%0 Journal Article %T A Meta-Analysis of Soccer Injuries on Artificial Turf and Natural Grass %A Jay H. Williams %A Emmanuel Akogyrem %A Jeremy R. Williams %J Journal of Sports Medicine %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/380523 %X The goal of this investigation was to determine if playing or training on third-generation artificial turf (AT) surfaces increases the incidence rate of injuries compared to natural grass (NG) surfaces. This was accomplished by a meta-analysis performed on previously published research. Eight studies met the criteria of competitive soccer players, participation on both surfaces, and presentation of both exposure time and injury occurrence. Exposure time and injury incidence values were used to generate injury rate ratios (IRRs, AT/NG) for all injuries as well as specific injuries. Subgroup analyses were also performed by condition (match or training), gender, and age (youth or adult). The overall IRR was 0.86 ( ) suggesting a lower injury risk on AT than NG. However, there was considerable heterogeneity between studies. Analyses of individual injuries and subgroups found that in many cases IRR values were significantly less than 1.0. In no case was the IRR significantly greater than 1.0. Based on this, it appears that the risk of sustaining an injury on AT under some conditions might be lowered compared to NG. However, until more is known about how issues such as altered playing styles affect injury incidence, it is difficult to make firm conclusions regarding the influence of AT on player safety. 1. Introduction Unfortunately, acute injuries are far too common in the sport of soccer. Sprains and ruptures of the ligaments supporting the ankle and knee joints as well as muscle strains occur quite often. In some cases, joint injuries are sustained through contact with another player. A classic example occurs when one player collides with another, applying excessive force to the lateral side of the opponent¡¯s knee. This often results in damage to the medial collateral ligament, lateral meniscus, and the anterior cruciate ligament (ACL). However, a substantial number of soccer injuries occur through noncontact mechanisms. In these cases, an athlete may plant his or her foot then stop, cut, or turn. As the body changes direction while the foot is stationary, the knee and/or ankle experiences torque. As a result, ligament structures can be strained or ruptured. Researchers have identified a number of risk factors for noncontact injuries. These include intrinsic factors such as proprioception, muscular strength, ligament properties, and biomechanics as well as extrinsic factors such as the playing surface and other environmental conditions. Several studies have focused on this latter factor as important, specifically the use of artificial turf playing %U http://www.hindawi.com/journals/jsm/2013/380523/