Association Between Knee Anatomic Metrics and Biomechanics for Male Soldiers Landing With Load

Abstract

Background: Anterior cruciate ligament (ACL) injury is a military occupational hazard that may be attributed to an individual’s knee biomechanics and joint anatomy. This study sought to determine if greater flexion when landing with load resulted in knee biomechanics thought to decrease ACL injury risk and whether knee biomechanics during landing relate to knee anatomic metrics. Hypothesis: Anatomic metrics regarding the slope and concavity of the tibial plateau will exhibit a significant relation to the increased anterior shear force on the knee and decreased knee flexion posture during landing with body-borne load. Study Design: Descriptive laboratory study. Methods: Twenty male military personnel completed a drop landing task with 3 load conditions: light (~6 kg), medium (15% body weight), and heavy (30% body weight). Participants were divided into groups based on knee flexion exhibited when landing with the heavy load (high- and low-Δflexion). Tibial slopes and depth were measured on weightbearing volumetric images of the knee obtained with a prototype cone beam computed tomography system. Knee biomechanics were submitted to a linear mixed model to evaluate the effect of landing group and load, with the anatomic metrics considered covariates. Results: Load increased peak proximal anterior tibial shear force ( P = .034), knee flexion angle ( P = .024), and moment ( P = .001) during landing. Only the high flexion group increased knee flexion ( P < .001) during weighted landings with medium and heavy loads. The low flexion group used greater knee abduction angle ( P = .030) and peak proximal anterior tibial shear force ( P = .034) when landing with load. Anatomic metrics did not differ between groups, but ratio of medial-to-lateral tibial slope and medial tibial depth predicted peak proximal anterior tibial shear force ( P = .009) and knee flexion ( P = .034) during landing, respectively. Conclusion: Increasing knee flexion is an attainable strategy to mitigate risk of ACL injury, but certain individuals may be predisposed to knee forces and biomechanics that load the ACL during weighted landings. Clinical Relevance: The ability to screen individuals for anatomic metrics that predict knee flexion may identify soldiers and athletes who require additional training to mitigate the risk of lower extremity injury.

Weighted Vest Load Arrangement and Data Normalization Effects on Lower Limb Biomechanics During Countermovement Jump Landings

“…Other studies also show this behavior because an increased system mass reduces the maximum jump height [38], [68]. Previous studies have reported a 5-10% increase in GRFs [63], [69], [70] in the case of drop jump landings, where jump height does not need to be considered for normalization since the landing height is fixed. When comparing male to female jumpers, it has been reported that females withstand higher GRF due to lesser lower limb stiffness [25], which is the opposite of our results.…”

Morphological Risk Factors for Posterior Cruciate Ligament Tear and Tibial Avulsion Injuries of the Tibial Plateau and Femoral Condyle

“…22 In a prospective study, Kiapour et al 23 found that decreased MTD was associated with increased knee laxity 7 years after ACL reconstruction. Although further verification is needed, the results from Kaplan et al 20 implied that to some extent MTD may predict peak knee flexion angle during landing under load and a 1-mm decrease in MTD increases peak knee flexion by 7.1°. Increasing knee flexion is effective in reducing the risk of ACL injury 20,32 ; however, it may increase the force applied to the PCL.…”

“…Although further verification is needed, the results from Kaplan et al 20 implied that to some extent MTD may predict peak knee flexion angle during landing under load and a 1-mm decrease in MTD increases peak knee flexion by 7.1°. Increasing knee flexion is effective in reducing the risk of ACL injury 20,32 ; however, it may increase the force applied to the PCL. 41 Nonetheless, among male patients with contact PCLIT, no significant difference was identified in MTD as compared with the controls.…”

Az emberi térd, csípő és gerinc biomechanikai jellemzői, valamint terhelés hatására létrejött elváltozásainak áttekintő elemzése

“…Véleményük szerint is fenti anatómiai, biomechanikai paraméterek szűrésével azonosíthatók lesznek azok a személyek, akik kiegészítő gyakorlatok bevezetésével csökkenteni tudják az alsó végtagi sérülések kockázatát. 49 Természetesen katonák esetén a túlterhelés mellett a kiképzés során, illetve a harctéren szerzett sérülések is okozhatnak térdízületi problémákat. Rivera és munkatársai a civil lakossággal összehasonlítva vizsgálták a térdízületi kopás prevalenciáját térdtáji sérüléseket elszenvedett katonák esetén.…”