Kuhtz-Buschbeck J P, Boczek-Funcke A, Illert M, Weinhardt C
Department of Physiology, Christian-Albrechts-Universität, Kiel, Germany.
Eur J Neurosci. 1994 Jul 1;6(7):1187-98. doi: 10.1111/j.1460-9568.1994.tb00617.x.
With pulsed X-ray cinematography we have analysed the angular excursions of the distal hindlimb joints (proximal interphalangeal, PIP; metatarsophalangeal, MTP; ankle) in cats walking on a treadmill. These distal joints transmit the body weight and the dynamic forces onto the ground. We have included the knee and hip joints in the analysis to relate the angular excursions of the proximal and distal joints and to verify the data previously obtained with external markers on the kinematics of the proximal joints. At the beginning of the stance phase the PIP joints flexed rapidly, the MTP joints extended slowly and the ankle and knee yielded under body weight. Whereas the PIP joints maintained a rather constant angular position of approximately 75 degrees throughout the stance phase, extension continued in the MTP joints from approximately 230 degrees at touch-down to approximately 270 degrees at the end of the stance phase. Around 50 ms before lift-off the MTP joints flexed rapidly. Early (approximately 30 ms) after lift-off this flexion changed into a slow extension. The PIP joints extended swiftly at the stance-swing transition and moderately at the end of the swing phase. During the middle part of the swing phase they flexed slowly. Small rotatory movements around the long axis of the foot took place in the last 100 ms of the swing phase. The results of this study on the distal joints are discussed in relation to the placing of the paw, to the translation of forward propulsion into a MTP movement and to the lifting of the paw (conventionally described as toe curling). They show a differentiated mechanical interaction between the different distal limb joints during these different phases, which must be known in detail to interpret the corresponding electromyographic data and to understand how the hip is moved forward over the MTP joints which serve as the final pivot during stance.
我们使用脉冲X射线摄影技术，分析了猫在跑步机上行走时后肢远端关节（近端指间关节，PIP；跖趾关节，MTP；踝关节）的角度偏移。这些远端关节将体重和动态力传递到地面。我们在分析中纳入了膝关节和髋关节，以关联近端和远端关节的角度偏移，并验证先前使用外部标记获得的关于近端关节运动学的数据。在站立阶段开始时，PIP关节迅速弯曲，MTP关节缓慢伸展，踝关节和膝关节在体重作用下屈服。在整个站立阶段，PIP关节保持相当恒定的角度位置，约为75度，而MTP关节则从触地时的约230度持续伸展至站立阶段结束时的约270度。在离地前约50毫秒，MTP关节迅速弯曲。离地后早期（约30毫秒），这种弯曲变为缓慢伸展。PIP关节在站立-摆动转换时迅速伸展，在摆动阶段结束时适度伸展。在摆动阶段的中部，它们缓慢弯曲。在摆动阶段的最后100毫秒，足部围绕长轴发生小的旋转运动。本研究关于远端关节的结果将结合爪子的放置、向前推进转化为MTP运动以及爪子的抬起（传统上称为脚趾卷曲）进行讨论。它们显示了在这些不同阶段不同远端肢体关节之间的差异化机械相互作用，要解释相应的肌电图数据以及理解在站立期间作为最终枢轴的MTP关节如何使髋关节向前移动，必须详细了解这些相互作用。
