Natural turf, as the best covering for playgrounds, has been used for a long time. Natural structure and tissues have made it very sensitive to changes in weather and applied destructive forces and conditions during the athletic competitions. The destruction of turf layer results from different reasons usually accompanied with the extraction of plant roots from the soil or with soil compaction that decreases the field quality, specially during the compact competing seasons. The reinforcement of natural turf to enhance durability, is the best way to meet the requirements of playgrounds. In this study, to spread and absorb possible destructive forces the plastic or polymeric nets have been laid on the planting area during the seeding process to avoid soil compaction and expected damages to the turf roots. Test results have shown that using polymeric nets did not any negative effect on turf efficiency during the growing process. On the other hand, it can absorb p to 30% of destructive forces and blows in different directions. Walking test with a simulating walking machine has revealed a considerable increase in natural turf quality after reinforcement with polymeric nets.

Background: The effects of synthetic surfaces on the risk of injuries is still debated in literature and the majority of published data seems to be contradictory. For such reasons the understanding of injury incidence on such surfaces, especially in youth sport, is fundamental for injury prevention.Objectives: The aim of this study was to prospectively report the epidemiology of injuries in young football players, playing on Artificial turfs, during a one sports season.Patients and Methods: 80 young male football players (age 16.1±3.7 years; height 174±6.6 cm; weight 64.2±6.3 kg) were enrolled in a prospective cohort study. The participants were then divided in two groups; the first included players age ranging from 17 to 19 (OP) whereas the second included players age ranging from 13 to 16 (YP). Injury incidence was recorded prospectively, according to the consensus statement for soccer.Results: A total of 107 injuries (35 from the OP and 72 from the YP) were recorded during an exposure time of 83.760 hours (incidence 1.28/1000 per player hours); 22 during matches (incidence 2.84/1000 per player hours, 20.5%) and 85 during training (incidence 1.15/1000 per player hours, 79.5%). Thigh and groin were the most common injury locations (33.6% and 21.5%, respectively) while muscle injuries such as contractures and strains were the most common injury typologies (68.23%). No statistical differences between groups were displayed, except for the rate of severe injuries during matches, with the OP displaying slightly higher rates compared to the YP. Severe injuries accounted for 10.28% of the total injuries reported. The average time lost due to injuries was 14 days. Re-injuries accounted for 4.67% of all injuries sustained during the season.Conclusions: In professional youth soccer injury rates are reasonably low. Muscle injuries are the most common type of injuries while groin and thigh the most common locations. Artificial turf pitches don’t seem to contribute to injury incidence in young football players.

Background & Aim: Different surfaces have different effects on body mechanics during walking. The aim of this study was to evaluate ankle joint co-contraction in individuals with healthy and supinated feet during walking on Artificial turf and stable ground. Material & Methods: This study was a semi-experimental and laboratory one. The statistical population included 10 individuals with supinated feet (mean age of 22. 1± 2. 2 years) and 10 individuals with healthy feet (mean age of 24. 2± 3. 3 years). The electrical activity of selected lower limb muscles was recorded using electromyography system during walking. Two ways ANOVA with repeated measure test was used for statistical analysis using SPSS 20 software at significant level of 0. 05. Results: Results showed that the main effect of surface (P=0. 035) and group (P=0. 000) on general ankle co-contraction was significant during loading phase. General ankle co-contraction during loading phase while walking on Artificial turf was greater than walking on the ground. Differences between other directional and general co-contraction components in other phases during walking on Artificial turf and stable ground were not significant (P<0. 05). Conclusion: General co-contraction values of muscles during walking on Artificial turf were greater than walking on the stable ground. Increased general co-contraction may be associated with instability of the surface. Nevertheless, to prove this as well as possible, it is necessary to conduct more research in the future with larger statistical populations.

Background and Aim: Discoloration is among the most common problems of composite restorations. Color change over time compromises the main advantage of composite resins namely their high esthetics. In such cases, the restoration needs to be replaced. .The aim of this in-vitro study was to evaluate the effect of accelerated Artificial aging (AAA) on the color stability of three composite resins (Filtek Z250, Filtek Z250XT, and Filtek Supreme). Materials and Methods: In this experimental study, 7 composite specimens with equal dimensions were fabricated of each composite resin. The initial color of specimens was measured using a spectroradiometer according to the CIE L*a*b* system. The specimens were then submitted to AAA for 384h and underwent color assessment again. Before and after aging, the surface roughness of one specimen from each group was determined by Atomic Force Microscopy (AFM). The obtained color parameters were analyzed by one-way ANOVA and Tukey’s test. Results: The color change of Filtek Z250 was significantly lower than that of Filtek Z250XT and Filtek Supreme (P≤0.05). No statistically significant differences were found between Z250XT and Supreme in this respect (P>0.05 ). Conclusion: All composite resins showed color change above the clinically acceptable threshold. Z250 microhybrid composite was more color stable than nano-composites (Z250XT and Supreme). AAA increased the surface roughness in all groups but it was within the clinically acceptable range.

Background and Aims: More than 60 % of runners suffer from overuse injuries each year. Exercise and Running surfaces can prevent injuries and/or improve performance. The present study aims to investigate the effect of three types of running surfaces (Polyvinyl Chloride (PVC), Artificial turf, and sand) on the Ground Reaction Force (GRF) components in the stance phase of running. Methods: Impact force, loading rate, and free moment of 15 men were recorded while running barefoot on three PVC, Artificial turf, and sand surfaces at a speed of 3± 0. 2 m/s (Average of 5 correct attempts). Comparison between different conditions was performed using repeated measures ANOVA and Bonferroni’ s Post-Hoc Test. Results: The sand surface significantly reduced the impact force compared to the PVC and Artificial turf. Both sand and Artificial turf caused a significant reduction in the force loading rate compared to the PVC surface. The second peak of vertical GRF (propulsive force) increased at sand (P=0. 001) and Artificial turf (P=0. 005) surfaces compared to the PVC surface. Moreover, the sand surface reduced adductor torque compared to the PVC (p < 0. 001) and Artificial turf (P=0. 003) surfaces, while the Artificial turf reduced abductor torque compared to the PVC surface (P=0. 011). Conclusion: Sand is a safer surface for preventing running injuries due to eliminating impact force, reducing loading rate, and having high shock absorption. Training on a sand surface may improve performance on harder surfaces.

Introduction: Nowadays, the use of Artificial turf fields has become widespread. Given the high prevalence of noncontact injuries among female soccer players and high contribution of the Anterior Cruciate Ligament (ACL) injury, this research was conducted to compare biomechanical risk factors in the incidence of ACL injury for elite female soccer players during shearing maneuver and header on the natural grass and Artificial turf fields. Methods: Sixteen players were selected from U-14 women’, s national team by the convenience sampling method and started to perform the skills. Knee joint information was calculated by a 3D imaging system and a force plate. Statistical differences were reported using the dependent t-test at a significant level of 0. 05. Results: The findings showed that the biomechanical behavior of the lower extremity while performing soccer skills on the natural grass was affected differently from that on the Artificial turf. Results also demonstrated that the torque applied to the knee joint on the natural grass was higher than that on the Artificial turf (P=0. 039). Angular velocity on the Artificial turf was also higher than that on the natural grass (P=0. 006). Conclusion: The higher knee joint torque and the lower angular velocity on natural grass may result in a higher risk of ACL injury on the natural grass than on the Artificial turf. Therefore, the use of prevention programs for ACL injury is crucial to minimize the incidence of lower extremity injuries.