The Athletic Shoe in Football

Influence of playing surface on match injury risk in men's professional rugby union in England (2013-2019)

The use of artificial playing surfaces in professional rugby union is growing, but their effect on the injury risk profile remains unclear. The aim of this study was to examine the effect of playing surface on match injury risk in men's professional rugby in England. Six seasons of injury data (2013/14-2018/19) were collected from 15 professional English, men's rugby teams participating in domestic and European competition. The incidence, severity, and burden of match injuries were compared across playing surfaces. The dataset included 3351 injuries from a combined European and domestic data set (separated in to 2 categories; artificial and natural/hybrid surfaces) and 2675 injuries from a domestic only dataset (separated into 3 categories; artificial, hybrid, and natural surfaces). There were no differences in incidence rates between surface types on combined European and domestic match data, but injury burden was significantly greater on artificial (3082 days/1000 h, 95% CI 2847-3337) in comparison with natural/hybrid surfaces (2364 days/1000 h, 95% CI 2277-2454, p < 0.001). These differences were primarily driven by a significantly greater mean severity of hip/groin, and foot/toe injuries on artificial surfaces. This is the largest study to date to examine the relationship between surface type and injury risk in rugby union. The average severity and burden of injuries sustained on artificial surfaces was significantly greater compared with those sustained on hybrid/natural grass surfaces. This study can inform those involved in selection of surface for elite sport, weighing up the positive and negative elements of the varying surface types.

Validity and reliability study of the Turkish version of the 'A Sport Fitness Index'

BACKGROUND

The aim of this study was to adapt the 'Sport Fitness Index' into Turkish and to ensure its validity and reliability.

METHODS

After obtaining the necessary permissions, the Sports Fitness Index was independently translated from its English original to Turkish by four different physicians specialising in sports medicine. The content validity of index v.1 was calculated using the Davis technique in sample 1 of 20 people regularly participating in sports. In sample 2 consisting of 104 athletes who had a sports-related ligament/muscle injury or applied to the sports medicine clinic for general medical examination; the validity and reliability of index v.2 were examined. ROC analysis was applied to determine the cut-off point value of the score obtained from the Turkish version of the index.

RESULTS

The calculated I-CVI (lowest: 0.80, highest: 0.95) and S-CVI/Ave values (0.87) showed that the index provided content validity. Item 1 and item 10 were removed from the Turkish version of the index, as it caused a decrease in the Cronbach's alpha coefficient of the index v.2. Thus, the Cronbach's alpha coefficient of the index was calculated as 0.925. In the Turkish version of index v.2, the single-factor structure (explained variance rate 66.22%; eigenvalue 5.29) was preserved. The index provided confirmatory factor analysis model fit indices. The index provided a high level of negative correlation (r ˃ -.60; P = .0001) with the total score of the Physical Activity Inadequacy Scale Short Form-10 and the sub-scores of all summary components (r ˃ -.60; P = .0001). According to the ROC curve, the best cut-off point was 70 points with 96.6% sensitivity and 75% specificity in the Turkish version of the index.

CONCLUSION

The Sports Fitness Index-TR provided its Turkish validity and reliability with its 8-item and single-factor structure. The cut-off point is accepted as 70 points.

Epidemiology of Sports-Specific Foot and Ankle Injuries

The epidemiology of any given topic sometimes is overlooked. This is true particularly with sports physicians and sports injuries. The identification of sports-specific injury patterns by collection and examination of data can help prevent injuries. Thus, as a physician involved in any sport, it is essential to have this knowledge because understanding it and imparting it may allow a valuable contribution to the health and safety of the athletes and success of the teams.

A novel method for internal fixation of basal fifth metatarsal fracture in athletes: a cadaveric study of the F.E.R.I. technique (Fifth metatarsal, Extra-portal, Rigid, Innovative)

Purpose

One of the main problems of Kirschner wire fixation of fifth metatarsal base fractures (in combination with a tension band wiring technique) seems to be hardware intolerance and several studies in athletes also report failure after isolated fixation with a screw only. These reports prompted us to look at new materials and a novel technique through fixation with an intramedullary screw combined with a high-resistance suture via the presented F.E.R.I. (Fifth metatarsal, Extra-portal, Rigid, Innovative) technique.

Methods

This cadaveric study describes F.E.R.I. technique. On a cadaver, through two mini portals, a full reduction and solid internal fixation with an intramedullary screw and suture cerclage with Fiberwire of a fifth metatarsal base fracture is achieved. In this article, the cadaveric study and proposed surgical technique are explained and illustrated step by step.

Results

The presented internal fixation F.E.R.I. technique is indicated in acute proximal fractures, stress fractures or non-union of metatarsal 5 (Zone 2–3 by Lawrence and Botte) and it resulted feasible and stable during manual stress test. The authors intend to study this technique in the clinical setting in the near future.

Conclusions

Fifth metatarsal base fractures gain specific interest when occurring in athletes. In this group of patients, internal fixation is often required to obtain a satisfactory outcome and time to return to play. The aim of the presented cadaveric study is to illustrate an innovative concept of internal fixation, named F.E.R.I.

Higher Rates of Lower Extremity Injury on Synthetic Turf Compared With Natural Turf Among National Football League Athletes: Epidemiologic Confirmation of a Biomechanical Hypothesis

BACKGROUND

Biomechanical studies have shown that synthetic turf surfaces do not release cleats as readily as natural turf, and it has been hypothesized that concomitant increased loading on the foot contributes to the incidence of lower body injuries. This study evaluates this hypothesis from an epidemiologic perspective, examining whether the lower extremity injury rate in National Football League (NFL) games is greater on contemporary synthetic turfs as compared with natural surfaces.

HYPOTHESIS

Incidence of lower body injury is higher on synthetic turf than on natural turf among elite NFL athletes playing on modern-generation surfaces.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Lower extremity injuries reported during 2012-2016 regular season games were included, with all 32 NFL teams reporting injuries under mandated, consistent data collection guidelines. Poisson models were used to construct crude and adjusted incidence rate ratios (IRRs) to estimate the influence of surface type on lower body injury groupings (all lower extremity, knee, ankle/foot) for any injury reported as causing a player to miss football participation as well as injuries resulting in ≥8 days missed. A secondary analysis was performed on noncontact/surface contact injuries.

RESULTS

Play on synthetic turf resulted in a 16% increase in lower extremity injuries per play than that on natural turf (IRR, 1.16; 95% CI, 1.10-1.23). This association between synthetic turf and injury remained when injuries were restricted to those that resulted in ≥8 days missed, as well as when categorizations were narrowed to focus on distal injuries anatomically closer to the playing surface (knee, ankle/foot). The higher rate of injury on synthetic turf was notably stronger when injuries were restricted to noncontact/surface contact injuries (IRRs, 1.20-2.03; all statistically significant).

CONCLUSION

These results support the biomechanical mechanism hypothesized and add confidence to the conclusion that synthetic turf surfaces have a causal impact on lower extremity injury.

Treatment of Proximal Fifth Metatarsal Fractures and Refractures With Plantar Plating in Elite Athletes

BACKGROUND:

Fractures of the proximal fifth metatarsal are relatively common foot injuries in elite athletes. Acute fixation with intramedullary screws is the most common operative treatment. However, the rate of nonunion and refracture after this procedure remains a concern. The purpose of this study was to determine rates of clinical and radiographic fracture healing, return to sport, and patient-reported clinical outcomes of elite athletes with proximal fifth metatarsal fracture or refracture treated with plantar plating.

METHODS:

An institutional review board-approved retrospective single-surgeon case series investigation assessed athletes (competing at college, Olympic, or professional levels) with proximal fifth metatarsal fracture or refracture, treated with open reduction internal fixation and calcaneal autogenous bone grafting using a plantar plate with a minimum 2-year follow-up. Demographic data, radiographic evaluation, and the time until return to unrestricted sporting competition were collected and analyzed. Means with standard deviations were calculated for continuous data, and frequencies of categorical data were calculated in percentages.

RESULTS:

Four refractures and 4 primary fractures were treated in 8 male athletes with a mean age of 21.9 ± 1.9 years at a mean follow-up of 3.2 ± 0.4 years. Two patients experienced temporary neuropraxia of the sural nerve that resolved within 6 weeks. There were no incisional complications, delayed unions or nonunions, refractures, hardware loosening, or complaints of hardware prominence. Clinically asymptomatic radiographic union was observed in 100% of the athletes at 6.5 ± 1.1 weeks and full release given at 12.3 ± 1.9 weeks. All athletes returned to sport at the same level of competition.

CONCLUSION:

With minimum 2-year follow-up, plantar plating of proximal fifth metatarsal fractures was an effective and safe technique that was used in both primary and revision settings.

LEVEL OF EVIDENCE:

Level IV, case series.

Synthetic Turf: History, Design, Maintenance, and Athlete Safety

CONTEXT:

Synthetic turf has become an increasingly common playing surface for athletics and has changed dramatically since its introduction more than 50 years ago. Along with changes to surface design, maintenance needs and recommendations have become more standardized and attentive both to upkeep and player-level factors. In particular, synthetic turf maintenance as it relates to athlete health and safety is an important consideration at all levels of play.

EVIDENCE ACQUISITION:

A literature search of MEDLINE and PubMed for publications between the years 1990 and 2018 was conducted. Keywords included s ynthetic turf, artificial turf, field turf, and playing surface. Additionally, expert opinion through systematic interviews and practical implementation were obtained on synthetic turf design and maintenance practices in the National Football League.

STUDY DESIGN:

Clinical review.

LEVEL OF EVIDENCE:

Level 5.

RESULTS:

Synthetic turf has changed considerably since its inception. Playing surface is a critical component of the athletic environment, playing a role both in performance and in athlete safety. There are several important structural considerations of third-generation synthetic turf systems currently used in the United States that rely heavily on strong and consistent maintenance. A common misconception is that synthetic turf is maintenance free; in fact, however, these surfaces require routine maintenance. Whether athletes experience more injuries on synthetic over natural surfaces is also of interest among various levels and types of sport.

CONCLUSION:

Modern synthetic turf is far different than when originally introduced. It requires routine maintenance, even at the level of local athletics. It is important for sports medicine personnel to be familiar with playing surface issues as they are often treating athletes at the time of injury and should maintain a level of awareness of contemporary research and practices regarding the relationships between synthetic turf and injury.

Development of a Footwear Sizing System in the National Football League

Context:

Footwear performance and injury mitigation may be compromised if the footwear is not properly sized for an athlete. Additionally, poor fit may result in discomfort and foot injury such as fifth metatarsal stress fracture, foot deformities, turf toe, and blisters. Current footwear fitting methods consist of foot length and width measurements, which may not properly describe the shape of the individual foot, correlated with shoe size descriptors that are not standardized. Footwear manufacturers employ a range of sizing rubrics, which introduces shoe size and shape variability between and even within footwear companies. This article describes the synthesis of literature to inform the development and deployment of an objective footwear fitting system in the National Football League (NFL). The process may inform athletic footwear fitting at other levels of play and in other sports.

Evidence Acquisition:

Literature related to footwear fitting, sizing, and foot scanning from 1980 through 2017 was compiled using electronic databases. Reference lists of articles were examined for additional relevant studies. Sixty-five sources are included in this descriptive review.

Study Type:

Descriptive review.

Level of Evidence:

Level 5.

Results:

Current methods of footwear fitting and variability in the size and shape of athletic footwear complicate proper fitting of footwear to athletes. An objective measurement and recommendation system that can match the 3-dimensional shape of an athlete’s foot to the internal shape of available shoe models can provide important guidance for footwear selection. One such system has been deployed in the NFL.

Conclusion:

An objective footwear fitting system based on 3-dimensional shape matching of feet and shoes can facilitate the selection of footwear that properly fits an athlete’s foot.