مکانیک اندام تحتانی حین هاپینگ روی سطوح با سفتی های مختلف

Abstract

Fifteen young and healthy males volunteered for this Quasi-experimental study. Kinematic and kinetic data were recorded during hopping on hard spring surfaces (300-500kN/m) and force plate using the Motion Analysis System and AMTI force plate. In the data analysis process, leg and joint stiffness, maximum Vertical Ground Reaction Force, and mechanical energy expenditure were calculated. The results showed that Leg stiffness and VGRF, ankle joint angle and stiffness, and ankle joint MEE were higher during hopping on the force plate (P<0.05), and hip joint stiffness and MEE were higher on the spring surface (P<0.05). The results of multiple regression revealed that the ankle joint is the main regulator in the force plate and the hip joint is the main regulator in the spring surface. In conclusion, during hopping on the hard spring surface, the joint regulator is shifted from the ankle to the hip joint, to help the person use a softer but more efficient motion. Therefore it seems that the strategy selected for motion on the hard spring surface is performing motion with a lower risk of injury and lower energy cost.