预期条件下不同侧切角度膝关节应力状态的有限元分析

目的 探讨预期条件下不同角度侧切触地过程中膝关节运动学、地面反作用力（ground reaction force, GRF）特征以及软骨、半月板的应力状态。方法 采集14名受试者在预期条件下分别进行45°、90°和135°侧切时的运动学和GRF数据，通过Visual 3D逆动力学计算获取膝关节反作用力，基于膝关节三维有限元模型分别对3种侧切角度下触地过程进行数值仿真。结果 预期条件下3种侧切角度在触地过程中的膝关节运动学特征存在显著性差异（P＜0.001），膝关节屈曲程度随侧切角增大而增加；垂直GRF随侧切角增加而显著减小（P＜0.001），水平GRF呈现出相反的趋势；3种侧切角度下，90°侧切时髌骨软骨以及股骨软骨接触应力峰值较大, 前交叉韧带（anterior cruciate ligament，ACL）接触点主应力峰值较大，其次为135°和45°侧切；3种侧切角度下，外侧股骨软骨接触应力峰值均大于内侧。结论 90°侧切运动时膝关节损伤风险更大，135°侧切时膝关节内部的应力状态与90°侧切相比较为良好。预期条件下膝关节损伤风险并不随侧切角增大而升高。     

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。     

前交叉韧带重建后急停起跳过程中膝关节应力的有限元分析

背景：已有研究分析了前交叉韧带重建患者术后完成不同动作时健患侧运动学、动力学等运动特征,假设前交叉韧带重建术后患者在完成急停起跳动作时健侧前交叉韧带von Mises应力较患侧高,半月板和股骨软骨的von Mises应力较患侧低。目的：通过探究前交叉韧带重建患者健患侧膝关节软组织的应力响应特征,以期为降低该人群发生前交叉韧带二次损伤及慢性膝关节骨性关节炎等继发性损伤提供参考。方法：运用红外光点运动捕捉系统(Nokov)和测力台(Bertec)采集前交叉韧带重建患者急停起跳时膝关节运动学和动力学特征,通过欧拉角计算方法和逆动力获得膝关节三维角度和三维力矩参数,并将膝关节三维角度和力矩作为边界和加载条件分别载入健患侧膝关节有限元模型,进行数值仿真,比较健患侧膝关节内部结构在实际运动载荷下的应力分布情况。结果与结论：(1)在水平向后第一地面反作用力峰值时刻,患侧膝关节屈曲角、内收角明显大于健侧,且健侧垂直地面反作用力高于患侧。此外,健侧垂直地面反作用力峰值出现在急停起跳阶段的4%-6%,而患侧出现在急停起跳阶段的15%-17%,表现出健侧腿较患侧先着地的运动模式。(2)有限元分析显示健侧前交...     

前交叉韧带重建术后关节粘连患者在体胫股关节运动学分析

目的 定量分析前交叉韧带重建(anterior cruciate ligament reconstruction, ACLR)术后关节粘连患者在体胫股关节 6 自由度的运动学特征。 方法 纳入 15 例 ACLR 术后关节粘连患者和 15 例健康受试者,运用便携式膝关节三维运动分析系统采集受试者负重屈膝和非负重屈膝时胫股相对于股骨的运动轨迹,获取胫股关节 6 自由度的运动学数据。 结果 与健康人相比,负重屈膝 30°、45°、60°和 75°时,膝关节粘连患者患侧胫骨内旋角度明显减少(P<0. 001);负重屈膝 30° 和 45° 时,膝关节粘连患者患侧胫骨相对于股骨的外翻角度较健康人明显减小(P<0. 05)。 非负重屈膝 75°时,膝关节粘连患者患侧胫骨内移距离较健康人明显减少(P<0. 05)。 结论 关节粘连限制了胫骨相对于股骨的旋转和内外移,对于胫骨相对于股骨的前后移动影响不大。 因此,临床上应该利用各种治疗手段松解股骨内外侧沟的粘连和外侧副韧带挛缩,解决旋转和内外移动受限的问题,以最大程度恢复膝关节功能。     

性别和动作对排球运动员前交叉韧带损伤危险因素的影响

目的 研究性别和动作对排球运动员前交叉韧带（anterior cruciate ligament, ACL） 损伤危险因素的影响。方法 采集排球运动员急停起跳、起跳垂直落地和急停变向跑时的运动生物力学数据,运用蒙特卡罗模拟得到运动员ACL损伤概率和损伤试跳的生物力学参数。采用2×3混合设计的双因素方差分析验证性别和动作对损伤危险因素的影响。结果 不论男女,变向跑ACL损伤危险性最大（P＜0.001）。变向跑和急停起跳时,女子比男子运动员ACL损伤危险更大（P＜0.001）。垂直落地时,男子比女子运动员更易发生损伤（P＜0.001）。排球运动员ACL损伤危险因素均受性别和动作的显著性交互作用（P＜0.001）。结论 变向跑时,男子运动员由于膝关节屈角小、小腿趋于前倾以及足跟着地而增加ACL负荷,女子运动员倾向于由于较大地面反作用力和膝关节伸展力矩而增加损伤风险。膝关节屈角小是运动员急停起跳的主要损伤因素,且男子因素更繁杂。垂直落地时,女子运动员损伤危险因素是地面反作用力、膝关节外翻和伸展力矩及足跟着地等;较小的膝关节屈角是男子运动员损伤危险因素。研究结果可为排球运动员ACL损伤风险评价、个性化损伤预防方案制定、临床与康复治疗等提供依据。     

踝关节贴扎在优势侧落地动作中对膝关节生物力学特性的影响

目的 研究踝关节贴扎（限制踝关节内翻跖屈）在优势侧单腿落地动作中对膝关节生物力学特征的影响。方法 在踝关节未贴扎和贴扎两个条件下,18位业余运动员执行优势侧单腿落地动作,使用Vicon三维运动捕捉系统、Kistler测力台和Noraxon 表面肌电系统共同采集运动学、动力学、表面肌电数据,进行统计学分析。结果 与未贴扎相比,贴扎后触地时刻的膝关节屈曲角度和接触地面过程中膝关节最大屈曲角度显著性增加,而膝关节最大外翻角度显著性减小。结论 限制踝关节内翻跖屈贴扎可能会降低前交叉韧带损伤的风险。踝关节贴扎的干预方式能够改变在落地动作中膝关节生物力学指标。限制踝关节内翻跖屈贴扎可以作为预防大学生运动员前交叉韧带损伤的有效措施。     

肌内效贴对下肢侧切运动中生物力学特征的影响

背景:肌内效贴扎作为一种运动防护手段已被广泛应用,但作为纠正侧切动作时下肢生物力学异常变化手段的研究,其作用尚不明确。目的:对比受试者膝关节在肌内效贴扎、安慰剂贴扎及空白对照情况下,完成侧切动作时下肢运动学、动力学特征的变化。方法:招募39名篮球专项男性大学生为受试者,每位受试者分别在肌内效贴扎、安慰剂贴扎以及不进行任何贴扎情况下进行测试。采取力学矫正的贴扎方式对受试者优势侧膝关节进行贴扎干预。选取4.5-5.5 m/s的助跑速度完成45°侧切动作,并运用三维动态捕捉系统及测力台同步采集运动学及动力学数据。选取初始触地时刻、地面反作用力峰值时刻的运动学及动力学参数进行数据分析。采用SPSS 27.0软件对测试数据进行统计学分析。结果与结论:①运动学指标:肌内效贴条件下与无贴扎及安慰剂贴扎相比,初始触地时刻髋关节外展、膝关节外翻角度显著减小(P<0.05);侧向地面反作用力峰值时刻,髋关节外展、膝关节外翻及踝关节跖屈角度显著减小(P<0.05),膝关节屈曲角度显著增加(P<0.05)。②动力学指标:与无贴扎相比,肌内效贴扎及安慰剂贴扎条件下均可显著减小初始触地时刻髋关节外展、外旋力矩及膝关节外翻、外旋力矩(P<0.05),显著减小垂直地面反作用力峰值、水平向后地面反作用力峰值(P<0.05);与无贴扎及安慰剂贴扎相比,肌内效贴扎可显著减小侧向地面反作用力峰值(P<0.05)。③结果表明,对膝关节进行肌内效贴扎可在一定程度上改善篮球专项大学生在完成侧切动作时与下肢损伤风险因素相关的部分运动学、动力学指标,可能对预防侧切过程中损伤的发生有一定积极作用;此外,膝关节安慰剂贴扎与肌内效贴扎在部分指标变化方面的作用趋势较为一致,提示肌内效贴扎的作用机制可能存在安慰剂效应。     

腓骨头复合组织瓣切取后膝关节生物力学的稳定性

背景：股二头肌腱和外侧副韧带是膝关节后外侧复合体的重要组成成分,对维持膝关节后外侧稳定性有重要意义。 目的：观察腓骨头复合组织瓣切取后供区股二头肌腱和外侧副韧带下止点重建对膝关节稳定性的影响。 方法：选择10例男性新鲜冷冻膝关节尸体标本,利用生物力学扭转试验机测量腓骨头复合组织瓣切取前及股二头肌腱和外侧副韧带下止点重建后不同转矩下的胫骨外旋角。 结果与结论：同一转矩条件下,胫骨外旋角随膝关节屈曲角度的增大而变大,腓骨头复合组织瓣切取前及股二头肌腱和外侧副韧带下止点重建后比较差异无显著性意义;不同外旋转距条件下,外旋角变化的趋势一致。提示腓骨头复合组织瓣切取后,妥善重建股二头肌腱和外侧副韧带下止点,不会对膝关节稳定性造成显著影响。     

股骨内翻和胫骨内翻的运动学和足底压力分析

目的 探究胫骨侧和股骨侧来源的两种单侧膝骨关节炎膝内翻在步态分析中的运动学参数和足底压力差异,为不同类型膝内翻提供生物力学理论基础。方法 招募26名单侧膝骨关节炎型膝内翻患者,股骨侧和胫骨侧来源各13名受试者。利用Noraxon MyoMotion三维动作捕捉系统和Footscan平板式足底压力测试系统,测量受试者在自然行走状态下的步态,采集受试者步态的时空指标、下肢各关节运动学参数、足底压力,并进行两组间对比分析。结果 胫骨侧膝内翻的膝关节屈伸范围、髋关节外展峰值、髋关节内收外展活动范围、踝关节内旋峰值均大于股骨侧膝内翻,而膝关节屈曲峰值、髋关节内收峰值小于股骨侧膝内翻;与股骨侧膝内翻相比,胫骨侧膝内翻受试者第4、5跖骨足底受力时间、压力峰值都增加(P<0.05)。在第3跖骨区域中,股骨健侧肢体比胫骨畸形健侧肢体的冲量更大;而在足跟内侧区域,股骨健侧肢体的冲量更小(P<0.05)。结论 两种不同类型单侧膝内翻患者在运动学参数和足底压力方面存在一定差异。研究结果有助于正确认识膝内翻引起的异常步态,为不同类型膝内翻诊治、术后康复和肢体锻炼提供可靠参考。     

单髁置换术应用于骨关节炎合并前交叉韧带缺失的三维有限元研究

目的采用有限元方法比较前交叉韧带(anterior cruciate ligament,ACL)完整与缺失的骨关节炎患者单髁关节置换(unicompartmental knee arthroplasty,UKA)术后膝关节生物力学特性,分析ACL缺失对膝关节单髁置换术后的运动和应力的影响。方法根据膝关节CT、MRI图像,建立有限元模型。采用逆向工程技术重建活动衬垫单髁假体,加载入该正常膝关节三维有限元模型。在不同屈膝角度(0°、30°、60°、90°、120°)加载载荷,观察在ACL完整(ACL-intact,ACLI)和缺失(ACL-deficiency,ACLD)情况下,膝关节的最大接触压和位移程度。结果 UKA-ACLI与UKA-ACLD模型在膝关节屈膝各角度,各部位(外侧股骨软骨、胫骨软骨、半月板、股骨假体、胫骨假体、衬垫)最大应力无明显差异,ACLD模型在膝关节屈膝0°和30°位前后位移明显大于ACLI模型,在膝关节屈膝0°位股骨相对内旋减小,在膝关节屈膝30°位股骨相对外旋增加。结论标准位置假体植入情况下,ACL缺失并不会导致UKA术后应力异常增大,会导致在膝关节伸直位时位移增加。     

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     

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.     

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.     

Electromyographic analysis of the knee during jump landing in male and female athletes

Many noncontact anterior cruciate ligament (ACL) injuries in female athletes occur at foot strike during jump landing when the knee is extended. This study was undertaken to determine the activation level of the quadriceps and hamstring muscles electromyographically. Fifteen healthy volunteers (eight women and seven men), all of whom were collegiate basketball players, participated in the study. The maximum voluntary contraction (MVC) of the vastus medialis (VM) at a knee flexion angle of 15-45 degrees was significantly higher in women than in men. There was no significant difference in overall mean hamstring activity in men and women over the same knee flexion range. However, when the knee flexion angle was 15 degrees , 20 degrees , and 25 degrees , hamstring activity was significantly lower in female athletes. These results suggest that female athletes have a higher risk of ACL injury during jump landing due to increased anterior tibial translation force with quadriceps muscle activity. Female athletes require greater hamstring activation, and it is suggested that exercising this muscle will increase its activity when the knee is extended, thus preventing ACL injury during actual sport motions.     

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.     

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.

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.     

Motion of the anterior cruciate ligament during internal and external rotation at the knee: A cadaveric study

Despite advances in our understanding of anterior cruciate ligament (ACL) anatomy and function, the change in position of the ACL during tibial rotation is not well understood. The purpose of this study was to quantify and compare the movements of the anteromedial (AM) and posterolateral (PL) bundles of the ACL during 15° of medial and lateral rotation (with & without a shear force). Cadaveric knees (12 male/12 female) were dissected and mounted at 90° of knee flexion. Anthropometric features of the ACL and distal femur were recorded, and each bundle was marked at: femoral attachment (FA), midpoint of ligament (MP), and tibial attachment (TA). Digital images of ACL motion in the frontal plane were taken as the tibia was rotated about a fixed femur. Using digitizing software, the change in position of the markers was quantified. Measurements suggested the ACL pattern of motion was consistent between sexes, regardless of shear force. The greatest amount of movement of both the AM and PM bundles occurred at the TA marker. The FA marker moved more during medial rotation, and the MP and TA markers moved more with lateral rotation. The 20 lb‐shear force affected medial rotation most. This study is the first to quantify movement of the ACL during medial and lateral tibial rotation. Data should assist surgeons to select a graft position that is capable of replicating the rotational movement of the native ACL, and help improve three‐dimensional stability of the ACL reconstructed knee. Clin. Anat. 30:861–867, 2017. © 2017 Wiley Periodicals, Inc.