There is a high risk of serious injury to the lower limbs in a human drop landing. However, cats are able to jump from the same heights without any sign of injury, which is attributed to the excellent performance of their limbs in attenuating the impact forces. The bionic study of the falling cat landing may therefore contribute to improve the landing-shock absorbing ability of lower limbs in humans. However, the contributions of cat limb joints to energy absorption remain unknown. Accordingly, a motion capture system and plantar pressure measurement platform were used to measure the joint angles and vertical ground reaction forces of jumping cats, respectively. Based on the inverse dynamics, the joint angular velocities, moments, powers, and work from different landing heights were calculated to expound the synergistic mechanism and the dominant muscle groups of cat limb joints. The results show that the buffering durations of the forelimbs exhibit no significant difference with increasing height while the hindlimbs play a greater role than the forelimbs in absorbing energy when jumping from a higher platform. Furthermore, the joint angles and angular velocities exhibit similar variations, indicating that a generalized motor program can be adopted to activate limb joints for different landing heights. Additionally, the elbow and hip are recognized as major contributors to energy absorption during landing. This experimental study can accordingly provide biological inspiration for new approaches to prevent human lower limb injuries.

中文翻译：

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猫着陆过程中四肢关节对能量吸收的贡献。

在人坠落时，下肢有严重受伤的高风险。但是，猫能够从相同的高度跳下而没有受伤的迹象，这是由于猫的肢体在减轻冲击力方面的出色表现。因此，对下落的猫着陆的仿生研究可能有助于提高人类下肢的着陆震动吸收能力。然而，猫肢关节对能量吸收的贡献仍然未知。因此，运动捕捉系统和足底压力测量平台分别用于测量跳跃猫的关节角度和垂直地面反作用力。根据逆动力学，关节的角速度，力矩，功率，并计算了不同着陆高度下的功，以阐明猫肢关节的协同机制和优势肌肉群。结果表明，前肢的缓冲时间随高度的增加没有显着差异，而后肢在从更高的平台上跳跃时在吸收能量方面比前肢发挥更大的作用。此外，关节角度和角速度表现出相似的变化，表明可以采用通用的电机程序来激活针对不同着陆高度的肢体关节。此外，肘部和臀部被认为是着陆过程中能量吸收的主要贡献者。因此，该实验研究可以为预防人类下肢受伤的新方法提供生物学灵感。结果表明，前肢的缓冲时间随高度的增加没有显着差异，而后肢在从更高的平台上跳跃时在吸收能量方面比前肢发挥更大的作用。此外，关节角度和角速度表现出相似的变化，表明可以采用通用的电机程序来激活针对不同着陆高度的肢体关节。此外，肘部和臀部被认为是着陆过程中能量吸收的主要贡献者。因此，该实验研究可以为预防人类下肢受伤的新方法提供生物学灵感。结果表明，前肢的缓冲时间随高度的增加没有显着差异，而后肢在从更高的平台上跳跃时在吸收能量方面比前肢发挥更大的作用。此外，关节角度和角速度表现出相似的变化，表明可以采用通用的电机程序来激活针对不同着陆高度的肢体关节。另外，肘部和臀部被认为是着陆过程中能量吸收的主要贡献者。因此，该实验研究可以为预防人类下肢受伤的新方法提供生物学灵感。