床垫支撑力和下肢屈曲角度对膝髋关节生物力学的影响

对人体仰卧屈腿姿势下膝关节和髋关节进行生物力学分析,建立了膝关节和髋关节关节力和肌肉力的计算公式,并探究了床垫支撑力和下肢屈曲角度对膝关节和髋关节关节力和肌肉肌力大小的影响。结果表明:当膝关节屈曲角度在0°～80°范围内时,随着膝关节屈曲角度的增大,膝关节受力及股四头肌肌力逐渐减小; 当膝关节屈曲角度大于80°时,膝关节力和股四头肌肌力保持稳定,且数值较小; 髋关节屈曲在小于60°范围内的关节力和髂腰肌肌力相对较小; 随着床垫对足部和臀部支撑力的增大,髋关节和膝关节的关节力和肌力均增大。人体在睡眠过程中膝关节和髋关节屈曲角度多小于90°,而在低于90°的屈曲姿势下膝关节肌力和髋关节力较大,肌肉持续施力,容易产生疲劳,因此睡眠过程中人体持续保持屈腿姿势的时间有限,同时从生物力学角度阐明了人体在睡眠过程中需要进行睡姿调整的内在原因。
Based on biomechanical analysis on knee and hip joints in supine position with knee flexion, formulations were developed to calculate joint and muscle forces of knee and hip joints. The effect of mattress force and joint angles on joints and muscle forces of knee and hip were also investigated in this study. The results showed that, with the knee flexion angle in the range of 0°-80°, the knee joint and quadriceps femor muscle forces decreased with the increase of the knee flexion angle. The values of knee joint and muscle forces were relatively low and stable when the flexion angle was over 80°. The hip joint and iliopsoas muscle forces were relatively lower when the hip joint flexion was lower than 60°. With an increase in mattress forces on foot and hip, the joints and muscle forces of both knee and hip joints increased. During the most sleeping conditions, the angles of knee and hip joints were lower than 90° with higher knee muscle and hip joint forces, leading to muscle fatigue. It was demonstrated that the time to keep knee and hip flexion position was limited and illuminated intrinsic reason for the necessity of posture change during sleep from the angle of biomechanics