目的：确定等速向心性屈伸膝肌峰力矩、屈伸比值和双侧同名肌差值的正常范围。方法：研究对象为３６１名正常人，年龄１６～８５岁，按年龄、性别各分为６组，用Ｃｙｂｅｘ３３０型等速运动装置按标准化过程测试６０°／ｓ、１８０°／ｓ和３００°／ｓ屈、伸双膝的峰力矩。结果：除性别、年龄、体重和速度对峰力矩有影响外，身高的影响不能被体重所替代，随速度增加屈伸比值增大，双侧同名肌间的差异不显著，性别、年龄和速度与差值间均无相关，除屈肌３００°／ｓ的差值大于１０％以外，其他的差值均小于１０％。结论：通过逐步回归建立的峰力矩正常值的回归方程，以及屈伸比值和差值的均数和标准差，可为临床医学和康复医学等研究提供可靠的依据 OBJECTIVE: To determine the normal range of peak torque, flexion-extension ratio, and the difference in muscle diameter between the same side of the same muscle in constant centripetal flexion and extension. Methods: 361 normal subjects, aged 16 to 85 years old, were divided into 6 groups according to age and gender. They were tested with the Cybex330 isokinetic motion device according to a standardized procedure of 60°/s, 180°/s, and 300°/. s flexion, stretching peaks of the knee. Results: Except that gender, age, body weight and speed had influence on peak torque, the effect of height could not be replaced by body weight. With increasing speed, the flexion/extension ratio was increased. There was no significant difference between the same name muscles, gender, age and speed. There was no correlation between the differences, except that the difference of flexor 300°/s was greater than 10%, and the other differences were all less than 10%. Conclusion: The regression equation established by stepwise regression of the normal values ​​of peak moments, and the mean and standard deviation of the flexion-extension ratios and differences can provide a reliable basis for studies in clinical medicine and rehabilitation medicine.