Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA.
Department of Orthopaedic Surgery, Duke University, Durham, North Carolina, USA.
Am J Sports Med. 2022 Aug;50(10):2688-2697. doi: 10.1177/03635465221107085. Epub 2022 Jul 19.
Quadriceps loading of the anterior cruciate ligament (ACL) may play a role in the noncontact mechanism of ACL injury. Musculoskeletal modeling techniques are used to estimate the intrinsic force of the quadriceps acting at the knee joint.
PURPOSE/HYPOTHESIS: The purpose of this paper was to develop a novel musculoskeletal model of in vivo quadriceps force during dynamic activity. We used the model to estimate quadriceps force in relation to ACL strain during a single-leg jump. We hypothesized that quadriceps loading of the ACL would reach a local maximum before initial ground contact with the knee positioned in extension.
Descriptive laboratory study.
Six male participants underwent magnetic resonance imaging in addition to high-speed biplanar radiography during a single-leg jump. Three-dimensional models of the knee joint, including the femur, tibia, patellofemoral cartilage surfaces, and attachment-site footprints of the patellar tendon, quadriceps tendon, and ACL, were created from the magnetic resonance imaging scans. The bone models were registered to the biplanar radiographs, thereby reproducing the positions of the knee joint at the time of radiographic imaging. The magnitude of quadriceps force was determined for each knee position based on a 3-dimensional balance of the forces and moments of the patellar tendon and the patellofemoral cartilage contact acting on the patella. Knee kinematics and ACL strain were determined for each knee position.
A local maximum in average quadriceps force of approximately 6500 N (8.4× body weight) occurred before initial ground contact. ACL strain increased concurrently with quadriceps force when the knee was positioned in extension.
This novel participant-specific modeling technique provides estimates of in vivo quadriceps force during physiologic dynamic loading. A local maximum in quadriceps force before initial ground contact may tension the ACL when the knee is positioned in extension.
These data contribute to understanding noncontact ACL injury mechanisms and the potential role of quadriceps activation in these injuries.
股四头肌对前交叉韧带（ACL）的加载可能在 ACL 非接触性损伤机制中发挥作用。肌肉骨骼建模技术用于估计膝关节处股四头肌的内在力。
目的/假设：本文的目的是开发一种新的活体股四头肌力在动态活动中的肌肉骨骼模型。我们使用该模型来估计单腿跳时 ACL 应变相关的股四头肌力。我们假设在膝关节伸展的初始地面接触之前，ACL 处的股四头肌加载会达到局部最大值。
描述性实验室研究。
六名男性参与者在单腿跳期间接受了磁共振成像，此外还进行了高速双平面射线照相。从磁共振成像扫描中创建了膝关节的三维模型，包括股骨、胫骨、髌股软骨表面以及髌腱、股四头肌肌腱和 ACL 的附着点足迹。骨骼模型被注册到双平面射线照片，从而再现了射线照相成像时的膝关节位置。根据髌腱和髌股软骨接触作用于髌骨的力和力矩的三维平衡，确定了每个膝关节位置的股四头肌力的大小。确定了每个膝关节位置的膝关节运动学和 ACL 应变。
在初始地面接触之前，平均股四头肌力约为 6500 N（8.4×体重）出现局部最大值。当膝关节处于伸展位置时，ACL 应变与股四头肌力同时增加。
这种新的基于参与者的建模技术提供了在生理动态加载下活体股四头肌力的估计。在膝关节伸展的初始地面接触之前，股四头肌力的局部最大值可能会在膝关节伸展时拉紧 ACL。
这些数据有助于理解非接触性 ACL 损伤机制以及股四头肌激活在这些损伤中的潜在作用。
