Department of Physical Therapy, California State University, Sacramento, CA 95819-6020, USA.
J Orthop Sports Phys Ther. 2012 Mar;42(3):208-20. doi: 10.2519/jospt.2012.3768. Epub 2012 Feb 29.
There is a growing body of evidence documenting loads applied to the anterior cruciate ligament (ACL) for weight-bearing and non-weight-bearing exercises. ACL loading has been quantified by inverse dynamics techniques that measure anterior shear force at the tibiofemoral joint (net force primarily restrained by the ACL), ACL strain (defined as change in ACL length with respect to original length and expressed as a percentage) measured directly in vivo, and ACL tensile force estimated through mathematical modeling and computer optimization techniques. A review of the biomechanical literature indicates the following: ACL loading is generally greater with non-weight-bearing compared to weight-bearing exercises; with both types of exercises, the ACL is loaded to a greater extent between 10° to 50° of knee flexion (generally peaking between 10° and 30°) compared to 50° to 100° of knee flexion; and loads on the ACL change according to exercise technique (such as trunk position). Squatting with excessive forward movement of the knees beyond the toes and with the heels off the ground tends to increase ACL loading. Squatting and lunging with a forward trunk tilt tend to decrease ACL loading, likely due to increased hamstrings activity. During seated knee extension, ACL force decreases when the resistance pad is positioned more proximal on the anterior aspect of the lower leg, away from the ankle. The evidence reviewed as part of this manuscript provides objective data by which to rank exercises based on loading applied to the ACL. The biggest challenge in exercise selection post-ACL reconstruction is the limited knowledge of the optimal amount of stress that should be applied to the ACL graft as it goes through its initial incorporation and eventual maturation process. Clinicians may utilize this review as a guide to exercise selection and rehabilitation progression for patients post-ACL reconstruction.
越来越多的证据记录了负重和非负重运动中对前交叉韧带（ACL）的负荷。ACL 负荷已通过反向动力学技术进行量化，该技术可测量胫股关节的前向剪切力（主要由 ACL 限制的净力）、直接在体内测量的 ACL 应变（定义为 ACL 长度相对于原始长度的变化，并表示为百分比），以及通过数学建模和计算机优化技术估计的 ACL 拉伸力。对生物力学文献的回顾表明：与负重运动相比，非负重运动中的 ACL 负荷通常更大；对于这两种类型的运动，在 10°到 50°的膝关节屈曲范围内（通常在 10°到 30°之间达到峰值），ACL 的负荷比在 50°到 100°的膝关节屈曲范围内更大；根据运动技术（如躯干位置），ACL 上的负荷会发生变化。膝盖过度向前超出脚趾且脚跟离地的深蹲会增加 ACL 的负荷。膝盖弯曲和前倾斜的深蹲会降低 ACL 的负荷，可能是因为腘绳肌活动增加。在坐姿膝关节伸展中，当阻力垫位于小腿前侧更靠近脚踝的近端时，ACL 力会减小。作为本手稿一部分审查的证据提供了基于 ACL 施加的负荷对运动进行排名的客观数据。ACL 重建后选择运动的最大挑战是对 ACL 移植物施加的最佳压力量的知识有限，因为它经历了最初的整合和最终的成熟过程。临床医生可以将本综述用作 ACL 重建后患者选择运动和康复进展的指南。
