The Experimental Study And Apply Of Relationship Between Main Joint Torque And End Effector Force Of Lower Limbs

The research tests three-dimensional force and torque of terminal effectors of lower limbs among 24 objectives in three different groups by using lower limbs surveying instrument. By regulating the angle between pedal and distance, the distance between pedal and chair, we tested the force and torque of terminal effectors in different angles of joint and analyzed these date by relative software and calculated the angel torque of joint for hip, knee and ankle according to Vladimir M. Zatsiorskys'theory. Progressively, we validated the theory of Vladimir M. Zatsiorsky and acquired the rate of increase about lower limbs'joint torque (coxa, knee and ankle). Basing upon it, we can acquire the rate of increase of lower limbs'joint torque (coxa, knee and ankle) under different conditions of joint angel and force elicited from terminal effectors. Therefore, we can judge the limiting joints providing instructions for sports training and diagnoses for skills. The thesis can be concluded:(1)The research devised the system of lower limbs surveying instrument by us. We can test the force and torque elicited by terminal effectors on different joints configuration and calculated the main joints'force and movement of lower limbs. The system suits to the event as cycling﹑ canoeing/kayaking﹑weight-lifting and running etc.(2)According to the results, we can know that the optimal joint configuration could elicit the largest force for individual and it is unbalance on the lower limbs of left and right.(3)Analyzing the results, we draw a conclusion: under the same condition, the largest force and torque tested from terminal effectors of lower limbs is weaker for female than that for male and the joints'torque is also the same case. For every subject, at the same joint angle, the force is the largest, but the torque of every joint is not the same. That is the joint angle should be different on two conditions that the torque of lower limbs is largest and the force elicited from muscle is largest.(4)Tested the force and torque of lower limbs joint, we validated the theory of Vladimir M. Zatsiorskys (theory of virtual work and inference. The inference is when a subject exerts a static force on the environment and the body posture and force directions do not change, the torques in the involved joints is defined uniquely, any increase in the endpoint force requires a simultaneous, proportional increase in all the joint torques). We can also conclude that the increase rate of lower limbs'torque is identical at the different joint angles to every subject. The rate is 6:3:1 for joint of hip, knee and ankle in our research and the rate should not change together with gender and fatigue of subjects.