A Musculoskeletal Modeling Approach for Estimating Anterior Cruciate Ligament Strains and Knee Anterior–Posterior Shear Forces in Stop-Jumps Performed by Young Recreational Female Athletes

The central goal of this study was to contribute to the advancements being made in determining the underlying causes of anterior cruciate ligament (ACL) injuries. ACL injuries are frequently incurred by recreational and professional young female athletes during non-contact impact activities in sports like volleyball and basketball. This musculoskeletal-neuromuscular study investigated stop-jumps and factors related to ACL injury like knee valgus and internal–external moment loads, knee anterior–posterior (AP) shear forces, ACL strains and internal forces. Motion capture data was obtained from the landing phase of stop-jumps performed by eleven young recreational female athletes and electromyography (EMG) data collected from quadriceps, hamstring and gastrocnimius muscles which were then compared to numerically estimated activations. Numerical simulation tools used were Inverse Kinematics, Computed Muscle Control and Forward Dynamics and the knee modeled as a six degree of freedom joint. Results showed averaged peak strains of 12.2 ± 4.1% in the right and 11.9 ± 3.0% in the left ACL. Averaged peak knee AP shear forces were 482.3 ± 65.7 N for the right and 430.0 ± 52.4 N for the left knees, approximately equal to 0.7–0.8 times body weight across both knees. A lack of symmetry was observed between the knees for valgus angles (p < 0.04), valgus moments (p < 0.001) and muscle activations (p < 0.001), all of which can be detrimental to ACL stability during impact activities. Comparisons between recorded EMG data and estimated muscle activations show the relation between electrical signal and muscle depolarization. In summary, this study outlines a musculoskeletal simulation approach that provides numerical estimations for a number of variables associated with ACL injuries in female athletes performing stop-jumps.     

Mechanisms of noncontact anterior cruciate ligament injury

OBJECTIVE: To examine and summarize previous retrospective and observational studies assessing noncontact anterior cruciate ligament (ACL) injury mechanisms and to examine such reported ACL injury mechanisms based on ACL loading patterns due to knee loadings reported in in vivo, in vitro, and computer simulation studies. DATA SOURCES: We searched MEDLINE from 1950 through 2007 using the key words anterior cruciate ligament + injury + mechanisms; anterior cruciate ligament + injury + mechanisms + retrospective; and anterior cruciate ligament + injury + mechanisms + video analysis. STUDY SELECTION: We selected retrospective studies and observational studies that specifically examined the noncontact ACL injury mechanisms (n = 7) and assessed ACL loading patterns in vivo, in vitro, and using computer simulations (n = 33). DATA EXTRACTION: The motion patterns reported as noncontact ACL injury mechanisms in retrospective and observational studies were assessed and critically compared with ACL loading patterns measured during applied external or internal (or both) forces or moments to the knee. DATA SYNTHESIS: Noncontact ACL injuries are likely to happen during deceleration and acceleration motions with excessive quadriceps contraction and reduced hamstrings co-contraction at or near full knee extension. Higher ACL loading during the application of a quadriceps force when combined with a knee internal rotation moment compared with an external rotation moment was noted. The ACL loading was also higher when a valgus load was combined with internal rotation as compared with external rotation. However, because the combination of knee valgus and external rotation motions may lead to ACL impingement, these combined motions cannot be excluded from the noncontact ACL injury mechanisms. Further, excessive valgus knee loads applied during weight-bearing, decelerating activities also increased ACL loading. CONCLUSIONS: The findings from this review lend support to ACL injury prevention programs designed to prevent unopposed excessive quadriceps force and frontal-plane or transverse-plane (or both) moments to the knee and to encourage increased knee flexion angle during sudden deceleration and acceleration tasks.     

非预期条件下前交叉韧带重建术后运动员侧切动作下肢运动生物力学特征

目的 量化非预期条件下前交叉韧带重建(anterior cruciate ligament reconstruction, ACLR)术后运动员侧切动作中膝关节生物力学特征,探讨运动员前交叉韧带(anterior cruciate ligament, ACL)损伤潜在风险。 方法 应用红外运动捕捉系统和三维测力台同步采集 30 名 ACLR 男性运动员在预期和非预期条件下侧切动作中健侧、患侧下肢运动学和动力学数据。 应用双因素方差分析对关节角度、关节力矩、地面反作用力( ground reaction force, GRF)等测试指标进行统计分析。 结果 患侧肢体的膝关节屈曲角度、外翻力矩和屈曲力矩显著低于健侧肢体,内旋力矩和胫骨前剪切力显著高于健侧肢体。 与预期条件相比,非预期条件下膝关节屈曲角度、内旋力矩、胫骨前剪切力显著增加。 患侧肢体膝关节外旋角度在预期和非预期条件下均显著高于健侧,非预期条件下健侧肢体侧向 GRF 和前后 GRF 显著小于预期条件,患侧肢体侧向 GRF 显著高于预期条件。 结论 ACLR 运动员进行侧切动作时,相比于健侧,患侧表现出较小的膝关节屈曲角度,较大的膝关节内旋力矩和胫骨前剪切力的生物力学特征,可能存在较大的 ACL 潜在损伤风险;在非预期条件下,ACLR 运动员双侧下肢均表现出膝关节内旋力矩增大,侧向 GRF 增大和胫骨前剪切力增大的生物力学特征,提示 ACL 潜在损伤风险不仅限于患侧,健侧下肢也应加强侧切动作中 ACL 损伤预防。     

Gender differences in knee kinematics and muscle activity during single limb drop landing

The likelihood of sustaining an ACL injury in a noncontact situation is two to eight times greater for females than for males. However, the mechanism and risk factors of ACL injury are still unknown. We compared knee kinematics as well as electromyographic activity during landing between male and female athletes. Eighteen male athletes and nineteen female athletes participated in the experiment. The angular displacements of flexion/extension, valgus/varus, and internal/external tibial rotation, as well as the translational displacements of anterior/posterior tibial translation during single limb drop landing were calculated. Simultaneous electromyographical activity of the rectus femoris (RF) and hamstrings (Ham) was taken. During landing, internal tibial rotation of the females was significantly larger than that of the males, while differences were not observed in flexion, varus, valgus, and anterior tibial translation. Hamstrings/quadriceps ratio (HQR) for the 50 ms time period before foot contact was greater in males than in females. The mechanism of noncontact ACL injury during a single limb drop landing would be internal tibial rotation combined with valgus rotation of the knee. Increased internal tibial rotation combined with greater quadriceps activity and a low HQR could be one reason female athletes have a higher incidence of noncontact ACL injuries.     

Knee Joint Kinematics and Kinetics During a Lateral False-Step Maneuver

Context:

Cutting maneuvers have been implicated as a mechanism of noncontact anterior cruciate ligament (ACL) injuries in collegiate female basketball players.

Objective:

To investigate knee kinematics and kinetics during running when the width of a single step, relative to the path of travel, was manipulated, a lateral false-step maneuver.

Design:

Crossover design.

Setting:

University biomechanics laboratory.

Patients or Other Participants:

Thirteen female collegiate basketball athletes (age  =  19.7 ± 1.1 years, height  =  172.3 ± 8.3 cm, mass  =  71.8 ± 8.7 kg).

Intervention(s):

Three conditions: normal straight-ahead running, lateral false step of width 20% of body height, and lateral false step of width 35% of body height.

Main Outcome Measure(s):

Peak angles and internal moments for knee flexion, extension, abduction, adduction, internal rotation, and external rotation.

Results:

Differences were noted among conditions in peak knee angles (flexion [P < .01], extension [P  =  .02], abduction [P < .01], and internal rotation [P < .01]) and peak internal knee moments (abduction [P < .01], adduction [P < .01], and internal rotation [P  =  .03]). The lateral false step of width 35% of body height was associated with larger peak flexion, abduction, and internal rotation angles and larger peak abduction, adduction, and internal rotation moments than normal running. Peak flexion and internal rotation angles were also larger for the lateral false step of width 20% of body height than for normal running, whereas peak extension angle was smaller. Peak internal rotation angle increased progressively with increasing step width.

Conclusions:

Performing a lateral false-step maneuver resulted in changes in knee kinematics and kinetics compared with normal running. The differences observed for lateral false steps were consistent with proposed mechanisms of ACL loading, suggesting that lateral false steps represent a hitherto neglected mechanism of noncontact ACL injury.     

Biomechanical and performance differences between female soccer athletes in National Collegiate Athletic Association Divisions I and III

CONTEXT: The recent increase in women's varsity soccer participation has been accompanied by a lower extremity injury rate that is 2 to 6 times that of their male counterparts. OBJECTIVE: To define the differences between lower extremity biomechanics (knee abduction and knee flexion measures) and performance (maximal vertical jump height) between National Collegiate Athletic Association Division I and III female soccer athletes during a drop vertical jump. DESIGN: Mixed 2 x 2 design. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Thirty-four female collegiate soccer players (Division I: n = 19; Division III: n = 15) participated in the study. The groups were similar in height and mass. INTERVENTION(S): Each subject performed a maximal vertical jump, followed by 3 drop vertical jumps. MAIN OUTCOME MEASURE(S): Kinematics (knee abduction and flexion angles) and kinetics (knee abduction and flexion moments) were measured with a motion analysis system and 2 force platforms during the drop vertical jumps. RESULTS: Knee abduction angular range of motion and knee abduction external moments were not different between groups (P > .05). However, Division I athletes demonstrated decreased knee flexion range of motion (P = .038) and greater peak external knee flexion moment (P = .009) compared with Division III athletes. Division I athletes demonstrated increased vertical jump height compared with Division III (P = .008). CONCLUSIONS: Division I athletes demonstrated different sagittal-plane mechanics than Division III athletes, which may facilitate improved performance. The similarities in anterior cruciate ligament injury risk factors (knee abduction torques and angles) may correlate with the consistent incidence of anterior cruciate ligament injury across divisions.     

Knee rotation associated with dynamic knee valgus and toe direction

BackgroundDynamic knee valgus contributes to injuries of the anterior cruciate ligament (ACL). However, it is unclear how the knee rotates during dynamic knee valgus. Knee rotation significantly affects ACL strain. To understand knee rotation during dynamic knee valgus should help the clinician evaluate dynamic alignment. The purpose of this study was to determine how the knee rotates during dynamic knee valgus and whether the knee rotation is affected by toe direction (foot rotation).MethodsSixteen females performed dynamic knee valgus in three toe directions (neutral, toe-out, and toe-in) while maintaining the knee flexion angle at 30°. The knee rotation angle was evaluated using a 7-camera motion analysis system. Knee rotation was compared between the start position and the dynamic knee valgus position, as well as among the three toe directions, using repeated measures ANOVA models.ResultsThe knee significantly rotated externally in the dynamic knee valgus position compared with the start position in two toe directions (neutral and toe-out). A similar tendency was observed with the toe-in condition. Toe direction significantly affected the knee rotation angle. For toe-out and toe-in conditions, external and internal shifts of knee rotation compared with neutral were observed.ConclusionsThe knee rotates externally during dynamic knee valgus, and the knee rotation is affected by toe direction.Clinical RelevanceBecause of knee abduction and external rotation, the ACL may impinge on the femoral condyle in the case of dynamic valgus, especially in the toe-out position.     

Sidestep cutting maneuvers in female basketball players: Stop phase poses greater risk for anterior cruciate ligament injury

BackgroundMany non-contact anterior cruciate ligament (ACL) injuries in female basketball players occur during sidestep cutting. The objective of this study was to identify the phases of a sidestep cutting maneuver that place athletes at a greater risk for ACL injuries.MethodsTen healthy female collegiate basketball athletes were asked to perform sidestep cutting movements; the knee flexion and valgus angles as well as the electromyographic activity of the vastus lateral, vastus medial, biceps femoris, and semimembranosus muscles of the non-dominant leg were analyzed during the maneuver.ResultsThe mean knee valgus angle peak tended to be greater during the stop phase than during the side-movement phase. The quadriceps activation during the stop phase was significantly higher than that during the side-movement phase. Moreover, the ratio of hamstring to quadriceps muscle activation during the stop phase was significantly lower than that during the side-movement phase, as assessed by surface electromyography.ConclusionFemale basketball athletes have a higher risk for ACL injury during the stop phase than during the side-movement phase of the sidestep cutting maneuver.Level of evidenceLevel III.     

The Effects of a Valgus Collapse Knee Position on In Vivo ACL Elongation

There are conflicting data regarding what motions increase ACL injury risk. More specifically, the mechanical role of valgus collapse positions during ACL injury remains controversial. Our objective was to evaluate ACL elongation in a model that mimics knee movements thought to occur during ACL injury. Eight healthy male subjects were imaged using MR and biplanar fluoroscopy to measure the in vivo elongation of the ACL and its functional bundles during three static knee positions: full extension, 30° of flexion, and a position intended to mimic a valgus collapse position described in the literature. For this study, the valgus collapse position consisted of 30° of knee flexion, internal rotation of the hip, and 10° of external tibial rotation. ACL length decreased significantly from full extension (30.2?±?2.6?mm) to 30° of flexion (27.1?±?2.2?mm). ACL length further decreased in the valgus collapse position (25.6?±?2.4?mm). Both functional bundles of the ACL followed similar trends with regards to decreases in length in each of the three positions. Since strain would follow patterns of ACL length, landing on an extended knee may be a more relevant risk factor for ACL injuries than the valgus collapse position in males. Future studies should evaluate the effects of dynamic motion patterns on in vivo ACL strains.     

Anterior cruciate ligament repair versus reconstruction: A kinematic analysis

BackgroundThe purpose of this study was to compare the biomechanical properties of an anterior cruciate ligament (ACL) anatomic repair of a true femoral avulsion to an anatomic ACL reconstruction. It was hypothesized that the ACL repair and ACL reconstruction would have comparable biomechanical behavior when compared to the native knee.MethodsTen paired fresh-frozen cadaveric knees (n = 20) were used to investigate knee kinematics when an anterior drawer force, varus, valgus, internal, and external rotational moment were applied at 0, 15, 30, 45, 60, and 90 degrees of flexion. Displacement and rotation were recorded in the following conditions: ACL-intact, ACL-deficient, and ACL-repaired vs reconstructed.ResultsSectioning of the ACL significantly increased anterior tibial translation (0°, 15°, 30° and 45°) compared to the intact state. The mean anterior displacement difference from intact was lower in the ACL-repaired knees compared to reconstructed knees at 30° and 90°. There were no significant differences between conditions in varus, valgus, internal, or external rotations.ConclusionACL repair and ACL reconstruction procedures restored knee anterior tibial translation in matched paired specimens. There were no differences in valgus, varus, internal, or external rotation. Although, ACL-repaired knees (avulsion model) demonstrated less anterior tibial translation when compared to ACL-reconstructed knees, this difference was less than one millimeter. Based on the findings of this study, repair and reconstruction procedures both restored anterior tibial translation in matched-pair specimens. This suggests that the initial functionality of both techniques is similar and that further clinical studies are needed to compare the long-term stability.     

The combined impact of a perceptual–cognitive task and neuromuscular fatigue on knee biomechanics during landing

Background

A large majority of anterior cruciate ligament (ACL) injuries are non-contact, most often occurring during a landing or change of direction. Recent research indicates that cognitive factors may be involved in non-contact ACL injuries. The aim of this study was to determine if a game-situation perceptual–cognitive load leads to altered landing kinematics in physically fatigued female athletes.

Effect of wearing a knee brace or sleeve on the knee joint and anterior cruciate ligament force during drop jumps: A clinical intervention study

Background

Knee braces are considered to be extremely useful tools in reducing the shear force of knee joints for non-contact anterior cruciate ligament (ACL) injury prevention. However, the effectiveness of sports knee braces and sleeves remains to be identified. Therefore, the purpose of this study was to evaluate the effectiveness of wearing commercialized sports knee braces and sleeves on knee kinematics, kinetics, and ACL force during drop jumps using musculoskeletal modeling analysis.

Effects of foot rotation positions on knee valgus during single-leg drop landing: Implications for ACL injury risk reduction

Background

Non-contact anterior cruciate ligament (ACL) injuries commonly occur when athletes land in high risk positions such as knee valgus. The position of the foot at landing may influence the transmission of forces from the ankle to the knee. Using an experimental approach to manipulate foot rotation positions, this study aimed to provide new insights on how knee valgus during single-leg landing may be influenced by foot positions.

The effect of anterolateral ligament reconstruction on knee constraint: A computer model-based simulation study

BackgroundTo determine the influence of anterolateral ligament reconstruction (ALLR) on knee constraint through the analysis of knee abduction (valgus) moment when the knee is subjected to external translational (anterior) or rotational (internal) loads.MethodsA knee computer model simulated from a three-dimensional computed tomography scan of healthy male was implemented for this study. Three groups were designed: (1) intact knee, (2) combined Anterior Cruciate Ligament (ACL) and Antero-Lateral Complex (ALC) deficient knee, and (3) combined ACL and Antero- lateral Ligament (ALL) reconstructed knee. The reconstructed knee group was subdivided into four groups according to attachment of reconstructed anterolateral ligament to the femoral epicondyle. Each group of simulated knees was placed at 0°, 10°, 20°, 30°, 40° and 50° of knee flexion. For each position an external anterior (drawer) 90-N force or a five-newton meter internal rotation moment was applied to the tibia. The interaction effect between the group of knees and knee flexion angle (0–50°) on knee kinematics and knee abduction moment under external loads was tested.ResultsWhen reconstructed knees were subjected to a 90-N anterior force or a five-newton meter internal rotation moment there was significant reduction in anterior translation and internal rotation compared with deficient knees. Only the ALLR procedure using posterior and proximal femoral attachment sites for graft fixation combined with ACL reconstruction allowed similar mechanical behavior to that observed in the intact knee.ConclusionsCombined ACL and ALLR using a minimally invasive method in an anatomically reproducible manner prevents excessive anterior translation and internal rotation. Using postero-proximal femoral attachment tunnel for reconstruction of ALL does not produce overconstraint of the lateral tibiofemoral compartment.     

Is knee neuromuscular activity related to anterior cruciate ligament injury risk? A pilot study

Background

There is limited evidence on neuromuscular risk factors for anterior cruciate ligament (ACL) injuries, with most work mainly focusing on hamstrings and quadriceps muscle strength. This prospective pilot study explored if neuromuscular activation patterns of the quadriceps and hamstrings during a drop vertical jump influence ACL injury risk.

Biomechanical characteristics of the knee joint in female athletes during tasks associated with anterior cruciate ligament injury

This study was designed to compare biomechanical characteristics of the knee joint for several athletic tasks to elucidate their effects and to examine what tasks pose a risk for ACL injury.Three athletic tasks were performed by 24 female athletes: single-limb landing, plant and cutting, and both-limb jump landing. Angular displacements of flexion/extension, abduction/adduction, and external/internal tibial rotation were calculated. Angular excursion and the rate of excursion of abduction and internal tibial rotation were also calculated.During plant and cutting, from foot contact, subjects rotated the tibia more rapidly and to a greater degree toward internal tibial rotation. Moreover, excursion of knee abduction is greater than that during single-limb landing. During both-limb jump landing, the knee flexion at foot contact was greater than for either single-limb landing or plant and cutting; peak knee abduction was greater than for either single-limb landing or plant and cutting.In plant and cutting, the risk of ACL injury is increased by greater excursion and more rapid knee abduction than that which occurs in single-limb landing, in addition to greater internal tibial rotation. Although single-limb tasks apparently pose a greater risk for ACL injury than bilateral landings, both-limb landing with greater knee abduction might also risk ACL injury.     

直线前进变换为侧向跨步切入动作时的下肢生物力学变化

背景:侧向跨步切入动作是运动领域最常见的进攻技术,这显著增加了运动员膝关节受伤的风险,但目前相关侧向跨步动作的生物力学表现策略及下肢关节负荷特征并不十分清楚。目的:选择大学女子甲组篮球、足球运动员进行侧向跨步切入下肢动作策略,进行生物力学测试,并分析下肢关节的运动学及动力学参数,从而为运动员及教练员预防下肢伤害,尤其是膝关节十字韧带损伤提供重要参考。方法:选择某高校女子甲组足球及篮球各12名运动员作为研究对象,利用三维测力台及运动图像拍摄系统同步获取其侧向跨步切入动作的相关运动学及动力学参数,并运用SPSS 21.0分析软件对相关数据进行处理分析。该试验方案经天津体育学院伦理委员会批准。结果与结论:①足球运动员有较大的着地瞬间踝关节跖屈角度及髋关节外展角度、最大踝关节外翻角度、膝关节屈曲及内旋角度、膝关节屈曲及内旋角度变化量;②足球运动员有较大的踝关节外旋与髋关节内收力矩峰值,篮球运动员则有较大的踝关节跖屈力矩峰值;③篮球运动员有较小的前后分力制动第一及第二峰值、垂直分力第一峰值及较大的前后分力推蹬力峰值;④结果表明,跨步切入动作过程中,足球运动员习惯于前足着地方式进行急停,进而产生较高的地面反作用力,并增加膝关节屈曲角度进行缓冲,同时有较大的踝关节外翻角度及膝关节内旋角度,而篮球运动员在切入过程中膝关节屈曲角度较少,不利于下肢关节对地面反作用力的缓冲,并进而增加前十字韧带损伤风险。     

Effect of isolated hip abductor fatigue on single-leg landing mechanics and simulated ACL loading

BackgroundAltered movement biomechanics are a risk factor for ACL injury. While hip abductor weakness has been shown to negatively impact landing biomechanics, the role of this musculature and injury risk is not clear. The aim of this musculoskeletal simulation study was to determine the effect of hip abductor fatigue-induced weakness on ACL loading, force production of lower extremity muscles, and lower extremity biomechanics during single-leg landing.MethodsBiomechanical data from ten healthy adults were collected before and after a fatigue protocol and used to derive subject-specific estimates of muscle forces and ACL loading using a 5-degree of freedom (DOF) model.ResultsThere were no significant differences in knee joint angles and ACL loading between pre and post-fatigue. However, there were significant differences, due to fatigue, in lateral trunk flexion angle, total excursion of trunk, muscle forces, and joint moments.ConclusionAltered landing mechanics, due to hip abductor fatigue-induced weakness, may be associated with increased risk of ACL injury during single-leg landings. Clinical assessment or screening of ACL injury risk will benefit from subject-specific musculoskeletal models during dynamic movements. Future study considering the type of the fatigue protocols, cognitive loads, and various tasks is needed to further identify the effect of hip abductor weakness on lower extremity landing biomechanics.     

非接触性前交叉韧带损伤特点及机制的研究进展

前交叉韧带断裂是膝关节最常见运动损伤之一,大部分是非接触性原因造成的。理解前交叉韧带受力和损伤机制对预防和治疗损伤有重要意义。本文综述了国内外对前交叉韧带损伤特点及其受力和损伤机制的研究结果。研究表明,下肢矢状面的生物力学是前交叉韧带受力的主要影响因素,如较小的膝关节屈角,较大的地面反作用力,较大的股四头肌力。其中较大的地面反作用力引发较大的股四头肌力和胫骨近端向前的拉力从而增加前交叉韧带负荷。较小的膝关节角合并较大的髌韧带与胫骨夹角和前交叉韧带倾斜角会增大韧带负荷。交叉韧带并不是承受膝关节内、外翻和内旋     

Knee biomechanical factors associated with patellofemoral pain in recreational runners

BackgroundPatellofemoral pain (PFP) is a common injury among runners. Knee biomechanical factors associated with PFP, however, remain unclear. The purpose of this study was to determine possible associations between knee biomechanics and symptoms of PFP in recreational runners.MethodsFifteen male and 15 female recreational runners with PFP were enrolled as the PFP group, 30 matched runners without PFP were recruited as the control group. The PFP group was tested running with and without knee pain, while the control group had only one running test. Reflective marker coordinates and ground reaction force data were collected in each test. Knee kinematics and kinetics during running were reduced and compared between groups (PFP group without knee pain and control group) and between pain conditions (PFP group with knee pain and without knee pain), as well as between sexes.ResultsFemale and male participants with PFP had an increased peak knee valgus angle when running without pain compared to matched controls (P = 0.001), and to themselves when running with pain (P = 0.001). Male participants with PFP also had an increased peak knee flexion angle when running without pain compared to matched controls (P = 0.008), however did not decrease their peak knee flexion angle when running with pain (P = 0.245). No significant main effect of group or pain condition on any peak knee joint moment during running was detected (P ≥ 0.175).ConclusionsIncreased peak knee valgus angle during running appears to be a critical biomechanical factor associated with PFP in recreational runners, while decreasing knee valgus angle during running may be an adaptation to reduce symptoms of PFP. Increased peak knee flexion angle during running appears to be another biomechanical factor associated with PFP that is sex specific for male recreational runners.