Lower-Extremity Compensations Following Anterior Cruciate Ligament Reconstruction

Abstract

Background and Purpose. Several studies have demonstrated that patients with knee injury scored within a normal range during one-legged hop tests yet showed quadriceps femoris muscle weakness with non–weight-bearing isokinetic testing. This study evaluated lower-extremity kinetics while subjects performed a single-leg vertical jump (VJ) and a lateral step-up (LSU) in an attempt to explain this phenomenon. Subjects and Methods. Using a motion analysis and force platform system, hip, knee, and ankle extension moments of 20 subjects with anterior cruciate ligament (ACL) reconstructions and 20 matched subjects were measured while they performed an LSU and a VJ. Results. An analysis of variance revealed that the knee extension moment of the ACL-reconstructed extremity was lower than that of the uninjured and matched extremities during the LSU, VJ take-off, and VJ landing. However, there was no difference in summated extension moment (hip + knee + ankle) among extremities during the LSU and VJ take-off. The summated extension moment of the ACL-reconstructed extremity during VJ landing was less than that of the uninvolved and matched extremities. Conclusions and Discussion. These results suggest that the hip or ankle extensors may compensate for the knee extension moment deficit. The decrease in summated extension moment in the ACL-reconstructed extremity during VJ landing represents inadequate attenuation of landing forces, which may expose the skeleton and joint structures to injury.

Asymmetries in joint work during multi‐joint movement after anterior cruciate ligament reconstruction: A pilot study

“…The analysis of W Total leads to determine the clinical parameters (hip and ankle joint ROM) responsible of the greater asymmetry of the TVD during vertical jumping in ACL-R subjects. To our knowledge, this study is the first one to analyze mechanical joint work during single-leg vertical jump after ACL-R. Our findings are consistent with several studies that describe asymmetries in subjects after ACL-R (Ernst et al, 2000;Gokeler et al, 2010;Orishimo et al, 2010;Paterno et al, 2010;Webster & Gribble, 2010;Castanharo et al, 2011;Myer et al, 2011;Xergia et al, 2013).…”

Lower limb asymmetry in mechanical muscle function: A comparison between ski racers with and without ACL reconstruction

“…The main finding of our study was the presence of a significantly greater CMJ and SJ phase-specific kinetic impulse AI in top-level ski racers with a history of ACL-R compared with uninjured ability-matched ski racers that remained despite a full return to activity. The finding of elevated functional asymmetry conforms to findings in non-athletic populations where ACLdeficient and ACL-R subjects exhibit elevated bilateral asymmetry during multi-joint lower body movements such as jumping and squatting (Ernst et al, 2000;Salem et al, 2003;Paterno et al, 2007;Castanharo et al, 2011;Holsgaard-Larsen et al, 2014) even up to 2 years postsurgery (Paterno et al, 2007;Castanharo et al, 2011).…”

“…At the return to sport phase, objective and sport-specific neuromuscular screening including functional testing is important to ensure athlete readiness and safety, and that pre-injury functional ability is restored (Myer et al, 2006). Evaluating subjects even up to 2 years post ACL-R is important due to the potential for prolonged deficits in function (Ernst et al, 2000;Paterno et al, 2007;Castanharo et al, 2011). Due to the high ACL re-injury rates in elite ski racing and the large physical demands, return to sport (i.e., return to snow) screening is important for ski racers following ACL-R. Neuromuscular testing and functional tests should also be easily administered within a high performance sport environment.…”

Whole‐body biomechanical differences between limbs exist 9 months after ACL reconstruction across jump/landing tasks

“…Similar findings have been reported in knee extension moments and vertical ground reaction forces during DLDJ testing 9 months after ACLR, with hip and ankle variables compensating for the knee. 45 Knee extension moment deficits during SLHD have been reported previously 6 months post-ACLR, but there was no between-limb difference for knee extension moment for the single-leg tests in this study though the COM was moved closer to the knee in the sagittal plane in them all. This may have been accomplished through trunk, pelvis or hip flexion or maintaining a more extended knee position, as seen in the SLHD, thus reducing the demand on the knee extensors by shortening the extensor moment arm.…”