中文摘要：

目的 研究眼外肌滑车系统在眼球大幅度内旋时的生物力学作用.方法 结合文献报道的眼外肌坐标参数,根据眼球运动的力学平衡原理,建立主动滑车力学模型,并以无滑车模型作为对照,模拟眼球在30°～ 45°范围内的内旋运动.结果 在内直肌对眼球内旋运动的贡献方面,无滑车模型的内直肌提供的作用力大于主动滑车模型,且内直肌力值明显大于生理安全极限值（约0.5N）.在模拟眼球内旋的最大角度45°处,主动滑车模型和无滑车模型模拟得到的内直肌力分别为0.508、0.782 N,后者超过生理阈值约56％.在控制眼球运动方面,主动滑车模型消耗的能量远小于无滑车模型.结论 滑车组织的存在,使得眼外肌能够以较低的耗能控制眼球运动,加强了眼外肌对眼球的牵引作用.而且,在眼球大幅度内旋运动时,主动滑车模型维持着内直肌的力学优势.

英文摘要：

Objective To study the biomechanical effect from pulley tissues of extraocular muscles on super ad- duction of the eye. Methods By the coordinate parameters of extraocular muscles reported in the literature and based on the mechanical equilibrium of eye movement, two mechanical models, active pulley model and non pul- ley model （as control）, were established to simulate eye adduction in the range of 30°-45°. Results For the con- tribution of medial rectus muscle, the non pulley model produced more force than the active pulley model to con- trol eye adduction, and its corresponding force value increasingly exceeded the physiologically safe threshold （0.5 N）. At the maximum simulative adduction of 45°, the force of medial rectus obtained by active pulley model and non pulley model was 0. 508 N and 0.782 N, respectively, and the latter was 56% greater than the safe threshold. For controlling eye adduction, the active pulley model consumed much less energy than the non pulley model. Conclusions Due to the existence of pulley tissues, extraocular muscles could control eye adduction by consuming less biological energy and reinforce the ocular derivation. In addition, with the active pulley, the medi- al rectus muscle could maintain its mechanical advantage under super adduction of the eye.