| Summary: | 碩士 === 國立成功大學 === 醫學工程研究所 === 87 === Slip is the frequently accident in our daily life. And this accident makes more hurt because of losing balance of human body. The light bring about tissue hurt, for instance: ankle sprain, ligament of knee sprain… etc. The heavy probably makes the death happen. In order to avoid this hurt happened in our environments, so we must study out this problem for finding out the key point of human slipping. In the past, many scholars do the work in friction coefficient (). The influence factor of human slipping is not only the which relationship of foot and ground but also the sides of biomechanics, neurophysiology, musculoskeletal system.
In this study, twenty two health subjects, divided into two groups of twelve and ten subjects each (12 male, 10 female), will be subjected to slip disturbance. All subjects walked in the walkway and were divided into two different interfaces of group and two cadences (120 steps/min, 90 steps/min). In the same time, the data of kinetics and kinematics collection of subjects by motion analysis system and force plate system. The subjects wearing a body safety harness, which is tethered by two ropes to support the structures in a way that full falls and will be smoothly arrested before contact.
The result of study found, there will be three period ( speed down period, stable period, speed up period) after heel strike. And the key point of slip will be decided in two period of speed down and stable. The velocity of heel will be slow down to near zero value in normal level walking, and the velocity of heel in the group (slip & fall) will be a peak value which higher velocity of heel. In the factor of cadence, the faster cadence makes subject fall easier when the step length controlled. In the motion of joint of lower extremity, we can see that hip and knee joint will keep in a flexion angle to descend the center of body in slippery interface and the ankle joint will make more plantarflexion angle for increasing the contact surface between foot and ground. In the moment of joint, extension moment of hip, knee joint and dorsiflexion moment of ankle joint is important influence on balance recovering when subjects were in perturbation gait.
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