基于膝关节支撑的人体坐立转换运动轨迹研究

目的研究基于膝关节支撑的人体坐立转换轨迹及运动学规律,为设计具有膝关节支撑的转移辅具提供依据。方法2019年4月至6月,招募20例健康志愿者,按照身高和性别分为三组,在膝关节支撑的前提下分别进行足间距离为20 cm和30 cm的坐立转换试验。每个试验重复两次,间隔1 min。采用高清相机记录试验过程中每个受试者肩部(腋窝处)和膝关节处的运动轨迹,分析不同身高和体质量受试者的运动学规律。结果身高172 cm以下的受试者,足间距离为20 cm时身体前倾距离小于30 cm时;身高173 cm以上的受试者,足间距离为30 cm时身体前倾距离小于20 cm时。体质量指数(BMI)<23.9 kg/m^2的受试者,足间距离为20 cm时躯干前屈位移小于30 cm时;BMI>23.9 kg/m^2的受试者,足间距离为30 cm时躯干前屈位移小于20 cm时。受试者坐立转换过程平均用时(1.7±0.05)s。结论坐立转换过程中,不同足间距离影响关节的伸展方式以及躯干前屈的位移和身体前倾的距离。随着身高和体质量的增加,适当增大足间距离能够降低人体在坐立转换过程的难度,且随着BMI值的增加,坐立转换所用时间也随之增加;女性坐立转换时间略高于男性。

Knee Support-based Study on Sit to Stand Transfer Trajectory of Human Body

Objective To study the human body's sit to stand transfer trajectory and kinematics based on knee joint support to provide a basis for designing the transfer aid with knee joint support.Methods From April to June, 2019, 20 healthy volunteers were recruited and divided into three groups according to height and gender. Under the premise of knee support, the sit to stand transfer experiments with 20 cm and 30 cm between feet were conducted respectively. All subjects were repeated twice for each experiment with an interval of one minute. High-definition camera was used to record the motion trajectories of each subject's shoulder (armpit) and knee joint during the experiment, and the kinematics rules of subjects with different heights and masses were analyzed.Results The body forward leaning displacement was less with 20 cm between feet than with 30 cm for subjects less than 172 cm tall; and was less with 30 cm than with 20 cm for subjects more than 173 cm tall. The forward flexion displacement of trunk was less with 20 cm between feet than with 30 cm for subjects with body mass index (BMI) < 23.9 kg/m ²; and was less with 30 cm than with 20 cm for subjects with BMI > 23.9 kg/m ². The average time during sit to stand transfer was (1.7±0.05) s.Conclusion In the process of sit to stand transfer, distance between feet may affect the way of joint extension, the body forward leaning distance and the forward flexion displacement of trunk. With the increase of height and mass, appropriate increase of distance between feet can reduce the difficulty of sit to stand transfer. With the increase of BMI, the time of sit to stand transfer also increases. The time spent on sit to stand transfer is more in female than in male.