Document Type : Research Paper


1 Sports medicine department, Sport sciences research institute of Iran

2 Department of Physical education & Sport Sciences, Kharazmi University

3 Assistant Professor of Corrective Exercises and Sports Injuries, University of Tehran


The elastic properties and behavior of human body structure are potentially effective on perturbation control and force transmission and so could theoretically be considered as the determinant factors of musculoskeletal injury prevention. The purpose of this study was to determine the relationship between human body elastic behavior and musculoskeletal risk factors during unilateral landing. 30 young healthy men performed hopping and unilateral landing tests on a force plate and in front of a high-speed camera to quantify the elastic behavior and injury risk factors. Leg stiffness as one of the most important parameters of human body elastic behavior and time to stability, knee flexion and knee valgus as some injury risk factors were calculated and their relationships were determined by Pearson correlation test. There were some positive significant correlation coefficients between leg stiffness and initial and final knee flexion angle but there wasn't any relationship between leg stiffness and knee valgus parameters. Another important finding of this study was the positive significant correlation of leg stiffness and time to stability along with anteroposterior axis. According to the results, it seems although high values of leg stiffness is considered as an important factor to success in some movement performances like sprinting, actually it can disturb to adopt a correct landing technique and it can delay the anterior-posterior stabilization. Specific training method modifying the landing technique, regulating the leg stiffness and optimizing the body elastic behavior, can be effective on the prevention of lower body musculoskeletal injuries like ACL injury.