Otis J C, Gould J D
J Bone Joint Surg Am. 1986 Jan;68(1):65-70.
The kinematics of the knee joint are load-dependent; the length of the lever arm of the extensor mechanism and the pathway of the instant center of rotation vary with external load. This study was conducted to determine if the maximum extensor torque-generating capacity of the knee joint is dependent on the distance from the knee joint at which the external force resisting extension is located. Maximum isometric extensor torques were measured at 90 and 30 degrees of knee flexion while the distance from the knee joint to the resisting force was varied. Our results demonstrated that the subjects generated larger maximum extensor torques, at both 90 and 30 degrees of knee flexion, when the external resisting force was positioned farther distal to the knee joint. This increase was as large as 50 per cent with the knee at 30 degrees of flexion.
膝关节的运动学与负荷相关；伸肌机制的力臂长度和瞬时旋转中心的路径会随外部负荷而变化。本研究旨在确定膝关节产生最大伸肌扭矩的能力是否取决于抵抗伸展的外力距膝关节的距离。在膝关节屈曲90度和30度时测量最大等长伸肌扭矩，同时改变从膝关节到阻力的距离。我们的结果表明，当外部阻力位于膝关节更远端时，受试者在膝关节屈曲90度和30度时均产生了更大的最大伸肌扭矩。当膝关节屈曲30度时，这种增加高达50%。
