Landing Mechanics between Noninjured Women and Women with Anterior Cruciate Ligament Reconstruction during 2 Jump Tasks

Abstract

Background-Women with anterior cruciate ligament reconstruction have different neuromuscular strategies than noninjured women during functional tasks after ligament reconstruction and rehabilitation.

Greater muscle co‐contraction results in increased tibiofemoral compressive forces in females who have undergone anterior cruciate ligament reconstruction

“…Our results also would appear to support previous assertions that participation in sport following ACLR may be a risk factor with respect to knee OA development. 26 The increased muscle co-contraction observed in our ACLR subjects is consistent with the findings of Ortiz et al 6 and Vairo et al 7 who also reported greater cocontraction in persons post-ACLR. The increased CCI in the ACLR group was mainly the result of increased hamstring muscle activation (Table 3).…”

“…Increased hamstring muscle activation in persons post-ACLR has been hypothesized as a protective mechanism to decrease the anterior shear loads on the knee. 6,7 This premise was supported by our findings that the ACLR group on average had a similar peak anterior tibial shear force but a significantly greater posterior shear force generated from the hamstring muscles when compared to the control group (Tables 2 and 3).…”

“…[5][6][7] While this muscle recruitment strategy in persons post-ACLR is hypothesized to increase joint stability and decrease the anterior shear loads at the knee by providing a posterior shear force from the hamstring muscles, 6,7 the strategy of increased muscle co-contraction has been shown to increase the tibiofemoral compressive force in a simulated ACL-deficient knee model. 8 As such, it is plausible that the increased muscle co-contraction utilized by individuals who have undergone ACLR also may contribute to increased compressive force of the tibiofemoral joint.…”

Mapping current research trends on neuromuscular risk factors of non-contact ACL injury

“…One study demonstrated co-contraction ratios between normalised hamstring and quadriceps activations that were significantly closer to 1 in the ACL-R group during drop jumps, and greater gluteus maximus (Gmax) and rectus femoris (RF) activations (Ortiz, et al, 2008). Another study from the same research group showed that neuromuscular recruitment strategies during two side hopping tasks in ACL-R females did not differ from healthy controls (Ortiz, et al, 2011).…”

“…Two case-control studies described differences in muscular activation patterns between ACL-R and healthy controls (Ortiz, et al, 2008;Ortiz, Olson, Trudelle-Jackson, Rosario, & Venegas, 2011). One study demonstrated co-contraction ratios between normalised hamstring and quadriceps activations that were significantly closer to 1 in the ACL-R group during drop jumps, and greater gluteus maximus (Gmax) and rectus femoris (RF) activations (Ortiz, et al, 2008).…”