Study On The Gait Stability Of The Elderly During Weight Carrying With Different Stop Mode

Walking is a process of periodic repetition,and gait termination is one of the stages,which requires the transition from a stable state to another stable state.Sudden stop is a special form of gait termination,which requires higher control ability of body posture,and is easy to lose balance and fall.Stability at gait termination is regulated by multiple factors,including the nervous system and musculoskeletal system.People should make necessary adjustments to avoid falling when their gait stops,especially the elderly.The decrease of gait termination ability is an important factor leading to falls in the elderly group.Therefore,it is of great significance to analyze the influence of different stopping modes on gait stability in the elderly.According to the investigation,daily grocery shopping is an indispensable activity for the elderly.The weight of daily grocery shopping is generally about 1.5kg-5kg.Black non-reflective dumbbells are used to simulate heavy weights.In this study,12 elderly men over the age of 65 were recruited as subjects.In the experiment,as a uniform variable,subjects were required to step their left foot first and complete the tests of emergency stop and planned stop at a normal speed with different loading methods.VICON 3d motion capture system and 5 AMTI biomechanical force measuring platforms(600mmx400mm)were used to collect the parameters in the process of motion.5 force measuring platforms were embedded in the middle of the test platform to ensure that the surface of the force measuring platform was level with that of the test platform.VICON system can identify key positions through the reflective marker balls pasted on the 16 positions of the lower limbs,and establish a lower limb model by inputting specific parameters to ensure that the Noraxon surface EMG telemetry system is synchronized with VICON and the human surface EMG signals are collected.SPSS statistical software,Matlab programming and Origin drawing software were used for processing and analysis,and the following conclusions were drawn through walking experiment and paired sample T test:(1)At the moment when the gait stops,the stability of the lower limbs is affected by the stop mode and load bearing mode.When the emergency stop occurs,it shows greater instability.In order to increase its stability,the fluctuation range of the ankle joint of the braking leg is reduced and the toe flexion of the ankle joint is increased.In addition,it is easier to stop without loading during a sudden stop.One-hand loading requires increasing the Angle of the trailing leg ankle joint to maintain body stability.In the case of weight-bearing,the elderly will increase their body stability by reducing hip fluctuation range and increasing hip flexion Angle.(2)At the same time,the muscle activity of the braking leg is higher during the emergency stop.Since the stop action occurs without prior warning,the muscle contraction level of the braking leg is increased to reduce the forward momentum so as to maintain the stability of the body.In addition,it was observed that the muscle activity level of the braking leg was significantly higher than that of the trailing leg during the emergency stop,indicating that the braking leg played a key role in the emergency.Moreover,the single hand load increases the work difference between the braking leg and the following leg muscles,leading to lateral instability.During the emergency stop,the braking leg LTA needs higher muscle activity to control the Angle of toe curve of the ankle joint.Therefore,in the daily life of the elderly to avoid excessive weight bearing,it is recommended that the hands load,and strengthen the lower limb muscle training.The conclusion of this study can provide guidance and Suggestions for the stability of the elderly when gait stops,and provide theoretical basis and design ideas for the design of fitness equipment and mobile terminals to exercise the balance ability of lower limbs.