain”.
20
Specifically, self-reported ankle instability should be confirmed
with a validated ankle instability-specific questionnaire using the
associated cut-off score. Currently recommended questionnaires:
A. Ankle Instability Instrument (AII)
40
: answer ‘yes’ to at
least five yes/no questions (This should include question
1, plus four others)
B. Cumberland Ankle Instability Tool (CAIT)
41
: score of <24
C. Identification of functional ankle instability (IdFAI)
37
:
score of >11
3 A general self-reported foot and ankle function questionnaire
is recommended to describe the level of disability of the
cohort, but should only be an inclusion criterion if the level
of self-reported function is important to the research
question. Currently endorsed questionnaires:
A. Foot and Ankle Ability Measure (FAAM)
42
: ADL scale
<90%; Sport scale <80%
B. Foot and Ankle Outcome Score (FAOS)
43
: score of <75%
in three or more categories
Box 2 Standard exclusion criteria endorsed, as a
minimum, by the International Ankle Consortium for
enrolling patients who fall within the heterogeneous
condition of chronic ankle instability in controlled
research.
Exclusion criteria
1. A history of previous surgeries to the musculoskeletal
structures (ie, bones, joint structures and nerves) in either
lower extremity.
It is understood and accepted in clinical and research practice
that surgery to repair insufficient joint structures is designed to
restore structural integrity, but creates residual changes in the
central and peripheral portions of the nervous system. Even with
appropriate rehabilitation and follow-up management, there are
concomitant neuromuscular and structural alterations after
surgery that would confound the ability to isolate the effects of
chronic ankle instability.
2. A history of a fracture in either lower extremity requiring
realignment.
Similar to the first exclusion criterion, significant compromise to
skeletal tissue will threaten the internal validity of the selection
of study populations with isolated chronic ankle instability.
3. Acute injury to the musculoskeletal structures of other joints
of the lower extremity in the previous 3 mo nths, which
impacted joint integrity and function (ie, sprains, fractures)
resulting in at least 1 interrupted day of desired physical
activity.
Gribble PA, et al. Br J Sports Med 2014;48:1014–1018. doi:10.1136/bjsports-2013-093175 3 of 6
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Delahunt et al,
20
new papers presented at the International
Ankle Symposium emphasised the strength of the reported epi-
sodes of ‘giving way’ and patient-reported instability in defining
CAI. Snyder et al,
36
using the Delphi method to gather input
from expert clinicians and researchers, reported that the ‘recur-
rent sense of giving way’ was the strongest characteristic in
defining CAI. However, there are other characteristics such as
feelings of instability and recovery from a ‘rolling over’ inci-
dent
37
that are important in identifying who has CAI and estab-
lishing the severity of the condition that is not obtained through
the reporting of ‘giving way’ alone. A series of studies
38 39
support the use of condition-specific self-report questionnaires
to identify those with the minimal accepted criteria for ankle
instability. It is critical to use condition-specific questionnaires
that are both valid and reliable
37 40 41
in the collection of this
information. This recent work highlights the increasing evidence
for the selected criteria we introduced in this position paper.
Additionally, measurement of self-reported instability should
be differentiated from measurement of resulting change to phys-
ical function or quality of life. Changes to physical function
may be a result of any or all mechanical insufficiencies, self-
reported instability and recurrent sprains. Therefore, if investi-
gators are interested in the deficits present in participants with
CAI, such as strength, neuromuscular or proprioception deficits
as examples, measures of self-reported function may not be a
necessary inclusion criterion for this type of study. However, if
functional impairment is relevant to the proposed project or
intervention, then validated ankle-specific questionnaires that
were designed to evaluate self-reported function should be used
to create the necessary inclusion criterion.
42 43
Our recommended inclusion criteria are based on assessments
of injury history, function and disability, but we recognise the
lack of a definitive selection criteria based on an assessment of
joint integrity or laxity. While an initial ankle sprain often threa-
tens the integrity of ligamentous structures and some authors
have reported lingering ankle laxity, hypomobility and hypermo-
bility, these outcomes do not appear to be observed consistently
in patients with CAI. Previous authors have considered mechan-
ical instability as an explanatory factor for lingering ankle
instability, but there has not been a definitive association of
ankle laxity with CAI.
19–21 23 28 29 33 44 45
Hertel’s
19
original model differentiated mechanical instability
from functional instability. More recently, Hiller et al,
21
refining
the model of categorising CAI, suggests as many as seven
subgroups of individuals with CAI who most likely provide
better homogeneity in describing the pathology. Of the three
primary separation factors, the authors suggested that mechan-
ical instability provided the weakest contribution. Additionally,
hypomobility, rather than joint laxity, contributes more to the
subgroup model creation. It appears that mechanical instability
may be a factor in some patients that leads to recurrent ankle
injury and measures of perceived ankle instability, but these are
not necessarily dependent on the presence of ankle hypermobi-
lity. Data from other multifactorial studies that have included
measures of mechanical instability in patients with CAI suggest
that mechanical instability alone is not a consistent identifier of
this pathology.
28 33
A recent advancement in the CAI literature has been the
stratification of individuals based on the structural and func-
tional impairments associated with ankle instability. Multiple
studies by Brown et al
44–46
compared sensorimotor and bio-
mechanical measures between patients classified as having MAI,
functional ankle instability and copers (no measurable ankle
instability or repeated injury). While the presence of mechanical
laxity was associated with some proximal joint sensorimotor
alterations and increases in ground reaction forces during
landing tasks compared with the other groups, these differences
were not observed consistently. It is also interesting to note that
the MAI groups had more self-reported disability and no differ-
ences in the number of episodes of ‘giving way’ as compared
with the functional ankle instability groups, suggesting that the
MAI groups had similar, if not more, functional instability than
the functional ankle instability groups did. The design of these
studies to separate MAI and functional ankle instability repre-
sents the needed comparisons required to glean the factors that
best define CAI. The information would seem to lend support
to the strength of the contribution of functional instability mea-
sures, rather than mechanical instability, to de fining CAI.
Future considerations
We have provided recommendations for the selection of patients
with CAI to improve the quality of research on this pathology.
The healthcare burden associated with ankle instability necessi-
tates increased research and clinical outcomes that can be used
to reduce the disability and recurrence rates associated with
CAI. It is clear from the body of literature that there are many
contributing factors to CAI that can create a host of impair-
ments
19 20 23 26 28 29 32 33
; however, this condition is more
Table 1 Information recommended by the International Ankle Consortium for patients with chronic ankle instability with the goal of providing
a comprehensive description of the study participants who have been enrolled in controlled research studies
Topic Suggested content
Quality of ankle injury history 1. The number of previous ankle sprains
2. The presence and frequency of reported episodes of ‘giving way’
3. The presence and frequency of reported episodes of feelings of instability
4. The scores on the validated self-reported ankle instability instruments utilised to establish inclusion criteria
5. Severity of injury (index and most recent incidents), including the number of days of immobilisation and/or non-weight bearing
6. If diagnosis was performed by a healthcare professional or self-diagnosed
Timing of ankle sprain injury 7. The time since the most recent ankle sprain
8. The number of weeks of supervised rehabilitation by a healthcare professional
9. The number of weeks since supervised rehabilitation was completed
Potential confounding factors 10. Any included mechanical instability ratings (ie, clinical laxity scales, arthrometry measures and stress radiography)
11. A rating of the current level of physical activity level using a validated scale (eg, Tegner scale, Godin Leisure Time Physical Activity,
etc), and the minimum number of hours per week of participation in physical activity
12. Any concomitan t, non-surgical injuries at the time of ankle sprain13. The frequency of use of prophylactic ankle support
14. The results of any functional or range of motion assessments
15. Presence of pain during functional activities
4 of 6 Gribble PA, et al. Br J Sports Med 2014;48:1014–1018. doi:10.1136/bjsports-2013-093175
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heterogeneous than many realise.
20 21
Therefore, researchers
need to be cognisant of criteria that are best associated with CAI
based on the current available evidence. Based on the collective
expertise of the International Ankle Consortium, we feel that
the specified selection criteria should be incorporated in all
future research on CAI.
The selection criteria are based on a history of initial injury
and of ongoing bouts of instability, as well as ratings of patient
perceived function and disability gathered from validated survey
instruments. In addition, to study CAI in patients, concomitant
issues such as fracture and surgery and other significant lower
extremity joint injury should be absent; also, an appropriate
amount of time should have passed since suffering acute, inflam-
matory symptoms, all for the purpose of eliminating the con-
founding influence on the outcomes that researchers choose to
employ.
We have provided our list of additional patient information
that we feel should be reported, and we look forward to evalu-
ating and using the evidence that continues to grow from this
work to modify our recommendations moving forward. In the
future, consistency among these suggested reported measures
will only help to strengthen the description and understanding
of CAI. In the mean time, researchers should strive to report as
many of these data to create clearer descriptions of CAI, which
may lead to more homogeneous subgroups being enrolled in
studies. The rationale for this is to improve the understanding
of the consequences of repetitive ankle injury and lingering
instability, leading to the development of more effective inter-
ventions to decrease the acute and chronic ankle injury rates in
physically active populations.
Statement and background of creation of the position
statement
The International Ankle Consortium, formed in 2004, is an
international community of researchers and clinicians whose
primary scholastic purpose is to promote scholarship and dis-
semination of research informed knowledge related to patholo-
gies of the ankle complex. We are a collegial network that
strives to support the ongoing growth of scientific and clinical
evidence to elucidate the mechanisms, characteristics and inter-
ventions related to ankle complex/joint pathologies. The
International Ankle Symposium is the primary venue by which
the International Ankle Consortium disseminates the work of its
constituents in an effort to present and discuss the most contem-
porary theories and research related to ankle joint clinical phe-
nomena and related interventions, with a primary focus on CAI.
Another focus of the International Ankle Consortium is to
provide endorsement for standards of clinical research related to
ankle joint pathologies. The International Ankle Consortium
endorses the summary statements from past International Ankle
Symposia that have presented the major findings and updates
from the content of the meetings.
35 47–49
Additionally, the
International Ankle Consortium establishes position statements,
such as this one, to endorse consistent standards for research
and clinical management of ankle joint conditions among the
physically active. This position statement will provide the back-
ground and discuss the existing evidence to support a set of spe-
cific selection criteria for patients with chronic/functional ankle
instability with the goal of improving the quality of research
and outcomes related to this specific ankle condition.
Contributors This article was designed and developed in cooperation with the
members of the International Ankle Consortium Executive Committee: PAG, ED, CB,
BC, CD, FF, DT-PF, JH, CH, TK, PM, KR, PVDW, BV, EW.
Competing interests None.
Provenance and peer review Not commissioned; internally peer reviewed.
REFERENCES
1 The Bone and Joint Decade: The Burden of Musculoskeletal Diseases in the United
States [Internet]. 2008. http://www.boneandjointburden.org/pdfs/
BMUS_chpt6_injuries.pdf
2 National Center for Health Statistics, National Ambulatory Medical Care Survey,
2006 [Internet]. http://www.cdc.gov/nchs/data/nhsr/nhsr003.pdf
3 National Center for Health Statistics. National Health Interview Survey, Injury
Database, 2008 [Internet]. http://www.cdc.gov/nchs/nhis.htm
4 Waterman B, Owens B, Davey S, et al. The epidemiology of ankle sprains in the
United States. J Bone Joint Surg Am 2010; 92:2279–84.
5 Cooke M, Lamb S, Marsh J, et al. A survey of current consultant practice of
treatment of severe ankle sprains in emergency departments in the United
Kingdom. Emerg Med J 2003;20:505–7.
6 McKay G, Goldie P, Payne W, et al. Ankle injuries in basketball: injury rate and risk
factors. Br J Sports Med 2001;35:103–8.
7 Beynnon B, Murphy D, Alosa D. Predictive factors for lateral ankle sprains: a
literature review. J Athl Train 2002;37:376–80.
8 Yeung M, Chan K, So C. An epidemiological survey on ankle sprain. Br J Sports
Med 1994;28:112–16.
9 Swenson D, Yard E, Fields S, et al. Patterns of recurrent injuries among US high
school athletes, 2005–2008. Am J Sports Med 2009;37:1586–9.
10 Hiller CE, Nightingale EJ, Raymond J, et al. Prevalence and impact of chronic
musculoskeletal ankle disorders in the community. Arch Phys Med Rehabil
2012;93:1801–7.
11 Brown T, Johnston R, Saltzman C, et al. Posttraumatic osteoarthritis: a first estimate
of incidence, prevalence, and burden of disease. J Orthop Trauma
2006;20:739–44.
12 Caine DJ, Golightly YM. Osteoarthritis as an outcome of paediatric sport: an
epidemiological perspective. Br J Sports Med 2011;45:298–303.
13 Saltzman CL, Zimmerman B, O’Rourke M, et al. Impact of comorbidities on the
measurement of health in patients with ankle osteoarthritis. J Bone Joint Surg Am
2006;88A:2366–72.
14 Knight E, Ofsthun N, Teng M, et al. The association between mental health,
physical function, and hemodialysis mortality. Kidney Int 2003;63:1387–94.
15 Sneed NV, Paul S, Michel Y, et al. Evaluation of 3 quality of life measurement tools
in patients with chronic heart failure. Heart Lung 2001;30:332–40.
16 Gage H, Hendricks A, Zhang S, et al
. The relative health related quality of life of
ve
terans with Parkinson’s disease. J Neurol Neurosurg Psychiatry 2003;
74:163–9.
17 Anandacoomarasamy A, Barnsley L. Long term outcomes of inversion ankle injuries.
Br J Sports Med 2005;39:e14.
18 Konradsen L, Bech L, Ehrenbjerg M, et al. Seven years follow-up after ankle
inversion trauma. Scand J Med Sci Sports 2002;12:129–35.
19 Hertel J. Functional anatomy, pathomechanics, and pathophysiology of lateral ankle
instability. J Athl Train 2002;37:364–75.
20 Delahunt E, Coughlan GF, Caulfield B, et al. Inclusion Criteria When Investigating
insufficiencies in chronic ankle instability. Med Sci Sports Exerc 2010;
42:2106–21.
21 Hiller C, Kilbreath S, Refshauge K. Chronic ankle instability: evolution of the model.
J Athl Train 2011;46:133–41.
22 Freeman M. Instability of the foot after injuries to the lateral ligament of the ankle.
J Bone Joint Surg 1965;47-B:669–77.
23 Hiller CE, Ightingale EJN, Lin CWC, et al. Characteristics of people with recurrent
ankle sprains: a systematic review with meta-analysis. Br J Sports Med
2011;45:660–72.
24 Arnold B, DE LA, Motte S, et al. Ankle instability is associated with balance
impairments: a meta-analysis. Med Sci Sports Exerc 2009;41:1048–62.
25 Brinkman RE, Evans TA. History of ankle sprain as a risk factor of future lateral
ankle sprain in athletes. J Sport Rehabil 2011;20:384–8.
26 Hertel J. Sensorimotor deficits with ankle sprains and chronic ankle instability. Clin
Sports Med 2008;27:353–70.
27 Hirai D, Docherty CL, Schrader J. Severity of functional and mechanical ankle
instability in an active population. Foot Ankle Int 2009;30:1071–7.
28 Hubbard T, Kramer L, Denegar C, et al. Contributing factors to chronic ankle
instability. Foot Ankle Int 2007;28:343–54.
29 Hubbard-Turner T. Relationship between mechanical ankle joint laxity and subjective
function. Foot Ankle Int 2012;33:852–6.
30 McKeon P, Hertel J. Systematic review of postural control and lateral ankle
instability, part I: can de
ficits
be detected with instrumented testing. J Athl Train
2008;43:293–304.
31 Munn J, Sullivan S, Schneiders A. Evidence of sensorimotor deficits in functional
ankle instability: a systematic review with meta-analysis. J Sci Med Sport
2010;13:2–12.
Gribble PA, et al. Br J Sports Med 2014;48:1014–1018. doi:10.1136/bjsports-2013-093175 5 of 6
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