Limb dominance influences energy absorption contribution (EAC) during landing after anterior cruciate ligament reconstruction

Relationship Between Quadriceps Strength and Knee Joint Power During Jumping After ACLR

Background

Knee joint power is significantly impaired during the propulsive phase of jumping after anterior cruciate ligament reconstruction (ACLR); however, it is currently unknown how quadriceps strength influences knee joint power.

Purpose

To (1) evaluate the relationship between quadriceps strength, joint power, and the percentage contribution of the hip, knee, and ankle joints to total limb power during the propulsive phase of jumping and (2) establish a quadriceps strength cutoff value for maximizing the likelihood of having knee joint power characteristics similar to healthy participants.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 75 participants were included in this study-40 patients who underwent ACLR 6 months before (18 females; mean age, 19.3 ± 5.7 years) and 35 healthy controls (HC) (20 females; mean age, 21.5 ± 4.5 years). Participants performed a drop vertical jump and underwent isometric quadriceps strength testing. The peak joint power was calculated as the product of the internal joint moment and joint angular velocity. Pearson product-moment correlations were used to assess the relationship between quadriceps strength and knee joint power. Paired samples t tests were used to quantify differences between limbs. Receiver operating characteristic (ROC) curve analysis was used to determine a quadriceps strength cutoff.

Results

The involved limbs of the ACLR cohort (INV) had significantly lower peak knee joint power and percentage contribution from the knee joint during jumping compared with the uninvolved limbs (NON) and limbs of the controls (INV, 2.5 ± 1.2 W/kg; NON, 4.4 ± 1.5 W/kg; HC, 4.3 ± 1.7 W/kg [P < .0001]). Quadriceps strength was associated with knee joint power in involved limbs and limbs of controls (INV, r = 0.50; HC, r = 0.60). A quadriceps strength cutoff value of 2.07 N·m/kg had an area under the ROC curve of 0.842, indicating good predictive accuracy.

Conclusion

Athletes at 6 months after ACLR demonstrated knee-avoidant jumping mechanics and had significant reductions in knee joint power on the involved limb. A quadriceps strength cutoff value of 2.07 N·m/kg can help predict which athletes will display knee joint power characteristics similar to those of healthy controls.

Effects of Limb Dominance on Patellofemoral Joint Loading During Gait at 12 Weeks After Anterior Cruciate Ligament Reconstruction

Background:

Patellofemoral joint complications have commonly been reported in long-term outcome studies for anterior cruciate ligament reconstruction (ACLR); however, the biomechanics in the early phases of rehabilitation that could be associated with the development of these abnormalities is unclear. Limb dominance may affect the biomechanics of the knee joint in patients after ACLR.

Purpose:

To compare knee joint loading between surgical and nonsurgical limbs at 12 weeks postoperatively in patients who underwent ACLR on either their dominant limb (ACL-D) or nondominant limb (ACL-ND).

Study Design:

Controlled laboratory study.

Methods:

Included were 54 patients (32 ACL-D and 22 ACL-ND). Peak and integrated patellofemoral joint stress (PFJS), peak patellofemoral joint reaction force (PFJRF), and peak knee extension moment (KEM) were assessed during the stance phase of gait while participants walked on a 10-m runway at a self-selected speed.

Results:

The surgical limb of the ACL-D group had significantly decreased peak PFJS (P < .001), integrated PFJS (P < .001), peak PFJRF (P < .001), and peak KEM (P < .001) compared to the nonsurgical limb. The surgical limb of the ACL-ND group demonstrated significantly increased peak PFJS (P = .001), integrated PFJS (P = .023), peak PFJRF (P < .001), and peak KEM (P = .001) compared to the nonsurgical limb. For the surgical limb, the ACL-ND group demonstrated significantly greater peak PFJS (P < .001), peak PFJRF (P < .001) , (PFJRF [P<.001]) and peak KEM (P < .001) than the ACL-D group. For the nonsurgical limb, the ACL-D group demonstrated greater peak PFJS (P < .001), integrated PFJS (P = .023), peak PFJRF (P = .003), and peak KEM (P < .001) than the ACL-ND group.

Conclusion:

Significantly larger knee joint loading on the surgical limb of the ACL-ND group and smaller knee joint loading on the surgical limb of the ACL-D group were observed compared to the contralateral nonsurgical limb, which suggests that limb dominance has a key role in loading at the knee joint during gait.

Clinical Relevance:

Altered knee joint loading during gait at 12 weeks after ACLR may lead to the development of patellofemoral joint abnormalities.

Are Elite Collegiate Female Athletes PRIME for a Safe Return to Sport after ACLR? An Investigation of Physical Readiness and Integrated Movement Efficiency (PRIME)

Background

Elite female athletes who successfully return to sport after anterior cruciate ligament reconstruction (ACLR) represent a high-risk group for secondary injury. Little is known about how the functional profile of these athletes compares to their teammates who have not sustained ACL injuries.

Purpose

To compare elite collegiate female athletes who were able to successfully return to sport for at least one season following ACLR to their teammates with no history of ACLR with regard to self-reported knee function, kinetics, and kinematics during a double limb jump-landing task.

Study Design

Cross-Sectional Study.

Level of Evidence

Level 3.

Methods

Eighty-two female collegiate athletes (17 ACLR, 65 control) completed the knee-specific SANE (single assessment numeric evaluation) and three trials of a jump-landing task prior to their competitive season. vGRF data on each limb and the LESS (Landing Error Scoring System) score were collected from the jump-landing task. Knee-SANE, vGRF data, and LESS scores were compared between groups. All athletes were monitored for the duration of their competitive season for ACL injuries.

Results

Athletes after ACLR reported worse knee-specific function. Based on vGRF data, they unloaded their involved limb during the impact phase of the landing, and they were more asymmetrical between limbs during the propulsion phase as compared to the control group. The ACLR group, however, had lower LESS scores, indicative of better movement quality. No athletes in either group sustained ACL injuries during the following season.

Conclusion

Despite reporting worse knee function and demonstrating worse kinetics, the ACLR group demonstrated better movement quality relative to their uninjured teammates. This functional profile may correspond to short-term successful outcomes following ACLR, given that no athletes sustained ACL injuries in the competition season following assessment.

Lower limb kinematics differ at the time of foot contact between successful and unsuccessful single limb landings following anterior cruciate ligament reconstruction

OBJECTIVES

To investigate differences in lower extremity kinematics at initial ground contact between successful and unsuccessful single limb landings following anterior cruciate ligament (ACL) reconstruction.

DESIGN

Observational study.

SETTING

Controlled laboratory environment.

PARTICIPANTS

22 male participants (aged 17-40 years) who had undergone unilateral ACL reconstruction attended a single test session.

MAIN OUTCOME MEASURES

Within-subjects comparisons was performed for pelvis, hip, knee and ankle kinematics using paired t-tests.

RESULTS

When unsuccessful at landing on the ACL reconstructed limb, participants had significantly increased knee flexion (P = 0.04) and reduced ankle plantarflexion (P = 0.03) compared to their successful landings. In contrast, when unsuccessful at landing on the unaffected limb, participants had significantly increased pelvic contralateral hitch (P < 0.01) and increased hip abduction (P < 0.01) compared to successful landings.

CONCLUSION

Body position at the time of initial contact was different for landings that were successful compared to landings that were unsuccessful. These differences were limb-specific: altered position in sagittal plane preceded unsuccessful landings on the reconstructed limb whereas altered position in the coronal plane body position that preceded unsuccessful landings on the unaffected limb. These findings suggest that limb specific landing strategies may be required to improve athletes' performance following ACL reconstruction.

LEVEL OF EVIDENCE

IV.