肌力对足关节接触特征影响的生物力学研究

目的 探究足踝体外生物力学实验中肌力对足关节接触力、峰值压强以及接触面积的影响,为选择合适的加载方式提供依据。 方法 踝关节中立位状态下,对新鲜小腿和足离体标本分别进行有无肌力两种方式加载,测量加载状态下第 1 跖趾关节、第 2 跖趾关节、第 1 跖楔关节、第 2 跖楔关节、内侧楔舟关节、中间楔舟关节、距舟关节、 跟骰关节、距下关节(后关节面)以及胫距关节的接触力、峰值压强和接触面积,并对结果进行对比分析。 结果 与无肌力加载状态相比,进行肌力加载时足第 1 跖趾关节、第 2 跖趾关节、第 1 跖楔关节、第 2 跖楔关节、内侧楔舟关节、中间楔舟关节、距舟关节和胫距关节的关节接触力均显著增大( P < 0. 05),变化百分比分别为 719. 28%、311. 37%、128. 67%、50. 82%、54. 89%、57. 63%、79. 98% 和 50. 34% ;足第 1 跖趾关节、第 1 跖楔关节和距舟关节的关节峰值压强显著增大(P<0. 05),变化百分比分别为 176. 14%、62. 91% 和 40. 07% ;足第 1 跖趾关节、第 1 跖楔关节、中间楔舟关节以及距下关节(后关节面) 的关节接触面积均显著增大( P < 0. 05),变化百分比分别为 132. 20%、55. 41%、30. 97% 和 26. 87% 。 结论 足踝标本生物力学实验中,进行肌力加载对足各关节的关节接触力、峰值压强或接触面积均产生显著影响,前足表现尤甚。 在进行相关体外标本研究时,需要考虑肌力加载对足踝受力情况的影响,为足踝生物力学实验提供参考。     

外侧楔形鞋垫对足踝生物力学影响的有限元分析

目的 探究外侧楔形鞋垫对足踝内部组织(包括足骨、关节和韧带)的生物力学影响。 方法 建立并验证足踝-鞋垫-地面三维有限元模型,探究步态 3 个关键瞬间赤足模型和鞋垫干预模型的足底压力分布、关节接触压力、跖骨及主要韧带的应力。 结果 5°外侧楔形鞋垫模型足底峰值压力比赤足模型减小 65. 8% 。 鞋垫干预使楔舟关节处峰值接触压力减小;距下关节处峰值接触压力和第 4、5 跖骨处峰值应力增大。 结论 本研究量化评估了外侧楔形鞋垫对足踝各部分的生物力学影响,提出了可适当减小外侧楔形鞋垫第 4、5 跖骨处倾斜角度的设计建议。     

足踝有限元模型的建立与初步临床应用

建立足踝部有限元模型，研究胫后肌腱功能不全（DPTT）、躅外翻与第一跖列不稳的静态生物力学变化。以螺旋CT扫描正常足部图像为资源，Matlab、Surfacer、ANSYS软件为工具，建立足部有限元模型，模拟静态直立时加载，分别分析跟骨应力应变、胫后肌腱功能不全与第一跖列失稳时的内侧纵弓关节应力应变、骨骼空间位置的的变化。静态直立负重时，跟骨与第一跖骨跖侧应力最大，其中跟骨内侧最大；胫后肌腱功能不全时，可以导致第一跖列的稳定性丧失，进而发生内侧纵弓各个关节之间应力分布、大小发生变化，第一跖骨内收、跖屈，躅趾相对于第一跖骨外展趋势增大。足踝有限元模型是分析足踝生物力学的有力工具；跟痛症的发生与应力反复作用有关；DPPT可以导致第一跖列失稳，进而引起第一跖骨内收、趾外展，与反复应力作用下的躅外翻发生发展有一定关系。     

穿不同鞋与裸足对羽毛球蹬地动作下肢及跖趾关节运动协调特征的影响

目的探讨穿着不同鞋和裸足对羽毛球典型蹬跨步动作蹬地时腿下肢和跖趾关节运动协调的影响,为羽毛球运动的科学训练和专用鞋的选择及研发提供理论基础。方法选取优秀男子羽毛球运动员作为研究对象,穿着某品牌羽毛球成品鞋、某款羽毛球样品鞋和裸足作为不同鞋条件,并以羽毛球典型蹬跨步作为测试动作。利用Vicon运动捕捉系统和高速摄像仪同步采集下肢蹬地过程中髋、膝、踝和跖趾关节的运动学及协调特征。结果(1)在蹬地阶段,穿着两款羽毛球专项鞋时下肢各关节的运动学表现并无显著性差异,但相比裸足,两款鞋均在一定程度上增加踝、跖趾关节的角速度,并显著减低各关节角速度到达峰值的时间;(2)下肢运动协调特征方面,3种足鞋条件均表现为在相近时间内下肢髋、膝、踝和跖趾关节由近及远依次加速蹬伸。结论穿着运动鞋具备更好的蹬伸动力来源,能增加蹬伸的速度和效果,有利于提高运动表现;羽毛球蹬伸动作协调性的表现形式倾向于顺序性与同步性的合理组合,建议应针对性地加强踝、跖趾等末端关节的速度和力量训练。     

唐氏综合征患儿站立时足踝应力传导模式研究

目的 探究唐氏综合征患儿站立时足部内结构的关节接触力、韧带拉力和力传导模式。方法 基于1名唐氏综合征患儿与1名典型健康儿童CT影像学数据,分别建立足部有限元模型,采用静态站立下的足底压力分布实测数据验证模型。模拟站立时足踝受力,以地面反作用力和小腿三头肌肌力作为加载条件,计算分析胫距、距舟和跟骰关节的关节接触压力、弹簧韧带和足底短韧带的拉力,以及跗横关节处的力传导模式。结果 足部有限元模型可靠且有效。与健康儿童相比,患儿胫距关节的接触压力更高,距舟关节的接触压力更低;患儿弹簧韧带和足底短韧带的拉力分别是健康儿童的10倍和58倍;患儿跗横关节的关节间力均小于健康儿童。结论 唐氏综合征患儿站立时存在异常的胫距关节接触压力、较大的中足韧带拉力及较小的跗横关节传导力。临床康复应充分考虑唐氏综合征患儿足部内结构应力模式的异常变化,为筛选和制定早期康复介入计划和设计个性化矫形鞋垫提供理论支撑。     

足底软组织硬化对足部生物力学影响的三维有限元分析

目的 通过有限元方法来研究足底软组织整体硬化以及跖骨头和跟骨下方软组织局部硬化对人体足踝系统的力学影响。方法 基于健康志愿者右足的核磁共振扫描图片建立足部三维有限元模型,通过改变足底软组织的生物力学属性和人体平衡站立位时的计算仿真来分析足底软组织的生物力学问题。同时,对此志愿者进行足底压力测试来验证模型的有效性。结果 建立足踝有限元模型得到了有效的验证并完成了不同软组织属性定义下站立位的运算;在平衡站立位时足底接触压力分布状况和足踝内部一些软、硬组织的受力情况得到量化。结论 软组织硬化,特别是跖骨头和跟骨下方软组织局部硬化,对足底受压接触面积、压力峰值以及足底软组织垫所受的应力等产生了明显影响,大大增加了糖尿病患者发生足底溃烂的可能性。     

有限元建模分析牵开成形治疗踝关节骨性关节炎的生物力学响应

背景：目前踝关节骨性关节炎的手术方式包括关节置换和关节融合,但2种方式均存在一定问题,因此保踝治疗成为踝关节骨性关节炎初期治疗的首选方式。牵开成形是一种重要的保踝治疗术式,有利于缓解踝关节疼痛和改善功能,有助于关节软骨的自我修复,但现在仍缺乏确切的生物力学证据。目的：通过有限元建模探究踝关节牵开成形治疗早中期无明显力线改变的踝关节骨性关节炎的力学因素,为临床治疗提供力学证据。方法：将1名27岁志愿者足踝CT扫描数据DICOM文件导入有限元软件中,进行三维重建及曲面拟合,再进行网格划分,建立含有骨骼、韧带、肌腱和软骨的精细足踝有限元模型,对比踝骨关节炎组、外固定架组分别在中立0°、跖屈20°、背屈20°3种不同工况下的胫距关节面应力、距骨应力及距骨应变的生物力学响应。结果与结论：（1）经过有限元仿真计算发现,从踝关节整体受力来说,两组模型在中立位0°时最小,从中立位逐渐跖屈或背屈时,随着踝关节活动发生变化,应力值也逐渐增加,且在同等屈曲的条件下,背屈要比跖屈的整体应力增幅明显;（2）从胫距关节的应力峰值来说,踝骨关节炎组的胫距关节面应力峰值较正常组增幅明显,外固定架组的胫距关节面应力峰值...     

距下关节在成人足三维运动中的力学研究

目的:分析研究成人新鲜足标本距下关节在正常情况下足三维运动中的生物力学特性。方法:取新鲜足标本12例,通过加载使足产生某种形式的运动,用三维数字化坐标仪测量距下关节组成骨在某种运动状态下的相对三维坐标位移,通过矩阵转换和求解非线性函数方程计算其三维旋转角度,确定距下关节的运动范围、规律和在足整体运动中的作用。结果:距下关节在足整体运动中背屈-跖屈、内翻-外翻、内收-外展轴运动范围分别为4.13°±0.86°、8.43°±0.52°、12.77°±1.29°。在足单纯跖屈背屈、内翻外翻、内收外展过程中,对距下关节三维运动度作相关性分析,并对相关系数进行t检验,相关系数均有高度统计学意义。结论:随足跖屈、背屈,内、外翻,内收、外展运动度的增加,距下关节三维运动范围呈线性增加,在各轴上的增加幅度有所不同,三轴方向上的运动存在密切的相关关系。     

个性化踝关节假体的设计及三维有限元分析

目的针对当前踝关节假体失效率高、临床应用风险大的问题,提出一种个性化解剖型踝关节假体的设计。方法首先建立正常人体足踝系统的三维有限元非线性模型,对模型的有效性进行验证;设计解剖型踝关节假体,对全踝关节假体置换进行几何仿真,建立假体-足踝系统的三维有限元模型;施加步态载荷,计算分析假体的生物力学特性。结果正常踝关节系统足底最大接触应力为214.6 k Pa,足骨最大等效应力为8.96 MPa。对比文献与仿真所得足底反力与足骨应力,验证了正常足踝有限元模型的可靠性。假体植入后,仿真所得距骨钛合金假体、聚乙烯衬垫、胫骨假体等效应力峰值分别为23.88、19.24、73.01 MPa,足踝假体应力相较正常足踝应力有大幅度上升。结论有限元分析的对比结果考察了个性化踝关节假体的可行性,为进一步假体设计优化以及临床应用提供参考。     

内侧柱稳定手术治疗Ⅱ期成人胫后肌腱功能不全性平足的三维有限元生物力学分析

文题释义：平足内侧柱稳定手术：是指通过实施融合固定手术即融合舟楔关节或者跖楔关节,或者两者均融合来稳定足的第一跖列,恢复内侧纵弓的高度,纠正前足的旋前。 背景：平足症是足踝外科的常见病,其中Ⅱ期成人获得性平足在临床上最多见,此期的治疗最为关键。然而Ⅱ期平足内侧柱存在着不稳定,这也是造成足弓塌陷的重要原因。内侧柱稳定手术可以相当程度地纠正畸形,但是目前尚缺乏详细的生物力学实验来全面判断内侧柱稳定后对于全足带来的影响。 目的：探讨单纯内侧柱稳定手术对Ⅱ期成人获得性平足足部生物力学的影响。 方法：首先建立Ⅱa期及Ⅱb期成人获得性平足三维有限元模型,通过Geomagic软件、Solidwork软件及Abaqus软件模拟内侧柱稳定手术(舟楔关节融合､跖楔关节融合､两者均融合),将术前和术后模型模拟单倍体质量负重,比较其足底、内外侧柱骨块、内侧韧带的最大应力值,并通过测量相关参数来进行综合对比。 结果与结论：①单纯内侧柱稳定术后模拟负重时足底应力最大值均出现在第一跖骨头下方,其中Ⅱa期模型行内侧柱稳定后足底应力最大值明显增加,Ⅱb期模型内侧柱稳定后足底应力变化不明显;②内侧柱融合后相应关节的应力有所减轻,但对于第一跖列的其他关节应力反而增加了;③内侧柱融合后对于内侧韧带及足底筋膜的应力均没有减轻作用;④结果表明,单纯内侧柱稳定手术并不能降低Ⅱ期成人获得性平足内侧柱的压力,它仅可以作为联合使用的手术来稳定过度活动的关节以及纠正前足旋后畸形。 ORCID: 0000-0002-8230-1151(刘付胜华) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

跖腱膜对第1跖趾关节活动的影响

目的　认识跖腱膜对维持第1跖趾关节稳定性的作用,探讨早期　僵硬手术治疗的可行性。 方法　采用6例新鲜尸体足标本,固定于自制生物力学加载支架,用逐级定量的方法对第1跖趾关节进行力学加载,测量跖腱膜离断前后第1跖趾关节背屈活动范围的变化。 结果　跖腱膜离断前第1跖趾关节背屈为（68.34±3.05）°,跖腱膜离断后背屈为（78.50±3.77）°,较离断前增加了（10.16±2.10）°（t=11.83,P<0.05）。 结论　跖腱膜对维持第1跖趾关节稳定有重要作用,损伤后要尽可能修复;某些足部疾病的治疗如需离断跖腱膜,尽量做部分离断;跖腱膜切开术可能是治疗早期拇僵硬可以选择的一种手术方法。     

An investigation of the dynamic relationship between navicular drop and first metatarsophalangeal joint dorsal excursion

The modern human foot is a complex biomechanical structure that must act both as a shock absorber and as a propulsive strut during the stance phase of gait. Understanding the ways in which foot segments interact can illuminate the mechanics of foot function in healthy and pathological humans. It has been proposed that increased values of medial longitudinal arch deformation can limit metatarsophalangeal joint excursion via tension in the plantar aponeurosis. However, this model has not been tested directly in a dynamic setting. In this study, we tested the hypothesis that during the stance phase, subtalar pronation (stretching of the plantar aponeurosis and subsequent lowering of the medial longitudinal arch) will negatively affect the amount of first metatarsophalangeal joint excursion occurring at push‐off. Vertical descent of the navicular (a proxy for subtalar pronation) and first metatarsophalangeal joint dorsal excursion were measured during steady locomotion over a flat substrate on a novel sample consisting of asymptomatic adult males and females, many of whom are habitually unshod. Least‐squares regression analyses indicated that, contrary to the hypothesis, navicular drop did not explain a significant amount of variation in first metatarsophalangeal joint dorsal excursion. These results suggest that, in an asymptomatic subject, the plantar aponeurosis and the associated foot bones can function effectively within the normal range of subtalar pronation that takes place during walking gait. From a clinical standpoint, this study highlights the need for investigating the in vivo kinematic relationship between subtalar pronation and metatarsophalangeal joint dorsiflexion in symptomatic populations, and also the need to explore other factors that may affect the kinematics of asymptomatic feet.     

Mechanical Analysis of Foot Plantar Fascia in Normal Walking Condition

Foot plantar fascia is a kind of important tissue in stabilizing the longitudinal arch of human foot. Direct measurement to monitoring the mechanical situation of plantar fascia at human locomotion is very difficult. The purpose of this study is to construct a three-dimensional finite element model of the foot to calculate the internal stress/strain value of plantar fascia during different stages of the gait. The simulated stress distribution of plantar fascia was the lowest at heel-strike,which concentrated on the medial side of calcaneal tubercle. The peak stress of plantar fascia was appeared at push-off,and the value was more than 5 times of the heel-strike position. Current FE model was able to explore the plantar fascia tension trend at the main subphases of the foot. More detailed fascia models and intrinsic muscle forces could be developed in the further study.     

Using an Optimization Approach to Design an Insole for Lowering Plantar Fascia Stress—A Finite Element Study

Plantar heel pain is a commonly encountered orthopedic problem and is most often caused by plantar fasciitis. In recent years, different shapes of insole have been used to treat plantar fasciitis. However, little research has been focused on the junction stress between the plantar fascia and the calcaneus when wearing different shapes of insole. Therefore, this study aimed to employ a finite element (FE) method to investigate the relationship between different shapes of insole and the junction stress, and accordingly design an optimal insole to lower fascia stress. A detailed 3D foot FE model was created using ANSYS 9.0 software. The FE model calculation was compared to the Pedar device measurements to validate the FE model. After the FE model validation, this study conducted parametric analysis of six different insoles and used optimization analysis to determine the optimal insole which minimized the junction stress between plantar fascia and calcaneus. This FE analysis found that the plantar fascia stress and peak pressure when using the optimal insole were lower by 14% and 38.9%, respectively, than those when using the flat insole. In addition, the stress variation in plantar fascia was associated with the different shapes of insole.     

基于有限元法对足跟痛在推离期的生物力学研究

基于有限元法对推离期下足跟痛的发病和康复机理进行研究。采集一位足跟痛患者的CT和MRI图像用于三维重建,利用Geomagic软件对得到的模型表面优化,再通过Hypermesh软件对模型进行有限元前处理,最后将得到的下肢有限元模型导入到Abaqus中分析计算,与足底压力板测试结果对比验证模型的有效性,并根据计算结果分析小腿三头肌力的变化对足踝步态推离期生物力学行为特性的影响。结果表明,小腿三头肌肌肉力从550 N增大到1 100 N的过程中,第一趾骨区的峰值压力增大了32.8%,跖骨区的峰值压力增大了14.3%;第一根足底筋膜的应力高达4.69 MPa;跟腱与跟骨连接处和跟骨结节部位的应力峰值分别为28.36和32.79 MPa。由此可见,小腿三头肌挛缩和推离期的绞盘效应会导致足底筋膜过度拉伸,引起跟骨结节处的应力水平提高,使得足部生物力学环境发生变化,从而诱发足底筋膜炎,导致足跟痛。缓解小腿三头肌挛缩、减小肌肉力、避免足底筋膜过度拉伸及降低附着点处的应力水平以恢复足部正常生物力学环境,是治疗足跟痛的主要康复机理。     

Design and validation of a dynamic stretch splint for plantar fasciitis

BackgroundPlantar fascia stretch plays an important role in the treatment of plantar fasciitis. Existing stretch splints mostly provide stretch to Achilles tendon but not to the plantar fascia. The ones that do are inefficient and uncomfortable because of their static nature. In this paper a dynamic stretch splint featured both ankle and metatarsophalangeal joint stretch was designed and developed. This splint should provide continuous stable stretch and be able to monitor the load of stretch during clinical application. To validate the design, twenty volunteers were tested under two stretch conditions, static and dynamic. Forces generated between the splint and the foot across 30-min testing were registered. Level of comfort and joint range-of-motion changes after splint application were evaluated. Statistical results demonstrated significant differences in load of stretch and in level of comfort between the static and dynamic conditions, but not in joint range-of-motion. The findings indicated that the designed splint could provide a continuous load of stretch, eliminate discomfort and increase user compliance comparing to static splint. Its long term effect onto joint angle improvement needs further investigation. Potentially it may be used on subjects with plantar fasciitis, and subjects with foot problems accompanying plantar tissue contracture.     

The innervation of the joints of the foot

The nerve supply of the ankle joint and of the joints of the foot was studied in dissections of fetal and adult feet and in serial sections of fetal feet stained with silver. The ankle joint was supplied by the tibial, sural, deep peroneal, and saphenous nerves, and by the accessory deep peroneal nerve when present. The tarsal joints were supplied on their plantar aspects by the medial or lateral plantar nerves, and on their dorsal aspects chiefly by the deep peroneal nerve. The joint between the lateral and intermediate cuneiform received branches from the intermediate dorsal cutaneous nerve also. The lateral dorsal cutaneous nerve and the accessory deep peroneal nerve when present provided additional branches to the subtalar and calcaneocuboid joints. The tarsometatarsal joints were supplied on their plantar aspects by the medial or lateral plantar nerves. Most of them were supplied on their dorsal aspects by the deep peroneal nerve, but the cuboid-metatarsal joints received their supply from the intermediate dorsal cutaneous nerve. The intermetatarsal joints had a similar but sparser supply. The joint between the fourth and fifth metatarsal received branches from the intermediate dorsal cutaneous nerve. The plantar digital nerves provided the main supply to the metatarsophalangeal joints. The dorsal aspect of the first metatarsophalangeal joint was supplied by the deep peroneal and the medial dorsal cutaneous nerves, of the second metatarsophalangeal joint by the deep peroneal nerve, and of the fourth and fifth metatarsophalangeal joints by the lateral dorsal cutaneous nerve. The interphalangeal joints did not receive articular branches from the dorsal digital nerves, except in the case of the interphalangeal joint of the big toe, which was supplied by the deep peroneal and the medial dorsal cutaneous nerves.     

行走支撑期足弓变化规律与足功能转换机制

目的 通过分析行走步态参数和足弓力学结构,探究行走支撑期足弓功能的转化机制及变化规律。 方法 利用动作捕捉系统及足底压力测试系统同步采集 8 名受试者不同步速行走时的步态参数及横、纵弓角度。 使用单 因素重复测量方差分析检验不同步速下足横、纵弓角度变化及足底受力的特征值差异。 结果 行走支撑期,纵弓 角度、横弓角度及足底受力曲线均存在两个特征值,3 条曲线特征值在 4 种步速下存在一致性规律。 1. 4 倍和 1. 2 倍最适速度行走时,蹬伸离地阶段时长显著性高于 0. 8 倍最适速度(P<0. 05),横弓升高的拐点和第 1 个受力 峰值出现时间早于 0. 8 倍最适步速(P<0. 05);1. 4 倍最适步速相比于 0. 8 倍最适速度横弓在蹬伸离地阶段的最小 角度显著性增加(P<0. 05),最小角度出现的时间显著性提前(P<0. 05);1. 2 倍最适速度步行时,纵弓第 2 个峰值 出现的位置相比于最适速度提前(P<0. 05)。 结论 行走支撑期,足以纵弓、横弓升降实现功能转化。 足纵弓和足 横弓共同降低完成缓冲,纵弓降低、横弓升高使足增加刚性完成蹬伸。 在执行蹬伸推进功能时,步速增加会加大蹬 伸离地阶段在步态支撑期的时间占比,足横弓和纵弓的变化随蹬伸期提前。 探究足弓变化及足功能转化机制对了 解足部运动规律及足踝康复具有重要的指导意义。     

Physiological and biomechanical comparison of roller skating and speed skating on ice

Summary Eight well trained marathon skaters performed all-out exercise tests during speed skating on ice and roller skating. To compare these skating activities in relation to the concept of training specificity, relevant physiological (V _O2,V _E, RER and heart rate) and biomechanical variables (derived from film and video analysis) were measured. There were no significant differences between oxygen uptake (50.5±8.0 and 53.3±6.7 ml·min^–1·kg^–1), ventilation (102.4±11.2 and 116.0±11.1 l·min^–1) or heart rate (174±12.2 and 176±14.5 min^–1) between speed and roller skating. In roller skating a higher RER (1.16±0.1 cf. 1.05±0.1) was found. Power, work per stroke and stroke frequency were equal. Due to a higher coefficient of friction the maximal roller skating speed was lower. The effectiveness of push-off and parameters concerning the skating techniques showed no differences. In roller skating a 7.5% higher angle of the upper leg in the gliding phase occurred. It is speculated that the blood flow through the extensor muscles might be higher in roller skating. It is concluded that roller skating can be considered as a specific training method which may be used by trained speed skaters in the summer period.