Measurement of in vivo anterior cruciate ligament strain during dynamic jump landing

Abstract

Despite recent attention in the literature, anterior cruciate ligament (ACL) injury mechanisms are controversial and incidence rates remain high. One explanation is limited data on in vivo ACL strain during high-risk, dynamic movements. The objective of this study was to quantify ACL strain during jump landing. Marker-based motion analysis techniques were integrated with fluoroscopic and magnetic resonance (MR) imaging techniques to measure dynamic ACL strain non-invasively. First, eight subjects’ knees were imaged using MR. From these images, the cortical bone and ACL attachment sites of the tibia and femur were outlined to create 3D models. Subjects underwent motion analysis while jump landing using reflective markers placed directly on the skin around the knee. Next, biplanar fluoroscopic images were taken with the markers in place so that the relative positions of each marker to the underlying bone could be quantified. Numerical optimization allowed jumping kinematics to be superimposed on the knee model, thus reproducing the dynamic in vivo joint motion. ACL length, knee flexion, and ground reaction force were measured. During jump landing, average ACL strain peaked 55 ± 14 ms (mean and 95% confidence interval) prior to ground impact, when knee flexion angles were lowest. The peak ACL strain, measured relative to its length during MR imaging, was 12 ± 7%. The observed trends were consistent with previously described neuromuscular patterns. Unrestricted by field of view or low sampling rate, this novel approach provides a means to measure kinematic patterns that elevate ACL strains and that provide new insights into ACL injury mechanisms.

Tibio-femoral joint constraints for bone pose estimation during movement using multi-body optimization

“…In both cases, in fact, stability or coaptation of the joint should be guaranteed, although in a different manner, by a synergic activity of both passive and active intra-and periarticular structures. This hypothesis is supported by recent findings that, during a highly dynamic motion such as the landing phase of a jump, showed that the ACL length decreases during flexion by an amount similar to that obtained in the present study [30].…”

Changing Sagittal-Plane Landing Styles to Modulate Impact and Tibiofemoral Force Magnitude and Directions Relative to the Tibia

“…3,9 Investigators [10][11][12] have shown that the ground reaction forces (GRFs) that athletes incur right after foot contact in sharp decelerating motions greatly affect the magnitude of proximal tibial anterior shear forces and ACL loading. Authors 13,14 of in vivo studies who measured the amount of ACL strain during landing tasks demonstrated that the timing of peak ACL strain coincides with the peak GRF that occurs immediately after the foot contact of landing. Taylor et al 13 also demonstrated that knee-flexion angles were inversely related to ACL strain during landing.…”

“…Authors 13,14 of in vivo studies who measured the amount of ACL strain during landing tasks demonstrated that the timing of peak ACL strain coincides with the peak GRF that occurs immediately after the foot contact of landing. Taylor et al 13 also demonstrated that knee-flexion angles were inversely related to ACL strain during landing. Furthermore, the direction of peak GRF relative to the tibia in the sagittal plane has been reported to substantially affect the amount of net proximal tibial anterior shear forces immediately after the foot contact of landing.…”

The influence of muscle-tendon forces on ACL loading during jump landing: a systematic review

“…Two studies were found that analysed in vivo ACL strain by either combining markerbased motion analysis with MRI-based computational modelling and fluoroscopic imaging 16 , or direct measurements based on an implanted DVRT device 14 . Unfortunately, both in vivo studies were limited to kinematic data without reporting on muscle-tendon forces, and were thus excluded from the review.…”