Comparison between changes Vertical Ground Reaction Force and center of pressure among the Athlete male with genu varum and healthy subjects during landing tasks

Poster Presentation
Paper ID : 1378-12THCONG
Oral / Poster Presentation File: Slide1.JPG 
1Ph.D student of Sport Biomechanics in Islamic Azad University, Central Tehran Branch, Tehran, Iran
2Full Professor, Sport Biomechanics and Injury Department, Faculty of Physical Education and Sport Sciences, Kharazmi University, Tehran, Iran
3M.A in Sport Biomechanics, Islamic Azad University, Central Tehran Branch, Tehran, Iran
Changes in biomechanical variables during jump and landing exercise activities are important for improving athletes, performance levels and reducing the risk of sports injuries. The present study compares the vertical component of ground reaction force and displacement of center of pressure fluctuations between athlete's genu varum knee and healthy athletes during single leg landing.
20 healthy men and 20 male with genu varum volunteered to participate in this study. First, the subject was placed on a platform 30 cm high, standing on two legs with his hands on his hip. Then, the subject descended to the center of the force plate with a superior leg over the platform whose front edge was 15 cm away. A Kistler force plate (1000 Hz) was used to measure of GRFs components and changes center of pressure during landing. Then, peak and downfall values of GRFs, loading rate, along with time to peak were extracted. Paired t test with significance level was used for statistical analysis (P≤0.05).
The results showed that the subjects with genu varum knee had less reaction force (Fz1,2,3) on landing as compared to healthy subjects (P<0.05) and also the displacement in center of pressure in internal-external direction was significantly different (P<0.021).
People with genu varum knee experience lower loads due to the low reaction forces, but external rotation of the knee changes the biomechanics of the lower limbs and increases the risk of injury. Pressure center changes can also be considered as a risk factor for increased fracture stress in soft tissue and ligament injury, especially damage to the anterior cruciate ligament due to poor imbalance.