Marc F. Norcross

Purpose The capacity to explosively contract quadriceps within the critical timeframe associated with anterior cruciate ligament (ACL) injury, quantified by the rate of torque development, is potentially essential for safe landing mechanics. This study aimed to investigate the influence of explosive quadriceps strength on ACL‐related sagittal‐plane landing mechanics in females with and without ACL reconstruction (ACLR). Methods Quadriceps explosive strength and landing mechanics were assessed in 19 ACLR and 19 control females during isometric contractions and double‐ and single‐leg jump landings. A stepwise multiple linear regression model determined the variance in each of the landing biomechanics variables for the ACLR limb and nondominant limb of controls that could be explained by the group, rate of torque development and/or their interaction. If peak kinetic variables could be predicted by the rate of torque development or interaction, additional analyses were conducted, accounting for knee flexion as a covariate in the regression model. Results During single‐leg landings, ACLR females exhibited greater knee flexion at initial contact than controls ( p = 0.04). Greater quadriceps rate of torque development predicted higher peak posterior ground reaction force and anterior tibial shear force in both groups ( p = 0.04). However, after controlling for knee flexion angle at those peak forces, quadriceps rate of torque development was not predictive. In double‐leg landings, greater explosive quadriceps strength was associated with quicker attainment of peak knee extension moment and posterior ground reaction force in the ACLR limb ( p = 0.03). Conclusion Regardless of ACL injury status, females with greater explosive quadriceps strength adopted safer single‐leg landings through increased knee flexion, potentially mitigating ACL loading despite encountering higher peak forces. During double‐leg landings, a greater explosive quadriceps strength of the ACLR limb is associated with faster achievement of peak force upon landing. Incorporating explosive quadriceps strengthening into post‐ACLR rehabilitation and injury prevention programmes may enhance landing mechanics for reducing primary and subsequent ACL injury risks. Level of Evidence Level II.

Clinical Scenario : Delay in surgery for anterior cruciate ligament (ACL) injuries increases the risk of complications including secondary injuries. Previous research has shown individuals with public insurance have greater delays in care for a variety of health conditions. Clinical Question : In pediatric patients with ACL injuries, is the time from injury to surgery longer for patients with public insurance than patients with private insurance? Summary of Key Findings : Four studies met the inclusion criteria. All studies reported a greater wait time for surgery in pediatric patients with public insurance. Clinical Bottom Line : There is moderate evidence indicating that there is a delay in ACL surgery for pediatric patients with public insurance compared to those with private insurance. Strength of Recommendation : Grade B evidence exists that there is a delay in surgery for ACL injuries in pediatric patients with public insurance compared to those with private insurance.