The effect of weightbearing and external loading on anterior cruciate ligament strain

Fleming, Braden C.; Renström, Per; Beynnon, Bruce D.; Engström, Birgitta; Peura, Glenn D.; Badger, Gary J.; Johnson, Robert J.

doi:10.1016/s0021-9290(00)00154-8

Cited by 332 publications

(307 citation statements)

References 25 publications

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“…Secondly, in this study we did not evaluate the ACL graft forces under weight-bearing conditions. It has been reported that external torque under weight-bearing conditions may have a greater effect on the ACL strain than under non-weight-bearing conditions [30,31]. However, we believe that our results represent a conservative estimate of the elevated forces in the PC under external tibial torque and these forces may further increase under weight-bearing or combined loading conditions.…”

Section: Discussionmentioning

confidence: 62%

The effect of isolated popliteus tendon complex injury on graft force in anterior cruciate ligament reconstructed knees

Gadikota

Seon

et al. 2010

International Orthopaedics (SICOT)

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Failure to diagnose injury to the posterolateral structures has been found to increase the forces experienced by the anterior cruciate ligament (ACL) and ACL grafts which may cause their subsequent failure. An isolated injury to the popliteus complex (PC) consisting of the popliteus tendon and popliteofibular ligament is not uncommon. Therefore, the purpose of this study was to discover if an isolated injury to the PC can significantly affect the forces experienced by the ACL graft under external loading conditions. We hypothesised that, under external tibial torque, the ACL graft will experience a significant increase in force, in knees with PC injury compared to the intact PC condition. Under varus tibial torque (10 N m), we observed minimal changes in the varus tibial rotation due to isolated sectioning of the PC in an ACL reconstructed knee (P> 0.05). Consequently, no significant increase in the ACL graft force was observed under varus tibial torque. In contrast, sectioning the PC resulted in a significant increase in the external tibial rotation compared to the intact PC knee condition under the external rotational tibial torque (5 N m) at all flexion angles (P<0.05). These changes in kinematics under external tibial torque were manifested as elevated ACL graft forces at all selected flexion angles (P<0.05). Prompt diagnosis of isolated PC injury and its treatment are warranted to prevent potential failure of ACL reconstruction.

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Section: Discussionmentioning

confidence: 62%

The effect of isolated popliteus tendon complex injury on graft force in anterior cruciate ligament reconstructed knees

Gadikota

Seon

et al. 2010

International Orthopaedics (SICOT)

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“…ACL loading decreases as knee flexion angle increases, especially when the knee flexion angle is less than 30° [29]. At a given knee flexion angle, ACL loading decreases as the anterior shear force applied on the proximal end of the tibia decreases [17,38]. The relationship between ACL loading and knee flexion angle is attributable to the relationships between the patellar tendon-tibial shaft angle and knee flexion angle and between the ACL elevation angle and knee flexion angle (Fig.…”

Section: Discussionmentioning

confidence: 99%

Effects of a Knee Extension Constraint Brace on Lower Extremity Movements after ACL Reconstruction

Stanley

Creighton

Gross

et al. 2011

Clinical Orthopaedics &Amp; Related Research

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Background Patients have high reinjury rates after ACL reconstruction. Small knee flexion angles and large peak posterior ground reaction forces in landing tasks increase ACL loading. Questions/purposes We determined the effects of a knee extension constraint brace on knee flexion angle, peak posterior ground reaction force, and movement speed in functional activities of patients after ACL reconstruction. Patients and Methods Six male and six female patients 3.5 to 6.5 months after ACL reconstruction participated in the study. Three-dimensional videographic and force plate data were collected while patients performed level walking, jogging, and stair descent wearing a knee extension constraint brace, wearing a nonconstraint brace, and not wearing a knee brace. Knee flexion angle at initial foot contact with the ground, peak posterior ground reaction force, and movement speed were compared across brace conditions and between genders. Results Wearing the knee extension constraint brace increased the knee flexion angle at initial foot contact for each activity when compared with the other two brace conditions. Wearing the knee extension constraint brace also decreased peak posterior ground reaction force during walking but not during jogging and stair descent. Conclusions Although the knee extension constraint brace did not consistently reduce the peak posterior ground reaction force in all functional activities, it consistently increased knee flexion angle and should reduce ACL loading as suggested by previous studies. These results suggest the knee extension constraint brace has potential as a rehabilitation tool to alter lower extremity movement patterns of patients after ACL reconstruction to address high reinjury rates. Level of Evidence Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

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“…In turn, an anterior shear force would be applied to the tibia relative to the femur. It is well known that an anterior shear force causes the tibia to move anterior relative to the femur (Butler et al, 1980), and we have shown that an anterior shear force applied to the tibia will strain the knee in the weightbearing and non-weight bearing knee (Fleming et al, 2001a). Therefore, we are confident that the perturbation used in this study will elicit a response in the ACL, which may influence the knee musculature.…”

Section: Discussionmentioning

confidence: 61%

“…These data are necessary to establish if the APR is altered with an intra-articular injection of local anesthesia, or when an effusion is present. If no changes are observed then it will be possible to measure ACL strains when dynamic perturbations are applied to the limb in vivo (Fleming et al, 2001a, Beynnon andFleming, 1998).…”

Section: Introductionmentioning

confidence: 99%

Intra-articular anesthesia and knee muscle response

Oksendahl

Fleming

Blanpied

et al. 2007

Clinical Biomechanics

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Background-Many receptors located within the intra-articular knee structures contribute to the neuromuscular responses of the knee. The purpose was to compare the automatic postural response induced by a perturbation at the foot before and after an intra-articular injection of a local anesthetic (bupivicaine), after a saline (sham) injection, and after no intra-articular injection (control) in the knee.Methods-Muscle onset latencies and automatic response magnitudes for the vastus medialis, vastus lateralis, biceps femoris, medial hamstrings, tibialis anterior, and gastrocnemius were measured using EMG when anteriorly directed perturbations were applied to the feet of 30 subjects. All subjects then received a lidocaine skin injection followed by: an intra-articular bupivicaine injection (treatment group); an intra-articular saline injection (sham group); or no injection (control group), depending on their randomized group assignment. The perturbation tests were then repeated.Findings-Muscle onset latencies and automatic response magnitudes did not change as a result of the intra-articular injections. Latencies were significantly greater for the vastus medialis and vastus lateralis when compared to the medial hamstrings, biceps femoris and tibialis anterior (p<0.001). Automatic response magnitudes for the tibialis anterior were significantly greater than those of the hamstrings, which were greater than those of the quadriceps (p<0.001).Interpretation-There were no differences in muscle response when anteriorly directed perturbations were applied to the foot with or without an injection of local anesthetic in the knee. Intra-articular receptors were either unaffected by the anesthetic or the extra-articular receptors or receptors of the other joints were able to compensate for their loss.

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The effect of weightbearing and external loading on anterior cruciate ligament strain

Cited by 332 publications

References 25 publications

The effect of isolated popliteus tendon complex injury on graft force in anterior cruciate ligament reconstructed knees

The effect of isolated popliteus tendon complex injury on graft force in anterior cruciate ligament reconstructed knees

Effects of a Knee Extension Constraint Brace on Lower Extremity Movements after ACL Reconstruction

Intra-articular anesthesia and knee muscle response

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