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Free papers #7

Ankle injuries and their prevention

Chair: Evert Verhagen

#39 - The Lower-Limb Dominance Conundrum: It’s time for the OLD Test

Presenting Author: Andrew Mitchell

Authors & Affiliations: Andrew Mitchell(1)
(1)   School for Sport Science and Physical Activity, Institute for Sport & Physical Activity Research, University of Bedfordshire

Background: Lower-limb dominance is commonly used within the literature to differentiate between limbs in studies examining injury prevention and prehabilitation protocols, rehabilitation from injury or surgical intervention and in assessment of functional performance. The influence of lower-limb dominance on performance measures such as hamstring:quadriceps strength ratios, single-leg vertical jump, vertical ground reaction forces and hop for distance varies across the literature. The definitions of lower-limb dominance vary and the assessment methods used to identify dominance are unrelated to the functional tasks, populations or specific injury being examined. As definitions are inconsistent, the influence of lower-limb dominance may be over or underestimated.

Objective(s): To develop a standardised lower-limb dominance assessment test and to evaluate the reliability of the test.

Design & Methods: To date, 38 physically active university students (19 males, 19 females) have participated in the study. Participants completed the Objective Lower-Limb Dominance (OLD) test in a sports hall on two occasions, one week apart. The OLD test comprises of a series of 15 lower-limb functional tasks undertaken by each participant. The primary investigator recorded the participants’ lower-limb lateral preference for each task. Test-retest reliability was evaluated using intra-class correlation coefficients (2,1) for each component and the total score between test days 1 and 2.

Results: In order to secure an appropriate sample size, we intend to evaluate 75 participants, which will meet the minimum standard of subject-to-variable ratio of 5. Therefore, the results at this point are an insight into 38 participants, however, initial evaluation suggests high intra-class correlation coefficients (2,1), with high reliability of the individual tasks and the OLD test as a whole. 
NB: We will have the remaining participants tested and the final data set complete by the end of July. And would be happy to submit an updated abstract at that point if required by the Symposium Panel.

Conclusions: The OLD test looks to address the need for a standardised lower-limb dominance assessment test, which will enable the results from studies to be more easily compared by clinicians and researchers, as currently the varying methods of assessing lower-limb dominance within the literature are inconsistent.

 

#40 - Mechanical Characterisation of the Lateral Collateral Ligament Complex of the Ankle Under Realistic Sprain-like Strain Rates

Presenting Author: David Rochelle

Authors & Affiliations: David Rochelle(1), Anthony Herbert(1), Ioannis Ktistakis(2), Anthony Redmond(3,4,5), Graham Chapman(3,4), Claire Brockett(1)
(1)   Institute of Medical and Biological Engineering, University of Leeds, Leeds, LS2 9JT, England
(2)    Chapel Allerton Hospital, Chapeltown Road, Leeds, LS7 4SA, England
(3)    Institute for Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, UK 
(4)    NIHR Leeds Biomedical Research Centre, Leeds, UK 
(5)    Arthritis Research UK Centre for Sports, Exercise and Osteoarthritis, Nottingham, Oxford, Loughborough, Leeds, UK

Background: Previously, only the anterior talofibular ligament of the lateral collateral ligament complex has been mechanically characterised at a strain-rate representative of sprain. Therefore, the requirements of synthetic interventions used to treat severe ankle sprains are not well understood. Synthetic devices are most commonly used as a repair when an initial Broström-Gould procedure has failed or the patient has a high body mass index (BMI), generalised ligament laxity or is an elite athlete.

Objective(s): This exploratory study aims to improve understanding of the mechanical properties and failure modes of the lateral collateral ligament complex at strain rates representative of sprain and, in turn, further inform the development of synthetic interventions to lateral ankle sprain.

Design & Methods: The lateral collateral ligaments were dissected from six human cadavers producing bone-ligament-bone specimens for each ligament of the intact complex. A mechanical testing device was used to uni-axially load the ligaments in tension. Initially 15 cycles of preconditioning were performed between two Newtons and a load value corresponding to 3.5 % strain, before extension to failure at a strain rate of 100% per second. The results were stratified by age, weight and BMI to explore potential correlations with ligament ultimate failure load or ligament stiffness.

Results: The mean ultimate failure loads and the 95% confidence intervals for the anterior talofibular, calcaneofibular and posterior talofibular ligaments were 351.4 ± 110.8 N, 367.8 ± 79.8 N and 263.6 ± 164.3 N, respectively. A strong positive Pearson correlation was found between BMI and ultimate failure load of the calcaneofibular and posterior talofibular ligaments (r = .919; P = .01, r = .65; p = .16, respectively). The anterior talofibular ligament avulsed from the fibula four times, the calcaneofibular ligament avulsed from the fibula twice, the posterior talofibular ligament avulsed from the talus twice and all remaining failures were mid-substance.

Conclusions: The ultimate failure load, stiffness and failure mode results can improve specifications for synthetic ankle ligament development to improve ankle joint functionality. A correlation between BMI and the ultimate failure load of the calcaneofibular ligament and posterior talofibular ligament may exist, although a greater sample size is required for confirmation.

 

#41 - Using functional electrical stimulation to alter lateral ankle sprain risk

Presenting Author: Zoe Bamber

Authors & Affiliations: Zoe Bamber(1), Patrick Wheeler(1), Daniel Fong(1)
(1)   School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK

Background: Ankle sprain is the most common type of ankle injury accounting  for 5,600 A and E visits a day (Fong et al., 2007;Doherty et al., 2014;Cooke et al., 2009). Research has shown a lateral shift of plantar pressure with the foot in a more inverted position increases risk of ankle inversion sprains (Willems et al 2005, Hiller et al 2012, Doherty et al 2014, Nyska et al 2003, Becker et al 1997, Natawa 2005, Morrison et al 2010, Kobayashi 2014, Delahunt et al 2014, Monaghan et al 2006, Schmidt et al 2011). No research to date appears to investigate whether retraining using electrical stimulation to change centre of pressure could effectively reduce an individual’s risk of lateral ankle sprain via changing their centre of pressure during running. 

Objective(s): The  objective of this research is to identify whether the initial effect of training using functional electrical stimulation to stimulate the peroneal muscles  can alter the Centre of pressure during running gait to a more medial position and therefore potentially mitigating the risk of sport related ankle inversion ligamentous sprain.

Design & Methods: This is a single blinded randomised control trial that compared the initial effect of functional electrical stimulation on centre of pressure in individuals with a lateral deviation using Novel inshoe pressure system.  Individuals were exposed to an individualised level of stimulation to the peroneal muscles whilst carrying out a 15-minute run on a treadmill. Pre and post centre of pressure distribution of whole foot was compared. A Wilcoxon rank test was carried out using SPSS to analyse if there is a difference seen pre and post intervention in both the control and intervention groups.

Results: A Wilcoxon rank test indicated that the control group centre of pressure pre intervention was not statistically different than centre of pressure post intervention z=-0.135 P=0.447; the sum on the negative and positive ranks are also almost equal. The Wilcoxon rank test indicated that in the intervention group there is not a statistically significant difference pre and post intervention, though was approaching significance with z=-1.334, P=0.09. The sum of negative and positive results show a much larger sum of positives indicating that the intervention results in more positive results therefore meaning a more medial centre of pressure post intervention. 

Conclusions: Overall change in foot pressure indicates a more medial distribution post intervention, though results are not significant, this may become more apparent with a larger sample size. The use of FES as a preventative strategy for LAS is a possibility in the future though further research is required.

 

#42 - Kinematic Analysis of a Televised Lateral Ankle Sprain Injury in Badminton

Presenting Author: Isobel Thompson

Authors & Affiliations: Isobel Thompson(1,2), Kam-Ming Mok(3), Daniel Fong(1)
(1)   School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
(2)    School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
(3)    Department of Orthopaedics and Traumatology, Prince of Wales Hospital, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China

Background: Ankle ligamentous sprains have been reported as one of the most commonly occurring injuries within sport, with lateral ankle sprains being the most common of these. Previously, indirect methods have been used to explain the injury mechanics of lateral ankle sprain injuries, but are unable to provide data relating directly to a real injury scenario. The Model-Based Image-Matching method allows a quantitative analysis to be carried out on real injury cases. This analysis technique will help to develop the understanding of injury mechanisms in the future.

Objective(s): The aim of this study is to determine the injury mechanism for a televised injury of a badminton player, using a unique camera view to enable detailed matching of the model to the player. It is hoped that the results reported will add to the existing body of research.

Design & Methods: This case study uses a Model-Based Image-Matching method to quantify the injury mechanics of a televised lateral ankle sprain injury, comparing the findings to the existing body of research. Four camera views which captured the injury were selected, including one which provided a linesman’s view. Each of these videos was transformed and synchronised, and then opened in an animation software package. The known court dimensions were matched, creating a virtual environment, after which a skeletal model was matched to the athlete’s motion frame by frame. Initial foot contact was determined through visual inspection. The kinematic profiles are presented.

Results: The kinematic profile of this case was similar to those previously reported within the literature. A pattern of high inversion in combination with internal rotation was observed, with peak inversion and internal rotation measured at 123° and 65° respectively. The peak inversion velocity recorded was 1469 deg/s. The onset of the injury phase was identified at 0.12 s after initial foot contact. The peak angles and velocities observed were within the range of values recorded within the previous Model-Based Image-Matching literature.

Conclusions: This study successfully provides a quantitative kinematic analysis of a lateral ankle sprain injury mechanism. It is suggested that an at-risk ankle orientation combined with a high velocity of movement is the cause of the injury in this case. The excessive joint motion observed is a consequence of this.

 

#43 - Dynamic balance and ankle injury risk: a prospective study in 196 PETE students

Presenting Author: Sander Bliekendaal

Authors & Affiliations: Sander Bliekendaal(1), Janine Stubbe(2), Evert Verhagen(3)

(1)   Amsterdam University of Applied Sciences, Centre for Applied Research in Sports and Nutrition
(2)    Codarts University of the Arts, Rotterdam, The Netherlands
(3)    Amsterdam Collaboration on Health and Safety in Sports & Department of Public and Occupational Health, Amsterdam Movement Science, VU University Medical Center, Amsterdam, the Netherlands

Background: Ankle injuries are one of the most common injuries in Physical Education Teacher Education (PETE) students. Identifying risk factors for ankle injuries is of importance in the development of injury prevention programs.

Objective(s): The aim of this study was to investigate the relationship between dynamic balance of the ankle and ankle injury risk in first-year Dutch PETE students.

Design & Methods: This prospective study consisted of measures of the anterior component of the Starr Excursion Balance Test (SEBT-ANT) at baseline (September 2015) and an injury registration procedure during a follow-up period (September 2015 – June 2016). In total 196 subjects were included in the study, of which 137 men (70%) and 59 women (30%). The association between the SEBT-ANT score and subsequent ankle injury was analyzed with Generalized Estimating Equations analysis at the leg level.

Results: Men and women had an average anterior reach of respectively 65.1% and 67.7% of leg length. In 20 (15%) subjects the first injured body site involved the ankle. In men, a below average SEBT-ANT score indicated a 7-fold risk for ankle injury (Odds Ratio [OR] = 7.06, 95% Confidence Interval [CI]: 1.43 – 34.92, p = .02). In women, this relationship was not significant (OR = 0.72, 95% CI: 0.19 – 2.71, p = .62).

Conclusions: Below average normalized SEBT-ANT scores were associated with a 7-fold risk for subsequent ankle injuries in men. These results may provide directions in the design of an injury prevention program.