Doorenbosch C A, Harlaar J, Roebroeck M E, Lankhorst G J
Department of Rehabilitation Medicine, Free University Hospital, Amsterdam, The Netherlands.
J Biomech. 1994 Nov;27(11):1299-307. doi: 10.1016/0021-9290(94)90039-6.
In this study, two different strategies of rising from a chair were compared, using integrated biomechanical and electromyographic analyses. Nine healthy subjects were instructed to rise using two different strategies: natural sit-to-stand transfer (NSTS) and a sit-to-stand transfer with full flexion of the trunk (FSTS). Sagittal kinematics and ground reaction forces were registered. Muscle activity of nine muscles of the right leg were recorded by means of surface EMG. All signals were synchronized at seat-off. The results show that no differences occur between the kinematics of knee and ankle, whereas the hip flexion is, as expected, higher during FSTS. The higher moment about the knee during NSTS is shifted to proportionally higher moments about the hip and ankle during FSTS. It is mainly the differences in the EMG-levels of the biarticular hip and knee muscles which might explain the differences in net moment. These results are in accordance with a theory about a particular role of biarticular muscles. On the other hand, the shift from knee to ankle cannot be associated with a particular increase in activity of the biarticular m.gastrocnemius. It is hypothesized that about the ankle, control of stability is preferred over movement control. An important conclusion for rehabilitation medicine is that a lower net moment about the knee in FSTS does not automatically imply that this reduces the load on the knee extensors.
在本研究中，运用综合生物力学和肌电图分析，比较了从椅子上起身的两种不同策略。九名健康受试者被要求使用两种不同策略起身：自然坐立转移（NSTS）和躯干完全屈曲的坐立转移（FSTS）。记录矢状面运动学和地面反作用力。通过表面肌电图记录右腿九块肌肉的肌肉活动。所有信号在离座时同步。结果表明，膝关节和踝关节的运动学之间没有差异，而正如预期的那样，FSTS期间髋关节屈曲更高。NSTS期间膝关节较高的力矩在FSTS期间转移为髋关节和踝关节成比例更高的力矩。主要是双关节髋部和膝部肌肉的肌电图水平差异可能解释了净力矩的差异。这些结果与关于双关节肌肉特定作用的理论一致。另一方面，从膝关节到踝关节的转移与双关节腓肠肌活动的特定增加无关。据推测，在踝关节处，稳定性控制优于运动控制。康复医学的一个重要结论是，FSTS期间膝关节较低的净力矩并不自动意味着这会减轻膝关节伸肌的负荷。
