Anterior Cruciate Ligament Loading Increases With Pivot-Shift Mechanism During Asymmetrical Drop Vertical Jump in Female Athletes

Abstract

Background: Frontal plane trunk lean with a side-to-side difference in lower extremity kinematics during landing increases unilateral knee abduction moment and consequently anterior cruciate ligament (ACL) injury risk. However, the biomechanical features of landing with higher ACL loading are still unknown. Validated musculoskeletal modeling offers the potential to quantify ACL strain and force during a landing task. Purpose: To investigate ACL loading during a landing and assess the association between ACL loading and biomechanical factors of individual landing strategies. Study Design: Descriptive laboratory study. Methods: Thirteen young female athletes performed drop vertical jump trials, and their movements were recorded with 3-dimensional motion capture. Electromyography-informed optimization was performed to estimate lower limb muscle forces with an OpenSim musculoskeletal model. A whole-body musculoskeletal finite element model was developed. The joint motion and muscle forces obtained from the OpenSim simulations were applied to the musculoskeletal finite element model to estimate ACL loading during participants’ simulated landings with physiologic knee mechanics. Kinematic, muscle force, and ground-reaction force waveforms associated with high ACL strain trials were reconstructed via principal component analysis and logistic regression analysis, which were used to predict trials with high ACL strain. Results: The median (interquartile range) values of peak ACL strain and force during the drop vertical jump were 3.3% (–1.9% to 5.1%) and 195.1 N (53.9 to 336.9 N), respectively. Four principal components significantly predicted high ACL strain trials, with 100% sensitivity, 78% specificity, and an area of 0.91 under the receiver operating characteristic curve ( P < .001). High ACL strain trials were associated with (1) knee motions that included larger knee abduction, internal tibial rotation, and anterior tibial translation and (2) motion that included greater vertical and lateral ground-reaction forces, lower gluteus medius force, larger lateral pelvic tilt, and increased hip adduction. Conclusion: ACL loads were higher with a pivot-shift mechanism during a simulated landing with asymmetry in the frontal plane. Specifically, knee abduction can create compression on the posterior slope of the lateral tibial plateau, which induces anterior tibial translation and internal tibial rotation. Clinical Relevance: Athletes are encouraged to perform interventional and preventive training to improve symmetry during landing.

Muscle Force Contributions to Anterior Cruciate Ligament Loading

“…In silico approaches use computer simulation techniques that often rely on data collection (e.g., via motion capture data) from healthy organisms. In the context of muscle forces and ACL loading, this involves employing musculoskeletal modelling [ 26 , 67 – 79 ] and/or finite element modelling [ 71 , 80 – 84 ] techniques. The use of these techniques offers several distinct advantages.…”

“…Subsequently, the anterior shear force contributions of the quadriceps were likely overestimated. Two studies employed modelling approaches that explored ‘high risk’ and ‘low risk’ (as defined by the peak ACL force or strain) simulations of ski landing [ 78 ] or a bilateral drop jump [ 84 ]. During the ski jump [ 78 ], the ‘high risk’ condition had higher vasti activation, but also had lower hamstring and soleus activation.…”

“…During the ski jump [ 78 ], the ‘high risk’ condition had higher vasti activation, but also had lower hamstring and soleus activation. During the drop-jump simulations [ 84 ], the ‘high risk’ condition had lower muscle forces, with the exception of the vastus intermedius (as well as the iliopsoas and medial gastrocnemius). Whilst both of these studies suggest an association between quadriceps activation/force and ACL loading, the simultaneous changes in the activation/force of other muscles likely confound the conclusions.…”

“…A recent modelling study found that a greater knee valgus moment was associated with lower gluteus medius muscle force (as part of a multivariate regression model) during a drop vertical jump [ 118 ]. This same research group utilised a finite element modelling approach that showed ‘high risk’ (i.e., higher ACL strain) bilateral drop jump simulations were associated with lower gluteus medius force [ 84 ]; however, the ‘high risk’ condition was also characterised by potentially confounding differences in kinematics and kinetics compared with the ‘low risk’ condition. Another modelling study [ 77 ] found that hip abductor fatigue (and thus, lower simulated gluteus medius force) resulted in no changes in estimated ACL force during single-leg landing compared with baseline trials, but did observe a significantly greater external knee valgus and knee external rotation moment.…”

Hamstrings Contraction Regulates the Magnitude and Timing of the Peak ACL Loading During the Drop Vertical Jump in Female Athletes

“…The time of peak ACL loading was delayed when hamstrings force was removed from the simulation. The hamstrings activation presented an increasing trend throughout the landing (see Ueno et al 53 ), whereas the time of peak vertical GRF, knee abduction, internal tibial rotation, and anterior tibial translation, which induce higher ACL strain, were observed from 50 to 90 milliseconds (see Ueno et al 54 for more detailed knee kinematics). When hamstrings force was applied, 17 of 37 trials presented the peak ACL strain within 10 milliseconds after initial ground contact, where the knee flexion angle was at its minimum.…”