Amin Gandomkar - PHD Candidate of Sports Biomechanics, Faculty of Sport Sciences, Department of Sports Biomechanics and Physiology, University of Mazandaran, Babolsar, Iran.
Elham Gandomkar - M.CA of Sports Biomechanics, Faculty of Sport Sciences, Department of Sports Biomechanics and Physiology, University of Mazandaran, Babolsar, Iran.
Yaser Zahiri - M.CA students of Computer Engineering. Sobhan University, Neishaboor, Iran.
Javad Gandomkar - Bachelor of Science (BSc) in Engineering (Electro technique). Faculty of Technical and Engineering Faculty, Department of Electrical engineering, Mirdamad University, Gorgan, Iran.

Background & Objective: The purpose of current study was to investigate the compressive and shear mechanical forces of knee and ankle joints during running via modeling analysis. Material &Methods: 25 active healthy men (height 176.39±5.93 m, Mass 72.30±8.84 kg, Foot size 43.38±1.05) were asked to run with 3.5-4 m/s velocity in barefoot condition. Lower extremity was modelled via markers, then kinematic and kinetic parameters were recorded with synchronization of video camera (JVC, 250 Fps) and force plate systems (Kistler, 1000 Hz). Maximum compressive and shear forces of knee and ankle joints were calculated using inverse dynamics. Descriptive analysis and paired T-test were used to evaluate force loading pattern and compare mechanical forces magnitudes respectively (SPSS software, P<0.05). Result: Compressive and shear forces in knee began to increase after initial stance and reached to their peak amounts just before midstance. The ankle mechanical forces showed similar pattern, but reached to its peak in late stance before toe off. The peak compressive force was significantly greater by 78% in knee joint compared with ankle. However, ankle joint had greater shear force than the knee (P=0.01, 39%). Conclusion: The results revealed that the knee joint has a potential of injuries related to compressive tensions. However, in ankle joint, there is a potential of shear damages. In conclusion, protective tools and methods for knee joint including tape and knee straps is suggested for prevention of possible injuries during running

Mechanical joint Forces, Running, Kinematic, Kinetic