Sprint pattern analysis of professional female soccer players on artificial and natural turf (Análisis del patrón de carrera en jugadoras de fútbol femenino en césped artificial y natural)

Abstract. Introduction: There is few evidence that details the behavior of each spatiotemporal variable of the running pattern of female soccer players using different surfaces. Objective: To describe the spatiotemporal variables of the sprint pattern developed on natural and artificial turf by professional female soccer players. Methods: A cross-sectional study was conducted on nineteen (n=19) professional athletes with an average age of 22.3 years, who´s sprint spatiotemporal variables were evaluated in a natural (Bermuda 419) and artificial (Star 2) playing field through an optical measurement system (Opto Gait, Italy). The analysis of the differences of the space and time variables by turf was done with the Wilcoxon test for paired data and the differences in speed and acceleration by playing position was done using the Kruskal–Wallis test. The Spearman test was used to compare the correlation between speed, acceleration and anthropometric variables. Finally, an alpha level of 5% was considered for the whole analysis. Results: On the natural turf, the speed and cadence of the players were higher; on the artificial turf, the energy, flight time, contact phase and step angle were higher (p<0.05). On the other hand, an indirect relationship was observed between speed, contact time, percentage and fat weight (p=0.01). Conclusion: Our results suggest that the natural turf, Bermuda 419, allows for a faster sprinting patterns, characterized by lower energy use, flight time, contact phase and step angle. Resumen. Introducción: Existe poca evidencia que detalle el comportamiento de cada variable espaciotemporal del patrón de carrera de mujeres futbolistas utilizando diferentes superficies. Objetivo: describir las variables espacio temporales del patrón de carrera desarrollado en superficie natural y artificial por mujeres futbolistas profesionales. Métodos: se realizó un estudio de corte transversal en diecinueve (n=19) deportistas profesionales con un promedio de edad de 22.3 años, a quienes se les evaluaron las variables espacio temporales de la carrera en césped natural (Bermuda 419) y artificial (Star 2) a través de un sistema de medición óptico (Opto Gait). El análisis de las diferencias de las variables espacio temporales fue realizado con el test de Wilcoxon para datos pareados y las diferencias en la velocidad y aceleración fue realizados usando el test Kruskal-Wallis. El test de Spearman se usó para comparar la correlación entre las variables de velocidad, aceleración y antropométricas. Finalmente, un nivel de alpha de 5% fue considerado para el análisis total. Resultados: en la superficie natural, la velocidad y cadencia de las futbolistas fueron superiores; sobre superficie artificial, la energía, el tiempo de vuelo, la fase de contacto y el ángulo de paso fueron más altas (p<0.05). De otra parte, se observó una relación indirecta entre la velocidad, tiempo de contacto, porcentaje y peso graso (p=0.01). Conclusión: nuestros resultados sugieren que la superficie natural, Bermuda 419, permite un patrón de carrera más rápido, caracterizado por un menor uso de energía, tiempo de vuelo, fase de contacto y ángulo de paso.

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Análisis del patrón de carrera sobre superficie artificial y natural en futbolistas adolescentes (Analysis of the running pattern on artificial and natural surface in adolescent football players)

Retos ◽

10.47197/retos.v38i38.72337 ◽

2019 ◽

pp. 109-113

Author(s):

Brandon López-Gómez ◽

David Andrés Pérez-Mendoza ◽

Julián Santiago Guzmán-Revelo ◽

Luis Gabriel Rangel-Caballero ◽

Yully Corzo-Vargas ◽

...

Keyword(s):

Optical Measurement ◽

Cross Sectional Study ◽

Soccer Players ◽

Rank Test ◽

Paired Data ◽

Contact Phase ◽

Cross Sectional ◽

Natural Surface ◽

Running Pattern ◽

Support Phase

Introducción: Existe poca evidencia que detalle el comportamiento de cada variable espacio-temporal del patrón de carrera utilizando diferentes superficies. Objetivo: Comparar las variables espaciotemporales del patrón de carrera de futbolistas adolescentes en superficie natural y artificial. Método: se realizó un estudio de corte transversal con 18 jugadores de fútbol masculino (edad mediana= 12 años; Rango intercuartílico [RIC] 12-13). Mediante un sistema de medición óptico de 5 metros de longitud se analizó velocidad, aceleración, tiempo de contacto (Tc), tiempo de vuelo (Tv), fase de contacto, fase de apoyo, propulsión, zancada y cadencia. Las valoraciones fueron inicialmente desarrolladas en Superficie Artificial (SA) y 24 horas después en Superficie Natural (SN). Se utilizaron las pruebas Rangos con signos de Wilcoxon para datos pareados y el coeficiente de correlación de Spearman. Resultados: La SA mostró una fase de apoyo fue superior a la SN (SN: Me=0,05 RIC:0,03; 0,06; SA: Me=0,09 RIC 0,08;0,10; p <0,001). El Tv (SN: Me=0,16 RIC:0,14;0,19; SA: Me=0,04 RIC: 0,04;0,05; p<0,001), la fase de contacto (SN: Me=0,02 RIC:0,02;0,03; SA: Me=0,02 RIC: 0,01;0,02; p=0,040) y la propulsión (SN: Me=0,14 RIC:0,09;0,17; SA: Me=0,07 RIC:0,06;0,09; p=<0,001) fueron mayores en SN que en SA. Se encontró una relación indirecta entre velocidad y fase de contacto en SN. El Tv y la zancada se asociaron indirectamente con la aceleración en SA. Conclusión: el patrón de carrera varía según la superficie utilizada. La fase de contacto puede explicar la velocidad en la SN; mientras que el Tv y la zancada pueden explicar la aceleración en la SA.Abstract. Introduction: There is little evidence that details the behavior of each spatial-temporal variable of the running pattern using different surfaces. Objective: To compare the spatial-temporal variables of the running pattern over two surfaces in adolescent soccer players. Method: A cross-sectional study involving 18 male soccer players was conducted (median [Me] age = 12 years; Interquartile range [IQR] 12-13). Speed, acceleration, contact time (Ct), flight time (Ft), contact phase, support phase, propulsion, stride, and cadence were evaluated through a 5-meter long optical measurement system. The assessments were initially carried out on Artificial Surface (AS) and, 24 hours later, on Natural Surface (NS). The Wilcoxon signed-rank test for paired data and the Spearman correlation coefficient were used. Results: The support phase was greater in AS than NS (NS: Me = 0.05 IQR: 0.03; 0.06; AS: Me = 0.09 IQR 0.08; 0.10; p <0.001). The Ft (NS: Me = 0.16 IQR: 0.14; 0.19; AS: Me = 0.04 IQR: 0.04; 0.05; p <0.001), the contact phase (NS: Me = 0.02 IQR: 0.02; 0.03; AS: Me = 0.02 IQR: 0.01; 0.02; p = 0.040) and propulsion (NS: Me = 0.14 IQR: 0.09; 0.17; AS: Me = 0.07 IQR: 0.06; 0.09; p = <0.001) were greater in NS than AS. An indirect relationship between speed and contact phase in NS was found. The Ft and the stride were indirectly associated with acceleration in AS. Conclusion: The running pattern varies according to the surface used. The contact phase can explain the speed in the NS; while the Ft and the stride can explain the acceleration in AS.

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Maternal and Neonatal Evaluation of Derived Reactive Oxygen Metabolites and Biological Antioxidant Potential in Donkey Mares and Foals

Animals ◽

10.3390/ani11102885 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2885

Author(s):

Micaela Sgorbini ◽

Francesca Bonelli ◽

Giulia Percacini ◽

Anna Pasquini ◽

Alessandra Rota

Keyword(s):

Umbilical Cord ◽

Umbilical Artery ◽

Reactive Oxygen ◽

Wilcoxon Test ◽

Antioxidant Potential ◽

Gestation Length ◽

Reactive Oxygen Metabolites ◽

Paired Data ◽

Reactive Oxygen Metabolite ◽

Spearman Test

Our aim was to measure the concentrations of derived reactive oxygen metabolite (d-ROMs) and biological antioxidant potential (BAP) of donkey mares and foals at delivery and to verify the protective role of the placenta against fetal oxidative stress. A total of 15 Amiata jennies with a physiological gestation length and delivery were included together with 17 foals (two twin foalings). After delivery, maternal and foal venous blood samples were collected along with blood from the artery. Circulating lactate and plasma d-ROMs and BAP were evaluated. The Wilcoxon test for paired data was applied to verify differences in d-ROMs and BAP values, while the Spearman test was used to evaluate correlations. A significantly higher d-ROMs concentration was found in jennies compared to their foals, and to the umbilical artery blood. The BAP was higher in jennies than in their foals, but no differences were observed in the umbilical artery blood. No difference was found between foals and their umbilical cord. Blood lactate was higher in foals than in their dams. Positive correlations were found between mares and umbilical cord for BAP and d-ROMs, and between mares and foals and umbilical cord for BAP. In conclusion, the placenta may be a protective factor for the fetus. As with equine foals, the antioxidant system of donkey foals does not seems to be effective at birth.

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Effects of the Pitch Surface on Displacement of Youth Players During Soccer Match-Play

Journal of Human Kinetics ◽

10.2478/hukin-2018-0046 ◽

2018 ◽

Vol 65 (1) ◽

pp. 175-185

Author(s):

Ângelo Brito ◽

Paulo Roriz ◽

Pedro Silva ◽

Ricardo Duarte ◽

Júlio Garganta

Keyword(s):

Spatial Distribution ◽

Field Condition ◽

Body Height ◽

Soccer Players ◽

Movement Variability ◽

Artificial Turf ◽

Match Play ◽

Surface Conditions ◽

Distribution Maps ◽

Natural Turf

Abstract The aim of this study was to analyze the effect of different pitch surfaces (artificial turf, natural turf and dirt field) on positioning and displacement of young soccer players (age: 13.4 ± 0.5 yrs; body height: 161.82 ± 7.52 cm; body mass: 50.79 ± 7.22 kg and playing experience: 3.5 ± 1.4 yrs). Data were collected using GPS units which allowed to calculate spatial distribution variability, assessed by measuring entropy of individual distribution maps (ShannEn). Ellipsoidal areas (m2) representing players’ displacement on the pitch, centred on the average players’ positional coordinates, were also calculated, with axes corresponding to the standard deviations of the displacement in the longitudinal and lateral directions. Analysis of variance (ANOVA) was used to evaluate differences between pitch surfaces and across players’ positions. There was significant effect in positioning (η2 = 0.146; p < 0.001) and displacement (η2 = 0.063; p < 0.05) by the players between pitch surfaces. A dirt field condition induced an increase in the players’ movement variability, while players’ displacement was more restricted when playing on artificial turf. Also, there were significant effects on positioning (η2 = 0.496; p < 0.001) and displacement (η2 = 0.339; p < 0.001) across players’ positions. Central midfielders presented the greatest movement variability and displacement while fullbacks showed the lowest variability. Subsequently, the results may contribute to implement strategies that optimise players’ performance in different surface conditions.

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Relationship between the diameter of great saphenous vein and body mass index

Jornal Vascular Brasileiro ◽

10.1590/s1677-54492005000300008 ◽

2005 ◽

Vol 4 (3) ◽

pp. 265-269 ◽

Cited By ~ 4

Author(s):

Amélia C. Seidel ◽

Fausto Miranda Jr. ◽

Yara Juliano ◽

Neil F. Novo

Keyword(s):

Body Mass Index ◽

Body Mass ◽

Saphenous Vein ◽

The Body ◽

Lower Limbs ◽

Venous Disease ◽

Paired Data ◽

Color Flow ◽

Spearman Test ◽

Different Levels

OBJECTIVE: This study has been designed to correlate the diameter of the greater saphenous vein in different levels of the lower limbs with the body mass index of each individual to determine a possible relation between them. METHODS: Fifty-two lower limbs in 26 volunteers (six males and 20 females) without a chronic venous disease record, aged 21-68 were evaluated. Prior to color-flow duplex scanning the body mass index was defined. The deep and superficial venous systems and perforator veins were assessed as described in the literature. The diameter of the greater saphenous vein was measured with ultrasound longitudinal imaging in seven different levels. For the statistical analysis, Student t test for paired data and Spearman test were used. RESULTS: The difference observed in saphenous venous in the second and third levels when compared to the lower right and left limbs was not considered significant and a single group was formed to correlate with body mass index. The correlation was considered statistically irrelevant. CONCLUSION: By correlating the diameters of the greater saphenous vein with the body mass index of each individual it was noted that the relation between them is not significant, therefore it can be assumed that tall thin individuals can have greater saphenous vein with similar diameter as short fat individuals.

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Influence of Mechanical and Chemical Degradation in the Surface Roughness, Gloss, and Color of Microhybrid Composites

The Journal of Contemporary Dental Practice ◽

10.5005/jp-journals-10024-2032 ◽

2017 ◽

Vol 18 (4) ◽

pp. 283-288 ◽

Cited By ~ 5

Author(s):

Cleidiel AA Lemos ◽

Silvio J Mauro ◽

Paulo H dos Santos ◽

André LF Briso ◽

Ticiane C Fagundes

Keyword(s):

Surface Roughness ◽

Clinical Significance ◽

Composite Resin ◽

Color Change ◽

Wilcoxon Test ◽

Chemical Degradation ◽

Color Changes ◽

Final Data ◽

Properties Of Materials ◽

Spearman Test

ABSTRACT Aim The aim of this study was to investigate the association of different degradations on the roughness, gloss, and color changes of microhybrid composites. Materials and methods Ten specimens were prepared for Charisma, Amelogen Plus, Point 4, and Opallis resins. Surfaces were polished and baseline measurements of roughness, gloss, and color were recorded. Specimens were then submitted to chemical and mechanical challenges, and the specimens were reevaluated. Roughness and gloss were analyzed by Kruskal – Wallis and Dunn's test (p < 0.05). Color change (ΔE) was analyzed by one-way analysis of variance and Tukey's tests (p < 0.05). The initial and final data were compared using the Wilcoxon test (p < 0.05). Spearman test checked the correlation between the roughness and gloss (p < 0.05). Results Regarding surface roughness and gloss, there was no difference between composites before challenges. However, all composites showed a significant increase of roughness after challenges, with highest values for Charisma. The gloss was influenced by challenges, evidencing the best gloss for Point 4. Charisma showed the highest value of color change. There was no correlation between surface roughness and gloss for the initial analysis, and after the challenges. Conclusion Composites were influenced by association of challenges, and Charisma showed the highest changes for roughness, gloss, and color. Clinical significance The type of composite resin influenced the properties of materials, which are surface roughness, gloss, and color change. The dentist should be aware of the performance of different brands, to choose the correct required composite resin for each type of patient or region to be restored. How to cite this article Lemos CAA, Mauro SJ, dos Santos PH, Briso ALF, Fagundes TC. Influence of Mechanical and Chemical Degradation in the Surface Roughness, Gloss, and Color of Microhybrid Composites. J Contemp Dent Pract 2017;18(4):283-288.

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Abstract P263: Symptomatic Post-Acute SARS-CoV-2-Infection Hypertension Syndrome

Hypertension ◽

10.1161/hyp.78.suppl_1.p263 ◽

2021 ◽

Vol 78 (Suppl_1) ◽

Author(s):

Lauren East ◽

Zainab Mahmoud ◽

Amanda Verma

Keyword(s):

Blood Pressure ◽

Chest Pain ◽

Vital Signs ◽

Wilcoxon Test ◽

Initial Visit ◽

Office Visits ◽

Paired Data ◽

Cardiology Clinic ◽

Blood Pressures

Introduction: The Post-COVID Cardiology Clinic at Washington University evaluates and treats patients with ongoing cardiovascular symptoms following acute COVID-19 infection. One clinical manifestation seen in the clinic is an increase in blood pressure, with associated symptoms like chest pain. Our investigation aims to describe the increase in blood pressure seen in symptomatic patients presenting to the Post-COVID Cardiology Clinic. Methods: The study employed a retrospective cohort design of consecutive adult patients who presented between September 2020 to May 2021 with cardiovascular symptoms following COVID-19 infection. Demographic information, symptoms, vital signs, and follow-up visit data were collected for the patients. To determine a baseline blood pressure, two blood pressure readings from office visits prior to COVID-19 infection were averaged. The blood pressure values were compared between baseline and cardiology office visits using a non-parametric Wilcoxon test for paired data. Results: One-hundred patients were included in the cohort (mean age 46.4 years (SD 46.4); 81% (81) female). At the initial visit, there was a significant increase in systolic (median 128 mmHg) and diastolic (median 83.5 mmHg) blood pressure from baseline (systolic median 121.5, p=0.029; diastolic median 76, p<0.001). All patients with an increase in blood pressure reported symptoms like chest pain. In the subset of 36 (36%) patients that have followed up, 35 (97%) patients were prescribed a new anti-hypertensive or required an increased dose of a prior anti-hypertensive at their initial visit. Blood pressures at follow-up were not significantly different from baseline (median systolic delta= 1.0mmHg, diastolic delta= -1.0mmHg; p>0.05), and 83% (30) reported improvement in symptoms. Conclusions: Patients presenting with cardiovascular symptoms post-acute COVID-19 show increased blood pressure when compared to blood pressure prior to infection. During subsequent follow-up appointments, patients showed improvement in their blood pressure and symptoms. While the pathophysiology has yet to be determined, it is likely related to the effects of a proinflammatory state, endothelial dysfunction, dysautonomia, or altered effects of the RAAS.

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Matching legacy estimation of soil organic carbon changes from non-paired data with measured values in paired soil samples after two decades: a case study

10.5194/egusphere-egu21-10639 ◽

2021 ◽

Author(s):

Calogero Schillaci ◽

Sergio Saia ◽

Aldo Lipani ◽

Alessia Perego ◽

Claudio Zaccone ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Depth ◽

Soil Samples ◽

Wilcoxon Test ◽

Reliable Estimate ◽

Model Errors ◽

Paired Data ◽

Concentration Changes ◽

Legacy Data

Legacy data are frequently unique sources of data for the estimation of past soil properties. With the rising concerns about greenhouse gases (GHG) emission and soil degradation due to intensive agriculture and climate change effects, soil organic carbon (SOC) concentration might change heavily over time.When SOC changes is estimated with legacy data, the use of soil samples collected in different plots (i.e., non-aligned data) may lead to biased results. The sampling schemes adopted to capture SOC variation usually involve the resampling of the original sample using a so called paired-site approach.In the present work, a regional (Sicily, south of Italy) soil database, consisting of N=302 georeferenced soil samples from arable land collected in 1993 [1], was used to select coinciding sites to test a former temporal variation (1993-2008) obtained by a comparison of models built with data sampled in non-coinciding locations [2]. A specific sampling strategy was developed to spot SOC concentration changes from 1994 to 2017 in the same plots at the 0-30 cm soil depth and tested.To spot SOC changes the minimum number of samples needed to have a reliable estimate of SOC variation after 23 years has been estimated. By applying an effect size based methodology, 30 out of 302 sites were resampled in 2017 to achieve a power of 80%, and an a=0.05.After the collection of the 30 samples, SOC concentration in the newly collected samples was determined in lab using the same methodA Wilcoxon test applied to the variation of SOC from 1994 to 2017 suggested that there was not a statistical difference in SOC concentration after 23 years (Z = -0.556; 2-tailed asymptotic significance = 0.578). In particular, only 40% of resampled sites showed a higher (not always significant) SOC concentration than in 2017.This finding contrasts with a previous SOC concentration increase that was found in 2008 (75.8% increase when estimated as differences of 2 models built with non-aligned data) [2], when compared to 1994 observed data (Z = -9.119; 2-tailed asymptotic significance < 0.001).Such a result implies that the use of legacy data to estimate SOC concentration changes need soil resampling in the same locations to overcome the stochastic model errors. Further experiment is needed to identify the percentage of the sites to resample in order to align two legacy datasets in the same area.Bibliography[1]Schillaci C, et al.,2019. A simple pipeline for the assessment of legacy soil datasets: An example and test with soil organic carbon from a highly variable area. CATENA.[2]Schillaci C, et al., 2017. Spatio-temporal topsoil organic carbon mapping of a semi-arid Mediterranean region: The role of land use, soil texture, topographic indices and the influence of remote sensing data to modelling. Sci Total Environ.&#160;

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Sediment behaviour in grass filter strips

Water Science & Technology ◽

10.2166/wst.1999.0459 ◽

1999 ◽

Vol 39 (9) ◽

pp. 129-136 ◽

Cited By ~ 7

Author(s):

Ana Deletic

Keyword(s):

Overland Flow ◽

Complex Model ◽

Trapping Efficiency ◽

Artificial Turf ◽

Filter Strips ◽

Natural Grass ◽

Natural Turf ◽

Sediment Types ◽

Grass Filter Strips ◽

The Relationship

Sediment transport was studied in non-submerged overland flow over grass in a laboratory. Artificial turf (astro-turf) was used to simulate natural grass and no infiltration was allowed at this stage of the investigation. Experiments were conducted for different grass densities, flow rates, sediments inflows, and sediment types. It was observed that concentration of sediment in runoff decreases exponentially with the distance and reaches asymptotically a constant value. Measured sediment deposition was compered with the results calculated by the Kentucky model (tollner et al., 1976). The model over-predicted grossly the trapping efficiency of all particle fractions, but it is unreliable particularly for small particles. A new simplified relationship was established between particle fall number, Nf, and percentage of particles trapped in the grass. The relationship should be verified on natural grass before it is used in practice. Finally, infiltration of water and particles should be studied on natural turf, as well as, influence of grass blades bending, before the complex model of sediment behaviour in grass is established.

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Impact of daily versus weekly service of infectious diseases consultation on hospital antimicrobial consumption: a retrospective study

BMC Infectious Diseases ◽

10.1186/s12879-020-05550-1 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Andrea Cona ◽

Lidia Gazzola ◽

Ottavia Viganò ◽

Teresa Bini ◽

Giulia Carla Marchetti ◽

...

Keyword(s):

Infectious Diseases ◽

Hospital Setting ◽

Patient Characteristics ◽

Wilcoxon Test ◽

Defined Daily Dose ◽

Paired Data ◽

Comprehensive Management ◽

Time Period ◽

Infectious Diseases Consultation ◽

The Impact

Abstract Background To verify whether a daily service of Infectious Diseases consultation (ID-cons) is more effective than a weekly service in reducing antibiotic (ATB) consumption without worsening of clinical outcomes. Methods Two-year observational analysis of the ID-cons provided in a hospital setting in Milan, Italy. ID-cons resulted in: start-of-ATB; no-ATB; confirmation; modification-of-ATB. The impact of a weekly (September 1, 2016 - August 31, 2017 versus a daily (September 1, 2017 – September 30, 2018) service of ID-cons was evaluated in terms of: time-from-admission-to-first-ID-cons, type of ATB-intervention and number-of-ID-cons per 100 bed-days (bd). Primary outcomes: reduction of hospital ATB consumption overall and by department and classes expressed as Defined Daily Dose (DDD)/100bd (by Wilcoxon test for paired data). Secondary outcomes: overall and sepsis-related in-hospital annual mortality rates (as death/patient’s admissions). Results Overall 2552 ID-cons in 1111 patients (mean, 2.3 ID-cons per patient) were performed (18.6% weekly vs 81.4% daily). No differences in patient characteristics were observed. In the daily-service, compared to the weekly-service, patients were seen by the ID-consultant earlier (time-from-admission-to-ID-cons: 6 days (IQR 2–13) vs 10 days (IQR 6–19), p < 0.001) and ATB was more often started by the ID-consultant (Start-of-ATB: 11.6% vs 8%, p = 0.02), rather than treating physicians. After switching to daily-service, the number-of-ID-cons increased from 0.4/100bd to 1.5/100bd (p = 0.01), with the greatest increase in the emergency department (1.5/100bd vs 6.7/100bd, p < 0.001). Total ATB consumption decreased from 64 to 60 DDD/100bd. As for the number-of-cons, the consumption of ATB decreased mainly in the emergency area. According to ATB classes, glycopeptides consumption was reduced from 3.1 to 2.1 DDD/100bd (p = 0.02) while carbapenem use decreased from 3.7 to 3.1 DDD/100bd (p = 0.07). No changes in overall mortality (5.2% vs 5.2%) and sepsis-related mortality (19.3% vs 20.9%; p = 0.7) were observed among the two time-period. Conclusions Daily-ID-cons resulted in a more comprehensive management of the infected patient by the ID-consultant, especially in the emergency area where we also observed the highest rate of reduction of ATB-usage. No change in mortality was observed.

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Epidemiology of Anterior Cruciate Ligament Injury on Natural Grass Versus Artificial Turf in Soccer: 10-Year Data From the National Collegiate Athletic Association Injury Surveillance System

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120934434 ◽

2020 ◽

Vol 8 (7) ◽

pp. 232596712093443

Author(s):

Mark Howard ◽

Samantha Solaru ◽

Hyunwoo P. Kang ◽

Ioanna K. Bolia ◽

George F.R. Hatch ◽

...

Keyword(s):

National Collegiate Athletic Association ◽

Cruciate Ligament ◽

Injury Rate ◽

Acl Injury ◽

Soccer Players ◽

Artificial Turf ◽

Injury Surveillance System ◽

Injury Rates ◽

Natural Grass ◽

Anterior Cruciate

Background: Anterior cruciate ligament (ACL) injury is prevalent among National Collegiate Athletic Association (NCAA) soccer players. Controversy remains regarding the effect of the surface type on the rate of ACL injury in soccer players, considering differences in sex, type of athletic exposure, and level of competition. Hypothesis: Natural grass surfaces would be associated with decreased ACL injury rate in NCAA soccer players. Sex, type of athletic exposure (match vs practice), and level of competition (Division I-III) would affect the relationship between playing surface and ACL injury rates. Study Design: Cohort study; Level of evidence, 3. Methods: Using the NCAA Injury Surveillance System (ISS) database, we calculated the incidence rate of ACL injury in men and women from 2004-2005 through 2013-2014 seasons. The incidence was normalized against athletic exposure (AE). Additional data collected were sex, athletic activity at time of injury (match vs practice), and level of competition (NCAA division) to stratify the analysis. Statistical comparisons were made by calculating incidence rate ratios (IRR). Statistical significance was set at an alpha of .05. Results: There were 30,831,779 weighted AEs during the study period. The overall injury rate was 1.12 ACL injuries per 10,000 AEs (95% CI, 1.08-1.16). Women comprised 57% of the match data (10,261 games) and 55% of practice data (26,664 practices). The overall injury rate was significantly higher on natural grass (1.16/10,000 AEs; 95% CI, 1.12-1.20) compared with artificial turf (0.92/10,000 AEs [95% CI, 0.84-1.01]; IRR, 1.26 [95% CI, 1.14-1.38]) ( P < .0001). This relationship was demonstrated consistently across all subanalyses, including stratification by NCAA division and sex. The injury rate on natural grass (0.52/10,000 AEs; 95% CI, 1.11-1.26) was significantly greater than the injury incidence during practice on artificial turf (0.06/10,000 AEs; 95% CI, 0.043-0.096). Players were 8.67 times more likely to sustain an ACL injury during practice on natural grass compared with practice on artificial turf (95% CI, 5.43-12.13; P < .0001). No significant difference was found in injury rates between matches played on grass versus turf (IRR, 0.93; 95% CI, 0.84-1.03; P = .15). Conclusion: NCAA soccer players who practice on natural grass have increased risk of ACL injury compared with the risk of those practicing on an artificial surface, regardless of sex or NCAA division of play. No difference in risk of ACL injury between playing surfaces was detected during matches. Further research is necessary to examine the effect of multiple factors when evaluating the effect of the surface type on the risk of ACL injury in soccer players.

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