Biomechanical Model of Anterior Cruciate Ligament Injury Concerning Shin Angle and Field Surface Traction Parameters – with a Piezo2 Interpretation

Background: Biomechanical factors behind non-contact Anterior Cruciate Ligament (ACL) injury in soccer are still not fully understood. Unfortunately, ACL injuries almost always appear in game situations. Aim: To describe a possible ACL injury mechanism in male professional soccer players using MRI images and our own biomechanical model. Hypothesis: The friction parameters of the surface have extreme importance in the ACL injury mechanism. If the surface is more slippery, the horizontal component of the ground reaction force (GRF) will be smaller, consequently the torque originated from the GRF acting on the knee will be greater during the landing phase of a vertical jump, resulting in greater abduction effect on the knee. Consequently, the risk of knee injury increases. Methods: We have collected Magnetic Resonance Image images and anthropometric data of 15 healthy male individuals (age 19-23) to create a biomechanical model to calculate the torques in the knee to obtain more knowledge about ACL injury mechanism. Results: Lower extremity lean angle during the landing phase of a jump and friction parameters substantially affect abduction torques in the knee and consequently the risk of ACL injury occurrence. Conclusions: The landing posture when the knee is fully extended during landing is highly unfortunate for the ACL, compared to when the knee is partially flexed. If the knee is fully extended, greater hip abduction will increase the risk of an ACL injury, and if the surface is more slippery e.g. the surface is wet, the possibility of ACL injury is even greater. In addition, we also applied a molecular interpretation through acquired Piezo2 channelopathy, as the proposed preceding neuromuscular disruptor prior to non-contact ACL injury.