Explosive Quadriceps Strength Symmetry and Landing Mechanics Limb Symmetry After Anterior Cruciate Ligament Reconstruction in Females

Abstract

Context Emerging evidence suggests that lower quadriceps rate of torque development (RTD) following anterior cruciate ligament reconstruction (ACLR) may be associated with altered landing mechanics. However, the influence of quadriceps RTD magnitude and RTD limb symmetry on landing mechanics limb symmetry remains unknown. Objective To assess the influence of quadriceps RTD magnitude and RTD limb symmetry on sagittal plane landing mechanics limb symmetry in females with and without ACLR during functional landing tasks. Design Cross-Sectional Study Setting Laboratory Patients or Other Participants Thirty-eight females (ACLR=19, 19.2±1.8 years-old, 164.1±7.0 cm, 63.8±7.6 kg, Time after surgery: 20.1±9.5 months; Control=19, 21.1±3.3 years-old, 167.3±7.3 cm, 67.3±9.3 kg). Main Outcome Measure(s) Landing mechanics were assessed during double-leg and single-leg jump-landing tasks (DL and SL), and a side-cut task (SC). Quadriceps RTD was collected during isometric muscle contractions. Separate stepwise multiple linear regression models determined the amount of variance in limb symmetry in sagittal plane knee moment at initial contact (IC), peak vertical ground reaction force (vGRF), and loading rate that could be explained by quadriceps RTD magnitude or RTD limb symmetry, group (ACLR or Control), and their interaction. Results In ACLR females, greater quadriceps RTD limb symmetry was associated with greater symmetry in sagittal plane knee moment at IC during DL (P=.004). Peak vGRF and loading rate could not be predicted by quadriceps RTD magnitude or RTD limb symmetry, group, or their interaction during all tasks. Conclusions Developing greater quadriceps RTD symmetry, but not RTD magnitude, likely enables more symmetrical sagittal plane knee landing mechanics during double-leg task in ACLR females, and thus may reduce the risk of a second ACL injury. Such protective effect was not found during single-leg tasks that may not allow for a compensatory landing mechanism of shifting load to the uninvolved limb as is possible during a double-leg task.

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

“…During jumping tasks, RTD LSI accounted for only 21% of the variance in knee extensor moment symmetry at initial contact during the landing phase of a double-leg drop jump, but was not a significant predictor during the single-leg drop jump in a cross-sectional study (mean, 20.1 6 9.1 months after ACLR; only female athletes). 19 Specific to running, a crosssectional study at a mean of 48.0 6 25.0 months after ACLR athletes demonstrated a low correlation between isokinetic PT and rate of knee extensor moment (r = 0.38) and between RTD (0-100 ms from onset) and rate of knee extensor moment (r = 0.26). 35 A prospective study that assessed the relationships between quadriceps RTD and hop performance at 3 and 6 months after ACLR found a similar variance explained (R 2 ~0.4) when both RTD and PT were included in the model.…”

“…Compared with previous studies, we detected stronger associations between RTD and movement mechanics in individuals after ACLR. 19,26,35 Possible explanations for this discrepancy include variations in the methods used to calculate RTD (eg, RTD 20%-80% vs 0-100 ms from onset), time frames assessed postoperatively, the task performed (eg, running vs single-leg hop for distance), and/or the biomechanical variables of interest. During jumping tasks, RTD LSI accounted for only 21% of the variance in knee extensor moment symmetry at initial contact during the landing phase of a double-leg drop jump, but was not a significant predictor during the single-leg drop jump in a cross-sectional study (mean, 20.1 ± 9.1 months after ACLR; only female athletes).…”

“…In athletes after ACLR, better quadriceps RTD has generally been found to be weakly associated with better self-reported knee function, 10,18 walking ground-reaction forces (GRFs), 5 vertical and crossover hop performance, 26,41 and running and jumping kinetics. 19,35 However, most of these studies have been limited to cross-sectional designs with relatively small samples, and often with patients who are years removed from surgery, which may confound the influence that RTD has on movement biomechanics. As the majority of athletes return to sport at or before 1 year after surgery, 23 a longitudinal cohort beginning earlier after surgery is needed to determine the influence that quadriceps strength and RTD have on restoration of running mechanics in athletes after ACLR.…”

Jumping into recovery: A systematic review and meta‐analysis of discriminatory and responsive force plate parameters in individuals following anterior cruciate ligament reconstruction during countermovement and drop jumps

“…Out of the four parameters identified (eccentric deceleration impulse, concentric impulse, landing impulse and jump height) only the eccentric deceleration impulse significantly decreased between 6 and 9 months post-ACLR [13]. [32,39,51,55], with one study not reporting participants' sex [37]. Amongst the five studies, eleven unique parameters were identified.…”

“…No other kinetic parameters were reported [33]. [8,9,17,19,22,31,32,41,42,46,48,53,61,63,64]. Two studies did not report the participants' sex [19,41].…”