Brito et al. (2010) studied isokinetic knee strength ratio in sub-elite male soccer players, and their results showed that the ratio in the non-dominant leg is more than that in the dominant leg. They found that hamstrings�� peak torque of the non-dominant leg is stronger than in those of the dominant leg (Brito et al., 2010). The conventional inhibitor Pazopanib strength ratio is calculated as peak torque of hamstrings divided by that of quadriceps muscles. Increasing flexor PT improves the knee strength ratio at this angular velocity. These conflicting results may be caused by the differences in the level of play of the subjects. Professional soccer players have higher quadriceps strength than non-professional players (Gil et al., 2010). The results of the present study showed the CSR (normal average; 0.

61, 0.72, 0.78 at 60��/s, 180��/s and 300��/s, respectively) and DCR (normal average>1.0) of the players were below the normal average values at various angular speeds which predispose the players to knee injuries. Kim and Hong (2011) studied the National College American Association (NCAA) athletes and found an association of lower than 0.6 of the CSR at 60��/s and non-contact leg injuries, suggesting the significant contribution of hamstring to quadriceps imbalance to non-contact leg injuries. Fousekis et al. (2011) measured intrinsic risk factors during pre-season in 100 professional soccer players and found players with eccentric hamstring strength asymmetries were at greater risk of hamstring strain while players with eccentric strength and flexibility asymmetries in their quadriceps were at greater risk of quadriceps strain.

The anterior cruciate ligament (ACL) and hamstring become more susceptible to injury with a mismatch of hamstring to the quadriceps strength ratio. This is because the strength of hamstring is protective against anterior translation of the tibia on femur which occurs during landings and sudden changes in direction. A lower hamstring to quadriceps strength ratio allows higher shear forces on the ACL during these activities. Furthermore, hamstrings strain which commonly follows eccentric lengthening during the terminal swing can be attenuated by increasing the hamstrings strength (Holcomb et al., 2007). In this study we found that the hip flexibility in the dominant leg was significantly higher than that in the non-dominant leg.

The dominant GSK-3 leg is used to handle an object or to lead out, while the non-dominant leg has the main role of providing postural support. This definition of footedness is commonly accepted by researchers (Hardt et al., 2009). Soccer players use one favoured foot unilaterally for kicking the ball (Rahnama et al., 2005; Fousekis et al., 2010). This preference is a possible cause of an asymmetry in flexibility. Professional soccer players can perform a higher Dynamic Range of Motion of the hip joint during an instep kick after dynamic stretching (Amiri-Khorasani et al., 2011).