正着走与退着走生物力学机制研究

Biomechanical Mechanism about Forward and Backward Walking

目的:揭示退着走的相关生物力学机制,为推广退着走健身模式提供重要的生物力学依据。方法:通过运动学、动力学、肌电等手段同步测试相关生物力学参数,并运用逆动力学计算获得步行中髋、膝、踝关节力矩和关节功。结果:与正着走相比,退着走受试者受走向的影响较大,因此退着走在步速、步频、跨步长等方面显著变短,单步时间、双支撑时间、第1双支撑时间则显著变长,而2种走模式下的相关关节角位移表现惊人的相似性;正着走时,踝关节力矩模式与时相反转后退着走亦表现惊人的相似,而膝、髋2关节却没有如此雷同;2种走模式下的踝、膝、髋关节功率差异明显,并推断退着走的主要推动力及震荡吸收来自踝关节,膝、髋2关节几乎不能产生推动功率;正着走时,受监测的大腿肌肉中,除股直肌肌电活动低于退着走外,股二头肌、股内肌及股外肌活动显著高于退着走;4块小腿肌中,退着走时,腓肠肌内侧、腓肠肌外侧、胫骨前肌及比目鱼肌的肌电活动均显著高于正着走,进一步左证退着走的动力源来自踝关节,而正着走,其动力源主要由髋与膝关节承担。结论:退着走练习可修改神经机制而有助于运动学习,这对受损的肌肉骨骼功能再教育是有益的;退着走髌骨-股骨关节承受来自地面的反应力要低,因此,退着走对下肢过度使用受伤的病人康复是有益的。

Objective： This study expects to reveal the relevant biomechanical mechanism of backward walking （BW） in order to provide the biomechanical basis for popularizing fitness model of BW. Methods ： The kinematics, dynamics, EMG means have been used synchronously to obtain biomechanical parameters, and the hip, knee, ankle and foot joint torque and joint function were gained by inverse dynamics. Results： Compared with forward walking （FW）, the subjects of BW have superior influence towards direction and show a decline significantly in speed and stride length of walking, and a increase significantly in single-step length, double support length and the first double support length. While the two related joint angular displacement show striking similarity during both model of walking. Ankle moment mode in FW and phase inversion BW also shows similarity surprisingly. However, knee, and hip joints moment mode are not so similar to ankle joint. Joint power of knee, ankle and hip have larger differences in both of walking and conclude the main driving force and shock absorption of BW coming from the ankle and knee, hip joint can produce hardly any push power. EMG data show. When the subjects were FW, EMG activity of rectus femoris was more inactive than the EMG activity when the subjects were BW. When the subjects were FW, EMG activity of biceps femoris, vastus medialis and vastus lateralis were more active than the EMG activity when the subjects were BW. When the subjects were FW, EMG activity of medial gastroc- nemius, lateral gastrocnemius, tibialis anterior and soleus were more actively than the EMG activity when the subjects were FW. EMG data further provide ev- idence for the power source of the ankle joint in BW. In FW, its power source is as mainly undertaken by the hip and knee joint. Conclusions ： Practice of BW can modify the neural mechanisms and contribute to motor learning which is beneficial to the impaired musculoskeletal function re-education. Patella femoral joint endure lower reaction force from the ground during BW, therefore, BW is beneficial to the recover for injured patients overusing the lower extremity.