The Influence of Quadriceps Strength and Rate of Torque Development on the Recovery of Knee Biomechanics During Running After Anterior Cruciate Ligament Reconstruction

Abstract

Background: After anterior cruciate ligament reconstruction (ACLR), altered surgical knee biomechanics during running is common. Although greater quadriceps strength is associated with more symmetrical running knee kinetics after ACLR, abnormal running mechanics persist even after resolution of quadriceps strength deficits. As running is a submaximal effort task characterized by limited time to develop knee extensor torque, quadriceps rate of torque development (RTD) may be more closely associated with recovery of running knee mechanics than peak torque (PT). Purpose: To assess the influence of recovery in quadriceps PT and RTD symmetry on knee kinematic and kinetic symmetry during running over the initial 2 years after ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 39 Division I collegiate athletes (106 testing sessions; 19 female) completed serial isometric performance testing and running analyses between 3 and 24 months after ACLR. Athletes performed maximal and rapid isometric knee extension efforts with each limb to assess PT and RTD between-limb symmetry indices (PTLSI and RTDLSI), respectively. Peak knee flexion difference (PKFDIFF) and peak knee extensor moment limb symmetry index (PKEMLSI) during running were computed. Multivariable linear mixed-effects models assessed the influence of PTLSI and RTDLSI on PKFDIFF and PKEMLSI over the initial 2 years after ACLR. Results: Significant main effects of RTDLSI ( P < .001) and time ( P≤ .02) but not PTLSI ( P≥ .24) were observed for both PKFDIFF and PKEMLSI models. For a 10% increase in RTDLSI, while controlling for PTLSI and time, a 0.9° (95% CI, 0.5°-1.3°) reduction in PKFDIFF and a 3.5% (95% CI, 1.9%-5.1%) increase in PKEMLSI are expected. For every month after ACLR, a 0.2° (95% CI, 0.1°-0.4°) reduction in PKFDIFF and a 1.3% (95% CI, 0.6%-2.0%) increase in PKEMLSI are expected, controlling for PTLSI and RTDLSI. Conclusion: Quadriceps RTDLSI was more strongly associated with symmetrical knee biomechanics during running compared with PTLSI or time throughout the first 2 years after ACLR.

Differential influence of quadriceps rate of torque development on single‐ and double‐leg landing mechanics in anterior cruciate ligament reconstructed and control females

“…Post-ACLR individuals have shown early quadriceps rate of torque development deficits in both limbs compared to controls [20,32,35,49] and those with reduced explosive quadriceps strength exhibit decreased knee flexion and excursion [19,28] and delayed development of knee extension moment [19] during functional tasks, suggesting challenges in generating extension moment rapidly and a stiffer landing strategy to minimize knee extension moment demand [44]. Given the potential link between explosive quadriceps strength and landing mechanics [16,17,19,20,28,29], this study aimed to investigate the influence of quadriceps rate of torque development on sagittal-plane landing mechanics in females with and without ACLR during double-and single-leg landings. The hypothesis was that greater quadriceps rate of torque development would be associated with more favourable sagittal-plane landing mechanics, characterized by reduced magnitude and delayed timing of peak loading forces, coupled with greater peak knee flexion angle at initial contact.…”

Effect of Running Speed on Knee Biomechanics in Collegiate Athletes Following Anterior Cruciate Ligament Reconstruction

“…As quadriceps neuromuscular performance is more impaired early postoperatively (18), athletes may not possess the adequate quadriceps torque generating capacity necessary to respond to an increase in running speed. This is supported by the fact that running mechanics post-ACLR have been associated with quadriceps strength (2,19) and rate of torque development (7,20). Therefore, athletes post-ACLR may adopt a maladaptive movement strategy to run at a faster speed.…”