February 2017

SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.

Issue link:

Contents of this Issue


Page 36 of 51 February 2017 | SportsTurf 37 football championships such as Ligue 1 in France agreed to ban artificial turf on pitch in 2017. ACL INJURY RISK FACTOR Acute traumatic ligament sprains injury at the ankle and the knee is frequently cited as a significant risk to athletes in sports that involve sudden stops and direction changes such as Ameri- can football, soccer or rugby. It represents a high proportion (up to 20%) of the total of the reported lower limb injuries. In particular, the very mediatized rupture of the anterior cruciate ligament (ACL) is known to be very incapacitating with at least a 4-months period away from the pitch. Even if the return to play rate after ACL reconstruction was very high, only two-thirds of the players competed at the highest-level 3 years later. ACL injury is usually multifactorial combining player's intrinsic and extrinsic factors, but it is interesting to highlight that for 85% of them it resulted from non-contact or indirect contact mechanism. In this case, 3 predominant playing situations have been identified leading to such trauma: (i) pressing following by re-gaining balance, (ii) re-gaining balance after kicking and (iii) landing after heading. These situations involve knee excessive valgus combined with internal rotation with the foot further away from the center of mass of the player. In addition, anterior cruciate ligament (ACL) injury is frequently cited as a significant risk to athletes on artificial turf mainly because of the changes in shoe- surface interaction. Thus, it could be interesting to compare the mechanical load- ing of knee joint during game situations performed on different surfaces with the assumption that higher knee inter-segmental load in valgus and internal rotation would lead to a higher risk of ACL injury. A study was design to compare the impact of three different surfaces and their potential role in the ACL injury risk. There is a paucity of on-field study assessing the impact of the soil on ground reaction forces under players' loading due to the difficulty of outdoor experimental design. To the other hand there is a huge need to go further to understand the underlying causes of injury on the different surfaces in the real-world context. So the first step was to adapt the experimental technique to the field environment. An experimental protocol was specially designed to analyze the influence of playing surface on force distri- butions during the landing phase of 3 movements, i.e. running, side-step cutting and jumping. To achieve this aim, motion analysis and ground reaction force of college rugby players were recorded during the same movement over the different surfaces. A greenhouse (Figure 1) with three different surfaces was built in order to control surface environment and moisture. Surface was divided in 3 (15 x 2 meters long) tracks made in accordance with ISO standards (NF P90-112 & NF P90-113). A natural grass track (NG) was composed of sand-based rootzone (Cargo-Green AG, Bassel, Switzerland), a third generation artificial turf track (AT) and a natural reinforced grass track (HY). The HY is composed of artificial rootzone of sand, cork and synthetic fibers in which natural lawn grows (AirFibr technology, Natural Grass, Paris, France). All tracks have been maintained following the same program. Then, players' ankle and knee joint strains related to the degree of impact absorption of the different surfaces were estimated by inverse dynamics taking into account body inertial parameters. FINDINGS Our results showed that speed and cadence of running were simi- lar among tracks contrary to the stress applied by the surface on players' joints. Indeed, knee joint loads were higher (+6 to 21%) on AT compared to natural ones, as well as ankle joint loads (up to 16-26%). Furthermore, valgus and internal rotation of knee joint during sidestep cutting were significantly higher on AT compared with the natural counterparts (+43% and 36% respec- tively). Since the ACL injury is mainly involved in combination of high levels of knee valgus and internal rotation strains, natural grass surfaces and especially the natural reinforced grass (HY, AirFibr technology) appeared to be safer for players. The main finding of this study is that playing surface has a sig- nificant effect on external knee moments during running, sidestep cutting and drop landing. As understanding the injury mechanisms is a key factor in injury prevention research, further investigations should focus on the development of detailed models of playing surface's mechanical behavior. To an injury point of view, it is obvious that a lot of attention should be paid to the choice of playing surface technology and it maintenance across the season. As the important aspect of sport surfaces is to improve player's athletic performance and safety, it is fundamental that club's technical, medical staff and groundsman communicate with each other to tackle the player's injuries issue. Dr. Philippe Rouch is Professeur des Universités, Directeur de l'Institut de Biomécanique Humaine Georges Charpak; Xavier Drevelle is with Service de Chirurgie Orthopédique – Hôpital Avicenne – Université PXIII; and Patricia Thoreux works for both institutions, all in Paris, France. (Figure 1) The greenhouse with three different surfaces

Articles in this issue

Links on this page

Archives of this issue

view archives of SportsTurf - February 2017