The medial longitudinal arch as a possible risk factor for ankle sprains: a prospective study in 83 female infantry recruits

Ability of a multi-segment foot model to measure kinematic differences in cavus, neutrally aligned, asymptomatic planus, and symptomatic planus foot types

BACKGROUND

Multi-segment foot models (MFMs) provide a better understanding of the intricate biomechanics of the foot, yet it is unclear if they accurately differentiate foot type function during locomotion.

RESEARCH QUESTION

We employed an MFM to detect subtle kinematic differences between foot types, including: pes cavus, neutrally aligned, and asymptomatic and symptomatic pes planus. The study investigates how variable the results of this MFM are and if it can detect kinematic differences between pathologic and non-pathologic foot types during the stance phase of gait.

METHODS

Independently, three raters instrumented three subjects on three days to assess variability. In a separate cohort, each foot type was statically quantified for ten subjects per group. Each subject walked while instrumented with a four-segment foot model to assess static alignment and foot motion during the stance phase of gait. Statistical analysis performed with a linear mixed effects regression.

RESULTS

Model variability was highest for between-day and lowest for between-rater, with all variability measures being within the true sample variance. Almost all static measures (radiographic, digital scan, and kinematic markers) differed significantly by foot type. Sagittal hindfoot to leg and forefoot to leg kinematics differed between foot types during late stance, as well as coronal hallux to forefoot range of motion. The MFM had low between-rater variability and may be suitable for multiple raters to apply to a single study sample without introducing significant error. The model, however, only detected a few dynamic differences, with the most dramatic being the hallux to forefoot coronal plane range of motion.

SIGNIFICANCE

Results only somewhat aligned with previous work. It remains unclear if the MFM is sensitive enough to accurately detect different motion between foot types (pathologic and non-pathologic). A more accurate method of tracking foot bone motion (e.g., biplane fluoroscopy) may be needed to address this question.

Differences in abductor hallucis activity during running in individuals with chronic ankle instability and copers

BACKGROUND

Assessment of neuromuscular dysfunction following a lateral ankle sprain during running typically focuses on the activities of the extrinsic foot muscles. Although the interaction between intrinsic and extrinsic foot muscles has been reported, there are no studies on the activities of intrinsic foot muscles in individuals with chronic ankle instability and ankle sprain copers.

RESEARCH QUESTION

Do copers and individuals with chronic ankle instability (CAI) have different abductor hallucis activity?

METHODS

This study included 11 controls, 11 copers, and 16 CAI participants. A wireless surface electromyography system was applied to the abductor hallucis, peroneus longus, tibialis anterior, and medial gastrocnemius muscles. Running was performed on a treadmill (speed of 3.5 m/s). The stance phase is divided into four functional phases. The muscle activities during these phases were calculated using the root mean square standardized by the root mean square during static standing with a double-leg stance.

RESULTS

Abductor hallucis activity was significantly lower during most phases in the coper and control groups than in the CAI group (P < 0.05). There were no differences in the extrinsic foot muscles among the groups (P > 0.05).

SIGNIFICANCE

Simultaneous investigations of muscle activity in the abductor hallucis and extrinsic foot muscles identified neuromuscular dysfunction after ankle sprains. Increased activity of the abductor hallucis may be associated with recurrent ankle sprains.

Activation Capacity of the Intrinsic Musculature of the Foot in Handball Athletes with Chronic Ankle Instability

Chronic ankle instability (CAI) is a common pathology in handball. The role of the intrinsic musculature of the foot in these players in relation to proprioception and stability has not been stablished. The objective of this study was to compare the ultrasound morphology of the heel fat pad of the foot in professional handball players to CAI in healthy players and establish relationships between CAI and physical and psychological variables. The study has been a descriptive observational case-control study in which 20 professional handball male players over 18 years of age were divided into 8 cases (CAI) and 12 controls (healthy). An ultrasound evaluation, the thickness and/or cross-sectional area at rest and the contraction measurement of the Abductor Digiti Minimi, Abductor Hallucis, Flexor Digitorum Brevis and Quadratus Plantae muscles were analyzed. Moreover, the compressibility index of the heel fat pad and the activation of the abdominal wall musculature (ultrasound), the flexion strength of the hallux and lesser toes (dynamometry), the foot functionality (Bristol Foot Score (BFS) questionnaire) and the psychological variables (self-reported questionnaires) were measured. There were no significant differences between the activation capacity values of the foot muscles of healthy and CAI athletes. Significant differences were found between groups regarding the BFS score (p = 0.007), d = 1.404), and significant correlations were also found between hallux flexion strength and lesser toes flexion strength in the total sample. Although there were no differences between the two groups, the identification of the activation pattern of these muscles in handball athletes is essential to the improvement of performance and preventing injuries such as CAI.

Ankle sprain and podoscopic footprint pattern in female volleyball players

Ankle sprain (AS) is the most common sports injury that can be complicated by chronic joint instability. The aim of this study was to examine the relationship between foot types and the ankle sprain events suffered during the sport career in female volleyball players. In this retrospective study, we randomly selected 98 female volleyball players competing in several divisions. Data were obtained from self-administered questionnaires in which the athlete noted data about volleyball practice, whether they had had ankle sprains and the number of these events. Plantar footprint was photographed by a plantoscope classifying each foot as normal, flat or cavus (196 feet). Of the 196 feet, 145 (74.0%) were normal, 8 (4.1%) were flat 43 and (21.9%) were cavus. Thirthy-five athletes reported at least one AS during volleyball practice. In total 65 sprain injuries were reported (35 to the right side and 30 to the left side). In 22 ankles (14 right, 8 left) sprain reinjure (AS >1) have been reported. A higher AS reinjury rate is correlated to the cavus footprint pattern (p = 0,005). Cavus foot associates to a higher risk of reinjury for ankle sprains in female volleyball players. Knowing the athletes which are more likely to sustain a reinjure may be helpful for the orthopedic surgeon to plan preventive strategies.

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.

The effects of calf muscles fatigue on dynamic plantar pressure distribution in normal foot posture and flexible flatfoot: A case-control study

BACKGROUND

Flexible flatfoot is associated with altered plantar pressure distribution, but it is not clear how muscle fatigue affects plantar pressure characteristics in flexible flatfoot and normal foot.

OBJECTIVE

To investigate the effects of calf muscles fatigue on plantar pressure variables in flexible flatfoot and normal foot.

METHODS

Twenty-five people with flexible flatfoot and twenty-five people with normal foot were included. The unilateral heel-rise test was used to induce calf muscles fatigue. Plantar pressure variables were collected during preferred walking immediately before and after fatigue. The two-way mixed-design ANOVA was used to determine the main effect of fatigue and the interaction between foot posture and fatigue.

RESULTS

Fatigue caused medialization of the contact area under the forefoot and the maximum force under the heel and forefoot (p< 0.05). When examining the differences in the effects of fatigue between groups, the contact area under the medial heel increased with fatigue in flexible flatfoot but decreased in normal foot; moreover, the contact area and maximum force under the midfoot and the maximum force under the third metatarsal decreased with fatigue in flexible flatfoot but increased in normal foot (p< 0.05).

CONCLUSIONS

Calf muscles fatigue caused medialization of the maximum force and contact area. Especially the midfoot was affected differently by fatigue in flexible flatfoot and normal foot.

Treatment Variability and Complications Associated With Pediatric Lateral Ankle Injuries: A POSNA Quality, Safety, and Value Initiative Survey

Background

Isolated pediatric lateral ankle injuries, including ankle sprain (AS) and nondisplaced Salter-Harris type 1 (SH-1) distal fibular fracture, are common orthopaedic sports-related injuries. Variability in treatment is suspected among pediatric orthopaedic surgeons. Complications from medical treatment or lack thereof have not been reported in this population.

Purpose

The purpose of this study was to investigate treatment variability and associated complications after pediatric AS and SH-1 via a survey of members of the Pediatric Orthopaedic Society of North American (POSNA).

Study Design

Cross-sectional study. Level of evidence, 5.

Methods

A voluntary, anonymous survey was distributed to POSNA membership (approximately 1400 members) via email. Survey questions, specific to both grade 1 or 2 AS and nondisplaced or minimally displaced SH-1 injuries in skeletally immature patients, focused on initial evaluation, immobilization, return to sports, and complications. We analyzed variability both in treatment between AS and SH-1 injury and in respondent characteristics. For statistical analysis, chi-square or Fisher exact test was used for categorical variables, and analysis of variance was used for continuous variables.

Results

The survey response rate was 16.4% (229/1400). Of the respondents, 27.7% used examination only to distinguish between AS and SH-1, whereas 18.7% performed serial radiography to aid with diagnosis. A controlled ankle motion boot or walking boot was the most common immobilization technique for both AS (46.3%) and SH-1 (55.6%); the second most common technique was bracing in AS (33.5%) and casting in SH-1 (34.7%). Approximately one-third of all respondents recommended either outpatient or home physical therapy for AS, whereas only 11.4% recommended physical therapy for SH-1 (P < .01). Results showed that 81.2% of respondents reported no complications for SH-1 treatment and 87.8% reported no complications for AS treatment. Cast complications were reported by 9.6% for SH-1 and 5.2% for AS. Rare SH-1 complications included distal fibular growth arrest, infection, nonunion, late fracture displacement, and recurrent fracture.

Conclusion

Significant variability was found in primary treatment of pediatric AS and SH-1 injuries. Rare complications from injury, treatment, and neglected treatment after SH-1 and AS were reported.

Measurement of the Developing Foot in Shod and Barefoot Paediatric Populations: A Narrative Review

The theory that footwear may change foot shape dates back 100 years. Since this period, research has revealed the anatomical and functional consequences that footwear can cause to the foot. Children’s feet remain malleable as they undergo developmental changes until adolescence, which is why childhood is arguably a crucial period to understand how footwear can affect natural foot development. This review explored the development of the foot in children and adolescents and the methods used to measure the different foot structures; it comments on the key issues with some of these methods and gives direction for future research. Various internal and external factors can affect foot development; the main factors are age, gender, ethnicity, body mass index (BMI) and footwear habits. Research on how footwear can affect foot development has increased over the years and the final section of this review aimed to unpick the findings. Studies investigating the influence of footwear habits on foot length and width have established inconsistent findings. Many of the studies in the review did not control for internal and external factors that can affect foot development. There was also a limited number of studies that investigated hallux valgus angle and muscle strength differences in those with different footwear habits. Moreover, multiple studies in the final section of this review did not successfully examine the footwear habits of the participants and instead used observations or self-assessments, which is a major limitation. Future research should examine footwear behaviors and other confounding factors when investigating the development of the foot in children and adolescents. Moreover, researchers should critically evaluate the methods used to quantify the different structures of the foot to ensure valid and reliable parameters are being used.

An association between excessive valgus hindfoot alignment and postural stability during single-leg standing in adolescent athletes

BACKGROUND

Diminished balance is associated with the incidence of ankle and lower extremity injuries in adolescents. Although flexible flatfoot is a common foot condition in pediatric and adolescent populations, the association between balance control and foot morphology remain unclear in adolescent athletes.

METHODS

Rearfoot angle in the double-limb standing position, body mass index (BMI), and isometric muscle strength related to the knee joint were retrospectively reviewed in 101 adolescent athletes (75 boys and 26 girls) with a mean age of 14.0 years (range 12-17). Postural stability during single-leg standing on static and dynamic platforms was investigated using Balance System SD in 119 feet without functional ankle instability. The participants were divided according to their rearfoot angle into control (less than 7°) and valgus (greater than or equal to 7°) groups. The measured parameters were compared between the control and valgus groups using Welch's t-test, and P values < 0.05 were considered statistically significant. Multiple regression analysis was conducted to identify the factors that significantly influenced postural control.

RESULTS

The average rearfoot angle was 4.6° in all participants. An excessive valgus rearfoot angle was detected in 53 feet (26.2%). No significant difference was found between the groups in terms of BMI and isometric knee muscle strength. Although no statistical differences were observed in postural stability on the static platform between the control and valgus groups, the valgus group demonstrated poorer postural stability for single-leg standing on the dynamic platform. Multiple regression analysis revealed that BMI and rearfoot angle were significantly associated with a poor postural control on the dynamic platform.

CONCLUSIONS

Our findings suggest that excessive rearfoot valgus specifically contributes to the deterioration of postural stability in adolescent athletes, and that rearfoot alignment should be evaluated for the adolescent population to prevent sports-related lower extremity injury.

Musculoskeletal Injuries Among Females in the Military: A Scoping Review

INTRODUCTION

Musculoskeletal injuries (MSKi) are a common challenge for those in military careers. Compared to their male peers, reports indicate that female military members and recruits are at greater risk of suffering MSKi during training and deployment. The objectives of this study were to identify the types and causes of MSKi among female military personnel and to explore the various risk factors associated with MSKi.

MATERIALS AND METHODS

A scoping review was conducted over a 4-month time frame of English language, peer-reviewed studies published from 1946 to 2019. Search strategies for major biomedical databases (e.g., MEDLINE; Embase Classic + Embase; and the following EBM Reviews-Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment, and the NHS Economic Evaluation Database) were developed by a senior medical information specialist and included 2,891 titles/abstracts. Study selection and data collection were designed according to the Population, Concept, and Context framework. Studies were included if the study population provided stratified data for females in a military context.

RESULTS

From a total of 2,287 citations captured from the literature searches, 168 peer-reviewed publications (144 unique studies) were eligible for inclusion. Studies were identified from across 10 countries and published between 1977 and 2019. Study designs were primarily prospective and retrospective cohorts. Most studies assessed both prevalence/incidence and risk factors for MSKi (62.50%), with few studies assessing cause (13.69%). For MSKi of female recruits compared to active female members, the prevalence was higher (19.7%-58.3% vs. 5.5%-56.6%), but the incidence (0.02%-57.7% vs. 13.5%-71.9%) was lower. The incidence of stress fractures was found to be much higher in female recruits than in active members (1.6%-23.9% vs. 2.7%). For anthropometric risk factors, increased body fat was a predictor of MSKi, but not stress fractures. For physiological risk factors for both female military groups, being less physically fit, later menarche, and having no/irregular menses were predictors of MSKi and stress fractures. For biomechanical risk factors, among female recruits, longer tibial length and femoral neck diameter increased the risk of stress fractures, and low foot arch increased risk of an ankle sprain. For female active military members, differences in shoulder rotation and bone strength were associated with risk of MSKi. For biological sex, being female compared to male was associated with an increased risk of MSKi, stress fractures, and general injuries. The consequences of experiencing MSKi for active military included limited duties, time off, and discharge. For recruits, these included missed training days, limited duty days, and release.

CONCLUSIONS

This scoping review provides insight into the current state of the evidence regarding the types and causes of MSKi, as well as the factors that influence MSKi among females in the military. Future research endeavors should focus on randomized controlled trials examining training paradigms to see if women are more susceptible. The data presented in the scoping review could potentially be used to develop training strategies to mitigate some of the identified barriers that negatively impact women from pursuing careers in the military.

The Design and Validation of a Low-Cost Foot Measurement System

It is estimated that approximately 40% of the population suffers from abnormal foot posture, specifically high arched or low arched feet. While the evaluation of foot posture can involve many aspects, it commonly requires the measurement of basic dimensions of the foot. Clinicians and researchers often rely on the use of specialized devices or three-dimensional (3D) scanners to evaluate specific aspects of a patient's foot posture. However, current technologies are extremely expensive, therefore highlighting the need for a cost-effective device to be used in rural and clinical settings. As a result, the purpose of this study was to develop an inexpensive system to measure total foot length, truncated length, dorsum height, navicular height, and foot width. Bland-Altman plots showed significant differences between this measurement system and a 3D scanner for total foot length, truncated length, and navicular height (p < 0.001) and significant differences when assessing the repeatability of dorsum height (p = 0.022). However, the magnitudes of these differences were minimal compared to the overall measurement. Additionally, interclass correlation coefficients revealed that this system had excellent validity when compared to a 3D scanner (interclass correlation coefficients = 0.908-0.994), and good to excellent repeatability when compared between days (interclass correlation coefficients = 0.867-0.996). These results demonstrate that it is possible to design an inexpensive, valid, and repeatable system that can be used in clinical, research, and rural settings to successfully evaluate basic dimensions of the foot that can be used for the determination of foot type.

Foot Posture and Plantar Loading With Ankle Bracing

CONTEXT

Arch height is one important aspect of foot posture. An estimated 20% of the population has pes planus and 20% has pes cavus. These abnormal foot postures can alter lower extremity kinematics and plantar loading and contribute to injury risk. Ankle bracing is commonly used in sport to prevent these injuries, but no researchers have examined the effects of ankle bracing on plantar loading.

OBJECTIVE

To evaluate the effects of ankle braces on plantar loading during athletic tasks.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 36 participants (11 men, 25 women; age = 23.1 ± 2.5 years, height = 1.72 ± 0.09 m, mass = 66.3 ± 14.7 kg) were recruited for this study.

INTERVENTION(S)

Participants completed walking, running, and cutting tasks in 3 bracing conditions: no brace, lace-up ankle-support brace, and semirigid brace.

MAIN OUTCOME MEASURE(S)

We analyzed the plantar-loading variables of contact area, maximum force, and force-time integral for 2 midfoot and 3 forefoot regions and assessed the displacement of the center of pressure. A 3 × 3 mixed-model repeated-measures analysis of variance was used to determine the effects of brace and foot type (α = .05).

RESULTS

Foot type affected force measures in the middle (P range = .003-.047) and the medial side of the foot (P range = .004-.04) in all tasks. Brace type affected contact area in the medial midfoot during walking (P = .005) and cutting (P = .01) tasks, maximum force in the medial and lateral midfoot during all tasks (P < .001), and force-time integral in the medial midfoot during all tasks (P < .001). Portions of the center-of-pressure displacement were affected by brace wear in both the medial-lateral and anterior-posterior directions (P range = .001-.049).

CONCLUSIONS

Ankle braces can be worn to redistribute plantar loading. Additional research should be done to evaluate their effectiveness in injury prevention.

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.

BIOMECHANICAL EFFECTS OF HYPERPRONATION ON MULTIDIRECTIONAL ANKLE ANGULAR DISPLACEMENT AND STIFFNESS

Hyperpronation of the foot is believed to contribute to ankle hypermobility and associated stiffness reduction, but the underlying biomechanical mechanisms remain unknown. This study aimsed to investigate multidirectional ankle displacement and associated stiffness when a posterior–anterior impact force was applied to the posterior knee compartment. Forty healthy adults with and without foot hyperpronation were recruited. A three-dimensional motion capture system and force plates were used to acquire angular displacement and ankle joint moment data. The independent [Formula: see text]-test and Mann–Whitney [Formula: see text] test were used to compare the group differences in ankle angular displacement, moment, and stiffness. Spearman’s rho test was performed to determine the relationship between ankle angular displacement and stiffness. The hyperpronation group demonstrated significantly greater sagittal ([Formula: see text]) and frontal plane ([Formula: see text]) angular displacements and reduced sagittal plane ankle stiffness ([Formula: see text]) than the neutral group. The Spearman’s correlation analysis showed a close inverse relationship between the ankle angular displacement and stiffness, ranging from [Formula: see text] to [Formula: see text]. The biomechanical data in our study suggest that individuals with foot hyperpronation present with multidirectional hypermobility and a reduction in ankle stiffness. These factors contribute to an increased risk of ankle-foot injury in individuals with foot hyperpronation.

Low Energy, Lateral Ankle Injuries in Pediatric and Adolescent Patients: A Systematic Review of Ankle Sprains and Nondisplaced Distal Fibula Fractures

BACKGROUND

Lateral ankle injuries are one of the most common musculoskeletal injuries sustained by pediatric and adolescent athletes. These injuries can result in significant time lost from competition, affect performance when returning to play, and represent a significant burden on the health care system as a whole. The purpose of this study was to systematically review the literature on the diagnosis, treatment, and prevention of acute lateral ankle injuries and their chronic effects in pediatric and adolescent athletes (younger than 19 y).

METHODS

This systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analysis) guidelines between September and December 2018. PubMed and Google Scholar were systematically searched using the search terms: ("distal fibula fracture" OR "ankle sprain") AND ("youth" OR "pediatric" OR "adolescent"). All authors participated in article review (N=172) for relevance and age restrictions in which 30 met the inclusion criteria.

RESULTS

Thirty articles met inclusion criteria [Levels of Evidence I to IV (I: n=4, II: n=16, III: n=9, and IV: n=1)] including distal fibula fracture diagnosis and treatment, and risk factors, prevention, and chronic sequela of lateral ankle injuries in pediatric and adolescent patients.

CONCLUSIONS

Low-energy, lateral ankle injuries are common in pediatric and adolescent patients, yet underrepresented in the medical literature. There is a lack of high-quality literature on diagnosis, treatment, and outcomes after Salter-Harris I distal fibula fractures. Available literature, however, suggests that there remains over diagnosis and over treatment of presumed Salter-Harris I distal fibula fractures. Adolescent ankle sprains dominate the available literature likely due to the high recurrence rate. Youth athletes and coaches should address risk factors and engage in injury prevention programs to prevent and minimize the effect of acute lateral ankle injuries.

LEVELS OF EVIDENCE

Level III-Systematic review.

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.

The effect of hydrodynamic insole on foot kinematics in individuals with flexible flatfoot: Case series using a single-subject design

The medial longitudinal arch of the foot is a dynamic structure while walking. The mobility of this structure in people with flexible flatfoot is partially or completely absent. The aim of this study was to investigate the efficacy of an insole that was designed to retrieve the medial longitudinal arch mobility in people with flatfoot. The study was a case series using a single-subject design. This single-subject design study was based on three subjects with flexible flatfoot. This study was designed in two phases: the baseline phase and the intervention phase. Each phase included five measurement sessions that were done in 5 consecutive weeks. We used the celeration-line method to detect the significant differences between the phases. Significant differences were recorded in the walking velocity, step length, and medial longitudinal arch mobility parameters when using the hydrodynamic insole. The results of this study showed that using the hydrodynamic insole may have a positive effect on the foot kinematics and gait parameters in people with flexible flatfoot.

Medial Longitudinal Arch: Accuracy, Reliability, and Correlation Between Navicular Drop Test and Footprint Parameters

OBJECTIVE

The purpose of this study was to evaluate the correlation among the navicular drop test, the arch angle, the Staheli index and the Chippaux-Smirak index. The reliability and the correlation among the footprint parameters were also estimated.

METHODS

A cross-sectional study (n = 86; 59.3% women; 27.8 years, standard deviation: 4.8 years) was carried out. The navicular drop test was evaluated and footprint parameters using a plantar pressure platform were recorded in the dominant foot. Pearson correlation coefficients, intraclass correlation coefficient, standard error of measurement, and minimum detectable change were calculated.

RESULTS

Both intrarater and interrater reliability were excellent for all the parameters evaluated (intraclass correlation coefficients > 0.880). Statistically significant correlations existed between the navicular drop test and footprints parameters (arch angle = 0,643; Staheli index = 0.633; Chippaux-Smirak index = 0.614). The footprint parameters had excellent correlation with each other (0.838-0.881). The navicular drop test and the footprint parameters studied were reproducible and thus had excellent reliability.

CONCLUSION

The correlations obtained between the navicular drop test and the footprint parameters evaluated were good. The navicular drop test appears to be a reproducible, valid, and simple test for evaluating medial longitudinal arch height, having fewer disadvantages than using footprint parameters.

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 running-induced fatigue on plantar pressure distribution in novice runners with different foot types

This study aimed to assess the effects of running-induced fatigue on plantar pressure parameters in novice runners with low and high medial longitudinal arch. Plantar pressure data from 42 novice runners (21 with high, and 21 with low arch) were collected before and after running-induced fatigue protocol during running at 3.3m/s along the Footscan(®) platform. Peak plantar pressure, peak force and force-time integral (impulse) were measured in ten anatomical zones. Relative time for foot roll-over phases and medio-lateral force ratio were calculated before and after the fatigue protocol. After the fatigue protocol, increases in the peak pressure under the first-third metatarsal zones and reduction under the fourth-fifth metatarsal regions were observed in the low arch individuals. In the high arch group, increases in peak pressure under the fourth-fifth metatarsal zones after the running-induced fatigue was observed. It could be concluded that running-induced fatigue had different effects on plantar pressure distribution pattern among novice runners with low and high medial longitudinal foot arch. These findings could provide some information related to several running injuries among individuals with different foot types.

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.

Height of the foot longitudinal arch and anterior cruciate ligament injuries

OBJECTIVE:

To evaluate the association between the height of the medial longitudinal arch of the foot and non-contact injuries of the anterior cruciate ligament.

METHODS:

One hundred and five patients were included in this case-control study. The case group consisted of 52 patients with non-contact injury of the anterior cruciate ligament. Fifty-three individuals with no history of symptoms regarding to feet or knees comprised the control group. An anthropometric assessment of the bony arch index was performed, which consisted of measuring the ratio of the height between the navicular bone to the ground and the distance from the most posterior support point of the calcaneus to the first metatarsal-phalangeal joint. Gender, height, weight, body mass index and the frequency of sports practice were also evaluated.

RESULTS:

Subjects in the case group had significantly higher medial longitudinal arches than individuals in the control group.

CONCLUSION:

Individuals with rupture of the anterior cruciate ligament had higher arches than the corresponding controls, suggesting an association between a high medial longitudinal arch of the foot and injury of the anterior cruciate ligament. Level of Evidence III, Case-Control Study

Foot posture as a risk factor for lower limb overuse injury: a systematic review and meta-analysis

Background

Static measures of foot posture are regularly used as part of a clinical examination to determine the need for foot level interventions. This is based on the premise that pronated and supinated foot postures may be risk factors for or associated with lower limb injury. This systematic review and meta-analysis investigates foot posture (measured statically) as a potential risk factor for lower limb overuse injuries.

Methods

A systematic search was performed using Medline, CINAHL, Embase, SportDiscus in April 2014, to identify prospective cohort studies that investigated foot posture and function as a risk factor for lower limb overuse injury. Eligible studies were classified based on the method of foot assessment: (i) static foot posture assessment; and/or (ii) dynamic foot function assessment. This review presents studies evaluating static foot posture. The methodological quality of included studies was evaluated by two independent reviewers, using an adapted version of the Epidemiological Appraisal Instrument (EAI). Where possible, effects were expressed as standardised mean differences (SMD) for continuous scaled data, and risk ratios (RR) for nominal scaled data. Meta-analysis was performed where injuries and outcomes were considered homogenous.

Results

Twenty-one studies were included (total n = 6,228; EAI 0.8 to 1.7 out of 2.0). There was strong evidence that a pronated foot posture was a risk factor for medial tibial stress syndrome (MTSS) development and very limited evidence that a pronated foot posture was a risk factor for patellofemoral pain development, although associated effect sizes were small (0.28 to 0.33). No relationship was identified between a pronated foot posture and any other evaluated pathology (i.e. foot/ankle injury, bone stress reactions and non-specific lower limb overuse injury).

Conclusion

This systematic review identified strong and very limited evidence of small effect that a pronated foot posture is a risk factor for MTSS and patellofemoral pain respectively. Evaluation of static foot posture should be included in a multifactorial assessment for both MTSS and patellofemoral pain, although only as a part of the potential injury risk profile. Whilst the included measures are clinically applicable, further studies are required to determine their relationship with dynamic foot function.

Electronic supplementary material

The online version of this article (doi:10.1186/s13047-014-0055-4) contains supplementary material, which is available to authorized users.

Associations of foot posture and function to lower extremity pain: results from a population-based foot study

OBJECTIVE

Studies have implicated foot posture and foot function as risk factors for lower extremity pain. Empirical population-based evidence for this assertion is lacking; therefore, the purpose of this study was to evaluate cross-sectional associations of foot posture and foot function to lower extremity joint pain in a population-based study of adults.

METHODS

Participants were members of the Framingham Foot Study. Lower extremity joint pain was determined by the response to the National Health and Nutrition Examination Survey-type question, "On most days do you have pain, aching or stiffness in your (hips, knees, ankles, or feet)?" The Modified Arch Index classified participants as having planus, rectus (referent), or cavus foot posture. The Center of Pressure Excursion Index classified participants as having overpronated, normal (referent), or oversupinated foot function. Crude and adjusted (age, sex, and body mass index) logistic regression determined associations of foot posture and function to lower extremity pain.

RESULTS

Participants with planus structure had higher odds of knee (odds ratio [OR] 1.57, 95% confidence interval [95% CI] 1.24-1.99) or ankle (OR 1.47, 95% CI 1.05-2.06) pain, whereas those with a cavus foot structure had increased odds of ankle pain only (OR 7.56, 95% CI 1.99-28.8) and pain at 1 lower extremity site (OR 1.37, 95% CI 1.04-1.80). Associations between foot function and lower extremity joint pain were not statistically significant except for a reduced risk of hip pain in those with an oversupinated foot function (OR 0.69, 95% CI 0.51-0.93).

CONCLUSION

These findings offer a link between foot posture and lower extremity pain, highlighting the need for longitudinal or intervention studies.

Association between foot type and lower extremity injuries: systematic literature review with meta-analysis

STUDY DESIGN

Systematic literature review with meta-analysis.

OBJECTIVES

To investigate the association between nonneutral foot types (high arch and flatfoot) and lower extremity and low back injuries, and to identify the most appropriate methods to use for foot classification.

METHODS

A search of 5 electronic databases (PubMed, Embase, CINAHL, SPORTDiscus, and ProQuest Dissertations and Theses), Google Scholar, and the reference lists of included studies was conducted to identify relevant articles. The review included comparative cross-sectional, case-control, and prospective studies that reported qualitative/quantitative associations between foot types and lower extremity and back injuries. Quality of the selected studies was evaluated, and data synthesis for the level of association between foot types and injuries was conducted. A random-effects model was used to pool odds ratio (OR) and standardized mean difference (SMD) results for meta-analysis.

RESULTS

Twenty-nine studies were included for meta-analysis. A significant association between nonneutral foot types and lower extremity injuries was determined (OR = 1.23; 95% confidence interval [CI]: 1.11, 1.37; P<.001). Foot posture index (OR = 2.58; 95% CI: 1.33, 5.02; P<.01) and visual/physical examination (OR = 1.17; 95% CI: 1.06, 1.28; P<.01) were 2 assessment methods using distinct foot-type categories that showed a significant association with lower extremity injuries. For foot-assessment methods using a continuous scale, measurements of lateral calcaneal pitch angle (SMD, 1.92; 95% CI: 1.44, 2.39; P<.00001), lateral talocalcaneal angle (SMD, 1.36; 95% CI: 0.93, 1.80; P<.00001), and navicular height (SMD, 0.34; 95% CI: 0.16, 0.52; P<.001) showed significant effect sizes in identifying high-arch foot, whereas the navicular drop test (SMD, 0.45; 95% CI: 0.03, 0.87; P<.05) and relaxed calcaneal stance position (SMD, 0.49; 95% CI: 0.01, 0.97; P<.05) displayed significant effect sizes in identifying flatfoot. Subgroup analyses revealed no significant associations for children with flatfoot, cross-sectional studies, or prospective studies on high arch.

CONCLUSIONS

High-arch and flatfoot foot types are associated with lower extremity injuries, but the strength of this relationship is low. Although the foot posture index and visual/physical examination showed significance, they are qualitative measures. Radiographic and navicular height measurements can delineate high-arch foot effectively, with only anthropometric measures accurately classifying flatfoot.

LEVEL OF EVIDENCE

Prognosis, level 2a.

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.

Foot structure and muscle reaction time to a simulated ankle sprain

CONTEXT

Foot structure has been shown to affect aspects of neuromuscular control, including postural stability and proprioception. However, despite an association between pronated and supinated foot structures and the incidence of lateral ankle sprains, no one to our knowledge has measured muscle reaction time to a simulated ankle-sprain mechanism in participants with different foot structures.

OBJECTIVE

To determine whether pronated or supinated foot structures contribute to neuromuscular deficits as measured by muscle reaction time to a simulated ankle-sprain mechanism.

DESIGN

Cross-sectional study.

SETTING

University biomechanics laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty volunteers were categorized into 3 groups according to navicular-drop-height measures. Ten participants (4 men, 6 women) had neutral feet (navicular-drop height = 5-9 mm), 10 participants (4 men, 6 women) had pronated feet (navicular-drop height ≥ 10 mm), and 10 participants (4 men, 6 women) had supinated feet (navicular-drop height ≤ 4 mm).

INTERVENTION(S)

Three perturbations on a standing tilt platform simulating the mechanics of an inversion and plantar-flexion ankle sprain.

MAIN OUTCOME MEASURE(S)

Muscle reaction time in milliseconds of the peroneus longus, tibialis anterior, and gluteus medius to the tilt-platform perturbation.

RESULTS

Participants with pronated or supinated foot structures had slower peroneus longus reaction times than participants with neutral feet (P = .01 and P = .04, respectively). We found no differences for the tibialis anterior or gluteus medius.

CONCLUSIONS

Foot structure influenced peroneus longus reaction time. Further research is required to establish the consequences of slower peroneal reaction times in pronated and supinated foot structures. Researchers investigating lower limb muscle reaction time should control for foot structure because it may influence results.

Foot pressure and center of pressure in athletes with ankle instability during lateral shuffling and running gait

This study evaluates foot pressure and center of pressure (COP) patterns in individuals with ankle instability during running and lateral shuffling. Eleven participants with ankle instability (AI) and 11 normal subjects (Normal) performed running and lateral shuffling tasks. The outcome measures were foot progression angle, peak pressure, and displacement of COP during stance phase. During running, the foot progression angle, that is, the angle of foot abduction, was lower in the AI group (Normal: 13.46° ± 4.45°; AI: 8.78° ± 3.91°), and the 1st metatarsal contact pressure (Normal: 0.76 ± 0.47 N/cm(2)·kg; AI: 1.05 ± 0.70 N/cm(2)·kg) and the 3rd metatarsal peak pressure were higher in the AI (Normal: 0.96 ± 0.60 N/cm(2)·kg; AI: 1.54 ± 0.68 N/cm(2)·kg). The medial-lateral (M-L) COP in the late-stance phase of running for the AI group transferred faster from lateral to medial foot than the Normal group. For lateral shuffling, the AI group had greater peak pressure at the 1st (Normal: 0.76 ± 0.67 N/cm(2)·kg; AI: 1.49 ± 1.04 N/cm(2)·kg), 2nd (Normal: 0.57 ± 0.39 N/cm(2)·kg; AI: 0.87 ± 0.68 N/cm(2)·kg), 3rd (Normal: 0.70 ± 0.54 N/cm(2)·kg; AI: 1.42 ± 0.87 N/cm(2)·kg), and 4th (Normal: 0.52 ± 0.38 N/cm(2)·kg; AI: 1.12 ± 0.78 N/cm(2)·kg) metatarsal areas than the Normal group. The M-L COP located more laterally from the early to mid-stance phase in the AI compared with the Normal group. The findings suggest that COP displacement during lateral shuffle may be a factor in ankle instability while the foot progression angle during running may be a compensatory strategy.

Prevention of physical training-related injuries recommendations for the military and other active populations based on expedited systematic reviews

BACKGROUND

The Military Training Task Force of the Defense Safety Oversight Council chartered a Joint Services Physical Training Injury Prevention Working Group to: (1) establish the evidence base for making recommendations to prevent injuries; (2) prioritize the recommendations for prevention programs and policies; and (3) substantiate the need for further research and evaluation on interventions and programs likely to reduce physical training-related injuries.

EVIDENCE ACQUISITION

A work group was formed to identify, evaluate, and assess the level of scientific evidence for various physical training-related injury prevention strategies through an expedited systematic review process. Of 40 physical training-related injury prevention strategies identified, education, leader support, and surveillance were determined to be essential elements of a successful injury prevention program and not independent interventions. As a result of the expedited systematic reviews, one more essential element (research) was added for a total of four. Six strategies were not reviewed. The remaining 31 interventions were categorized into three levels representing the strength of recommendation: (1) recommended; (2) not recommended; and (3) insufficient evidence to recommend or not recommend.

EVIDENCE SYNTHESIS

Education, leadership support, injury surveillance, and research were determined to be critical components of any successful injury prevention program. Six interventions (i.e., prevent overtraining, agility-like training, mouthguards, semirigid ankle braces, nutrient replacement, and synthetic socks) had strong enough evidence to become working group recommendations for implementation in the military services. Two interventions (i.e., back braces and pre-exercise administration of anti-inflammatory medication) were not recommended due to evidence of ineffectiveness or harm, 23 lacked sufficient scientific evidence to support recommendations for all military services at this time, and six were not evaluated.

CONCLUSIONS

Six interventions should be implemented in all four military services immediately to reduce physical training-related injuries. Two strategies should be discouraged by all leaders at all levels. Of particular note, 23 popular physical training-related injury prevention strategies need further scientific investigation, review, and group consensus before they can be recommended to the military services or similar civilian populations. The expedited systematic process of evaluating interventions enabled the working group to build consensus around those injury prevention strategies that had enough scientific evidence to support a recommendation.

Correlation between static foot type measurements and clinical assessments

BACKGROUND

An accurate and consistent differentiation of foot type is needed to assess appropriate treatments and to examine potential risk factors for acute and overuse injuries.

MATERIALS AND METHODS

One hundred forty-seven members of the American Orthopaedic Foot and Ankle Society were asked to complete a questionnaire related to clinical assessments of foot type and to examine 30 photographs of healthy feet taken on the mirrored foot photo box (MFPB). Responders were asked to categorize each image into one of five categories (pes planus, low arch, normal, high arch, and pes cavus). Different static measurements were obtained from each image. Pearson correlations were calculated between the static foot measures and the clinical grade. Significantly correlated parameters were analyzed via regression analysis.

RESULTS

Clinical assessment was reported to be the most important tool in defining foot type (69.9%) followed by standing radiographs and foot print measurements. Clinicians stated that arch height (56.2%) was the most used physical characteristic, while the lateral talo-first metatarsal angle (64.4%) was the most used radiographic assessment. Foot measurements were correlated with the clinical grade (r = 0.511 to 0.780). Regression analysis revealed that rearfoot angle, foot print index and truncated arch index were significant predictors of clinically defined foot type. Rearfoot angle accounted for 78% of the variance in clinically assessed foot type.

CONCLUSION

The results of this study indicate the need to measure multiple parameters to assess foot type. However, if only one parameter can be collected, it appears that rearfoot angle explains the majority of variance in the clinically assessed foot type.

Flat-footedness is not a disadvantage for athletic performance in children aged 11 to 15 years

OBJECTIVE

Because the controversy about the relation of foot morphology and foot function is still present, we find it surprising that there are no studies published dealing with motor skills and athletic performance in flat-footed school children. Our aim in this study was to determine if there is an association between the degree of foot flatness and several motor skills that are necessary for sport performance.

METHODS

The feet of 218 children aged 11 to 15 years were scanned, and the arch index was determined. The value of the arch index was corrected for the influence of age, and then the entire sample was categorized into 4 groups according to the flatness of their feet. The children were tested for eccentric-concentric contraction and hopping on a Kistler force platform, speed-coordination polygon (Newtest system), balance (3 tests), toe flexion (textile crunching), tiptoe standing angle, and repetitive leg movements. Altogether, 17 measures of athletic performance were measured.

RESULTS

No significant correlations between the arch height and 17 motor skills were found. Categorizing the sample into 4 groups did not reveal any differences between the groups in athletic performance. Also, several multivariate analysis of variance sets of multiple independent variables referring to a particular motor ability were not found to be significant. The differences were not found even after comparing only the 2 extreme groups, meaning children with very low and children with very high arches.

CONCLUSIONS

No disadvantages in sport performance originating from flat-footedness were confirmed. Children with flat and children with "normal" feet were equally successful at accomplishing all motor tests; thus, we suggest that there is no need for treatment of flexible flat feet with the sole purpose of improving athletic performance, as traditionally advised by many.

The effect of foot type on in-shoe plantar pressure during walking and running

The purpose of this study was to determine if low arch feet have altered plantar loading patterns when compared to normal feet during both walking and running. Fifty healthy subjects (34 normal feet, 16 flat feet) walked and ran five trials each at standard speeds. In-shoe pressure data were collected at 50 Hz. Contact area, peak pressure, maximum force, and force-time integral were analyzed in eight different regions of the foot. Foot type was determined by examining navicular height, arch angle, rearfoot angle, and a clinical score. A series of 2 x 2 repeated measures ANOVAs were used to determine statistical differences (alpha<0.05). A significant interaction existed between foot type and movement type for the maximum force in the medial midfoot. Total foot contact area, maximum force and peak pressure were significantly increased during running. Contact area in each insole area, except for the rearfoot, was significantly increased during running. Peak pressure and maximum force were significantly increased during running in each of the foot regions. However, the force-time integral was significantly decreased during running in the rearfoot, lateral midfoot, middle forefoot, and lateral forefoot. Significant differences between foot types existed for contact area in the medial midfoot and maximum force and peak pressure in the lateral forefoot. The maximum force and peak pressures were significantly decreased for the flat foot type. Therefore, individuals with a flat foot could be at a lower risk for lateral column metatarsal stress fractures, indicating that foot type should be assessed when determining an individual's risk for metatarsal stress fractures.

What is the best method for child longitudinal plantar arch assessment and when does arch maturation occur?

BACKGROUND

The medial longitudinal arch modifies significantly during growth. Nevertheless, authors differ on the age at which the foot acquires the adult-like shape. The best method to assess this arch in children is also controversial.

OBJECTIVES

Characterize the longitudinal arch of children between 3 and 10 years and compare the applicability of five evaluation methods.

METHODS

Plantar prints were acquired from 391 healthy preschools children from the University of Sao Paulo, Brazil. We calculated the arch indexes of: Cavanagh and Rodgers, Chipaux-Smirak, Staheli and the Alfa Angle, and compared them with the feet posture assessment. Non-parametric tests were used to compare among methods and ages. Spearman correlation was used to establish relationships among indexes.

RESULTS

3 and 4 years old showed a high prevalence of low arches (36-86%). Between 4 and 5 years old, significant difference was observed for all indexes. The indexes presented good correlation among them, although the proportions of the different arch types were different for each age group (p<0.001).

CONCLUSIONS

The longitudinal arch acquires an adult-like shape progressively, being statistically notorious the moment of medial longitudinal arch's formation between 4 and 5 years old. The Chipaux-Smirak Index is the best index to assess children's feet; it provides a better classification for lower arches and is easily calculated.

The relationship between the height of the medial longitudinal arch (MLA) and the ankle and knee injuries in professional runners

BACKGROUND

Usually the rate of lower extremity's injuries in sports such as running is known to be correlated with the height of foot arches. Foot pressure measurement studies have shown controversial results in this issue, mainly due to the complexity of the foot structure. This study aimed to investigate if any relationship exists between the MLA height and the ankle/knee injuries in professional runners. It was also aimed to find out any association between the foot pressure patterns and the clinical navicular drop test in the subjects.

MATERIALS AND METHODS

Forty-seven professional runners were participated in this study and using the clinical navicular drop test, they were categorized into normal, low and high arch foot subjects. Using an Emed pedography platform (Novel, Germany), the maximum force, peak pressure and the contact area of their feet were studied in both static (single limb support) and dynamic conditions.

RESULTS

The results of this study showed no strong correlation between the height of MLA and the rate of the ankle/knee injuries (P=0.58). The correlation between the clinical navicular drop test and the modified arch index (MAI) was between 0.32 in static and 0.57 in dynamic tests.

CONCLUSION

The results of this study conveyed that having a lower or higher than a normal MLA is not a definite risk factor for sports-related injuries. This might be due to the complexity of the foot structure and its ability to accommodate with new situations routinely occurs in sport. Furthermore, although a high correlation was not found between the clinical navicular drop test and the foot pressure indices, due to the clinical entity of this test, the obtained association is relatively good. A significant correlation was found between the foot pressure distribution in single limb support (static) and the dynamic conditions, which provides an extrapolation of the results of this type static condition tests to the dynamic conditions.

The correlation between selected measurements from footprint and radiograph of flatfoot

OBJECTIVES

To assess the subarch angle obtained from electronic footprints using a capacitive mat transducer system in children with flatfeet, to evaluate other foot arch indexes, and to compare the results with radiographic measurements.

DESIGN

A cross-sectional study.

SETTING

Rehabilitation clinic in a municipal hospital.

PARTICIPANTS

Thirty-two children (age range, 7-13y) diagnosed with flatfeet.

INTERVENTIONS

Radiographic measurements and foot shape measurements obtained from feet.

MAIN OUTCOME MEASURES

Talo-first metatarsal angle, talocalcaneal angle, talo-horizontal angle, and calcaneal angle were obtained from radiographs. Subarch angle, arch indexes, and long plantar angle were all captured and calculated via a capacitive transducer plate.

RESULTS

Correlations between the subarch angle and the talo-first metatarsal angle, talo-horizontal angle, and arch height were significant, as was the correlation between midfoot arch index and talo-horizontal angle. The forefoot arch index had no significant relationship with radiographic parameters. The talo-horizontal angle and arch height had significant relationships with the long plantar angle.

CONCLUSIONS

Measurement of the subarch angle had significant correlation with the radiographic parameters in children with flatfeet and it was accurately and easily obtained from a capacitive forceplate. Measurement of the subarch angle can be a useful tool in the assessment and diagnosis of flatfoot.