Transmissibility of swing and vertical vibrations in human lower limb

Abstract

目的: 研究在膝关节锁定、膝关节固定角度以及膝关节自然状态的站立条件下相同振动频率不同形式的振动在人体下肢内的传递情况。 方法: 以摇摆振动和垂直振动作为激励施加与受试者足底,进行三种站立条件下人体跟骨、外踝、胫骨外髁以及股骨外侧髁等处的振动测试,并运用转子动力学全相位能量补偿法进行人体下肢的振动传递分析,得到了摇摆振动和垂直振动过程中,三种不同的站立条件下人体跟骨、外踝、胫骨外髁以及股骨外侧髁等处的振动传递及振动加速度的分布。 结果: 在相同频率条件下,与摇摆振动激励方式相比,垂直振动激励下人体下肢标记点加速度明显减小,振动传递比较大;对同一个受试者垂,直振动在人体下肢的传递要比摇摆振动的传递稳定。此结果对于深入了解全身振动对人体骨骼及肌肉的锻炼及骨科疾病的防护有一定的借鉴作用。 Objective: To investigate the transmissibility of the swing and the vertical vibration in human lower limb with three postures, eg. the knee lock ,knee angle loek and knee normal conditions. Methods: The swing and vertical vibrations were added on the subject’s foot segments and then the points on the calcaneus, lateral malleolus, tibial lateral condyle and fumer lateral condyle were monitored when the subjerts were with 3 postures. The phase difference correcting Methods of discrete spectrum which were widely used in rotor dynamics analysis were applied in the transmissibility analysis. The transmissibility and energy distribution of marked points on the lower limb with three postures during swing and vertical vibrating process were obtained. Results: It was indicated that the vertical vibration accelerations of marked points in the subject’s lower limbs were greater with same postures than those of swing vibration. And the transmissibility ratios of those marked point of vertical vibration were a litter greater than those of swing vibration. Also the vertical vibration transmissibility was steadier than the swings’.