不同运动鞋舒适性差异及对篮球典型动作足部受力特征影响

目的探讨穿着不同篮球专项鞋在不同篮球典型步法中足部受力特征和专项鞋舒适性之间的关系。方法利用Kistler三维测力台和Medilogic鞋垫式足底压力测试系统采集并比较12名篮球专项运动员分别穿着两款篮球鞋(L、N鞋)在完成3种篮球典型步法(侧滑步、90°变向跑、3步上篮)的受力特征,包括冲击力峰值、最大负载率、足底压力峰值等;并采用主观舒适度量表对完成3种步法时两款鞋舒适性进行评分。结果 3种典型步法中两款鞋在冲击力方面无显著性差异,L鞋足部压力在侧滑步和3步上篮中比N鞋更小;在舒适性方面,N鞋显著优于L鞋,主要表现在鞋舒适性喜好程度(后跟稳定性、后跟响应、前掌缓冲、后跟缓冲和总体印象)和强度(前掌缓冲和后跟缓冲)方面存在显著性差异。结论两款篮球鞋仅在足底压力和舒适性评价上存在较大差异,但并没有一款鞋在两种评价中都表现更优异,提示在全面设计和评价专项鞋时应兼顾鞋本身的生物力学特性和运动员的主观评价。     

神经肌肉疲劳前后运动鞋对下肢落地冲击的生物力学影响

目的探讨神经肌肉疲劳前后缓冲型运动鞋对落地动作下肢冲击力特征,以及对运动学和动力学的影响。方法比较15名篮球专项运动员在疲劳干预前后,穿不同缓冲性能的运动鞋从60 cm高落地时的冲击力、负载率、下肢运动学、关节力矩、关节/下肢刚度等。结果疲劳前高缓冲鞋仅使后跟处负载率峰值减小,且到达后跟负载率时间比对照组更短。疲劳后高缓冲鞋显著减小后跟处冲击力峰值、负载率峰值和前脚掌的负载率峰值,同时显著延长到达冲击力和后跟负载率峰值的时间;穿高缓冲鞋使得踝关节触地角度、最小角度显著增大。在下肢刚度、踝关节峰值力矩和刚度方面两组鞋并未发现显著性的改变。结论在疲劳后,当人体下肢神经肌肉控制策略减弱时,高缓冲鞋能够有效地衰减冲击,进而有利于避免或减小潜在的冲击性运动损伤。     

不同鞋条件对后跟着地跑者跟腱负荷特征的影响

目的 探究不同鞋条件（极简鞋和传统跑鞋）对跑步时跟腱负荷特征的影响。方法 招募16名健康男性后跟着地跑步爱好者,要求其以3.16~3.50 m/s速度在两种鞋条件下完成跑步实验。采用超声影像仪获取跟腱横截面积成像。采用运动捕捉系统和三维测力台获取踝关节矢状面运动学和地面反作用力数据,并计算踝关节和跟腱的力学参数。采用配对样本t检验比较两种鞋条件对各因变参数（踝关节角度、触地角度、跟腱力、应力、应变等）的影响。结果 与传统跑鞋相比,穿着极简鞋时的足触地角度显著降低39.9%。同时,踝关节力矩、跟腱力峰值、跟腱负载率峰值和平均负载率均显著增加,而达到跟腱力峰值的时间显著减小。穿着极简鞋时的跟腱应力峰值、跟腱应变峰值及其应力率和应变率峰值也显著增加。结论 习惯穿着传统跑鞋并采用后跟着地的跑者在穿着极简鞋后显著增加了跟腱的负荷特征,建议该类跑者循序渐进地过渡至极简鞋,以适应性地提高跟腱承受负荷的能力。     

个性化足跟痛缓冲鞋垫的生物力学研究

目的研究带有不同结构后跟垫的个性化鞋垫对足跟痛患者足部应力集中的作用效果。方法结合统计学和有限元分析方法,建立足跟痛患者足部及个性化鞋垫有限元模型,仿真模拟不同鞋垫对足跟痛患者足部软组织内外及足底筋膜应力的作用效果。结果足部软组织内部所受应力高于足底表面,足底筋膜应力在第3根筋膜上的应力最高。裸足站立时足跟区软组织内部应力峰值是表面峰值的1.34倍,足底第3根筋膜的应力为1.50 MPa。通过正交试验得到的优化鞋垫模型能够降低足跟区软组织内部应力峰值51.0%,同时缓解足底第3根筋膜应力11.3%。结论带有竖轴椭圆形、蜂窝状孔槽结构后跟垫的个性化缓冲鞋垫方案较优,后跟垫能辅助跟骨脂肪垫吸收或缓冲震荡,较好地减轻足底应力分布集中的同时具有缓解足底筋膜张力的作用。结果有助于认识足跟痛足部的应力分布情况,对研究足跟痛的病理和治疗具有重要的意义。     

不同年龄段人群行走足底压力特征分析

目的获取不同年龄段人群正常行走时足底压力的动力学参数,为设计制作不同年龄段鞋垫和运动鞋提供理论依据,最大程度减小足部发生损伤的风险。方法使用Footscan测力平板对4个年龄段120名受试者(20～30、30～40、40～50、50～60岁男女各15名)足底压力峰值、压强峰值进行测试。结果足底压力峰值随着年龄增长不断变化,大部分呈上升趋势,只有在第1趾骨区域随着年龄的增长压力峰值逐渐减小,第1趾骨区域女性足底压力峰值在逐渐减小;大部分受试者第2、4拓骨头受力明显高于第1、5跖骨; 50～60岁年龄段男性第2跖骨压力峰值也明显大于20～50岁年龄段人群(P0. 05)。随着年龄增长,仅仅第1趾骨压力峰值逐渐减小,其余区域均呈现增长现象;压强峰值有显著变化,尤其以第2、3跖骨变化最大,呈上升趋势(P0. 05)。结论人体足底各分区的压力、压强随着年龄增长并非一成不变,找出每个年龄段人群足底压力特点,制定相应的运动鞋,才能更好发挥运动鞋的功能。     

跑姿再训练对冲击力、下肢生物力学及刚度的影响

目的 通过建立12周跑姿再训练（gait retraining,GR）的干预模式（即通过一定的姿态目标改变跑者原有跑姿）,确定GR前后跑步时垂直地面反作用力（vertical ground reaction force, vGRF）以及髋、膝、踝三关节运动学、动力学和下肢刚度特征的变化,探究跑姿转换对冲击力和下肢生物力学的影响。方法 采用Vicon 运动捕捉系统和Kistler三维测力台同步采集30名跑步爱好者（GR组15人,对照组15人）GR前后穿着极简鞋以 12 km/h±5%速度通过测力台的GRF以及标记点轨迹。结果 共17名受试者（GR组9人,对照组8人）完成训练。训练后两组最大负载率都显著下降,GR组相比对照组最大负载率更低;GR组足部触地角度显著减小,两组跖屈角度和髋关节蹬伸角速度都显著增加;GR组踝关节力矩增加;两组下肢刚度均显著增加。结论 成功建立12周GR运动干预模型（前掌着地转化率为78%）。GR能有效避免冲击力峰值、降低最大负载率、提高下肢刚度,进而在减小甚至避免由冲击力引起的跑步损伤风险的同时,为提高跑步经济性提供可能。     

老年鞋舒适性和安全性的生物力学研究

目的 对老年男性在穿着实验改良鞋进行快走运动时的鞋舒适性和安全性进行评估,为老年鞋具的设计提供数据参考。 方法 16 名 55~ 65 岁男性受试者穿着 3 款不同老年运动鞋,使用视觉模拟评分法( visual analoguescale,VAS)和足底压力参数从主观舒适性和生物力学进行综合评价。 使用垂直地面反作用力( vertical groundreaction force, vGRF)、压力中心(center of pressure, COP)位移和摩擦因数分别从冲击衰减特性、步态稳定性和鞋防滑性三方面对老年运动鞋的安全性进行评价。 结果 在第 2 ~ 5 趾骨区,B 鞋的平均压力、峰值压强均显著低于 A 鞋;在第 2~ 4 跖骨区,B 鞋峰值压强显著低于 C 鞋;在第 5 跖骨区,C 鞋平均压力、峰值压强均显著低于 A、B 鞋;在足弓内侧区,C 鞋平均压力显著高于 A、B 鞋;外侧区,B 鞋平均压力显著低于 C 鞋,峰值压强显著低于 A 鞋。 3 双鞋 vGRF 第 1 峰值力存在显著性差异;B 鞋 vGRF 第 2 峰值力显著低于 C 鞋。 C 鞋足底 COP 在从触地到 vGRF 第 1峰值力产生时间段内左右方向上的位移变化量(COPX-LR)显著高于与 A、B 鞋,而在整个支撑期左右方向上的位移变化量(COPXD)显著高于 B 鞋。 B 鞋脚掌蹬伸摩擦因数峰值显著高于 A、C 鞋,C 鞋着地阶段峰值时刻显著慢于 B 鞋。 结论 B 鞋安全性较高,但仍需进一步的改进以减少第 5 趾骨区的足底压力。 在设计老年人鞋具时,为达到减震缓冲效果而仅采取厚底设计,可能会给老年人的步态稳定性带来负面影响。     

平地自然行走护士的步态特征和足底压力分布◆

背景：繁忙的工作和快速行走的严格要求势必造成护士足部压力增高,甚至引起足部疾病。 目的：分析护士平地自然行走下的步态特征和足底压力分布。 方法：采用比利时RSscan INTERNATIONAL公司生产的足底压力分布测试系统对73名护士进行动态足底压力测试。 结果与结论：护士步态分析中足底压强、冲量、支撑时间数据分析一致：在自然步态下,护士足部最大压强部位在第2、3跖骨区;足部最大冲量部位在前足;支撑期时间所占比例最大的是前足离地阶段;加上护士步速较快,足底压力相应增高,前足压力也随其增大。提示护士前足压力较高,易疲劳而发生运动损伤。因此,护士要科学的选择护士鞋或鞋垫,调整足底压力分布和足底冲量,加强对前足、特别是前足第2~3跖骨区的保护,尽可能避免足部疲劳和损伤的发生。     

着鞋类型和步速对膝关节载荷的影响

目的探讨着鞋类型(裸足、普通鞋、极简鞋)与步行速度(快步走、常速行走)对膝关节生物力学指标的影响,为科学健身提供理论参考。方法采用Vicon三维运动捕捉系统、Kisler三维测力台同步采集10名男性在裸足、穿着不同鞋常速行走与快步走时下肢运动生物力学指标。采用双因素(2种行走方式×3种着鞋类型)重复测量方差分析对各指标进行统计分析。结果相对于快步走,常速行走时足底压力中心(center of pressure,COP)向外偏移较大,额状面膝关节力臂、膝关节内收外力矩和第1峰值负载率均较小,但额状面膝关节冲量矩较大;相对于穿着普通跑鞋,裸足或穿着极简鞋时,步幅变小,COP向外偏移较大,额状面膝关节力臂、膝关节内收外力矩、第1峰值负载率和额状面膝关节冲量矩较小。结论为降低额状面膝关节冲量矩以及峰值负载率,建议着极简鞋采用小步幅进行快步走锻炼。     

不同跑步着地习惯对跟腱形态学及其负荷特征的影响

目的 探究不同着地模式对跟腱形态学和负荷特征的影响。方法 招募习惯后跟着地跑者和习惯前掌着地跑者各14人,利用超声医学影像仪采集受试者的跟腱形态学特征（跟腱长度、横截面积、厚度）;利用三维测力跑台采集并计算受试者穿着缓冲跑鞋以10 km/h速度跑步时的跟腱负荷特征（跖屈力矩、跟腱力、负载率、冲量、应力等）。结果 与习惯后跟着地跑者相比,习惯前掌着地跑者踝关节跖屈力矩峰值、跟腱力峰值、平均负载率、峰值负载率均显著增加（P＜0.05）,但两组跑者跟腱长度、跟腱横截面积和跟腱厚度差异无统计学意义（P＞0.05）。结论 长期的前掌着地模式可以适应性地提高跟腱在重复性的“拉长-收缩”循环刺激中的力学特性。深入理解跟腱在不同着地方式下的响应,对于跑步爱好者以及运动医学领域中预防跟腱相关损伤具有重要的临床意义。     

跑鞋与着地方式对跑步损伤的影响

长跑是骨骼肌肉系统损伤发病率最高的运动健身项目之一,与跑鞋和着地方式有很大关系。在百链云图书馆和谷歌学术数据库中检索有关跑鞋和着地方式与跑步损伤关系的生物力学研究,最终选择42篇进行文献综述,发表时间为1981~2016年。跑鞋所宣称的缓冲和动作控制的作用并未得到证实,裸足跑作为更自然的跑步方式得到提倡。前脚掌着地的跑步方式对膝关节的损伤更小,但踝关节和跖骨的负荷较大;后跟着地则相反。因此,跑步者应根据自身情况选择适合的跑步方式。但转变跑步方法对跑步者下肢生物力学特征的影响尚未明确,这方面的研究会对跑步者转变跑步方式提出更好的建议。     

Analysis of heel pad tissues mechanics at the heel strike in bare and shod conditions

A combined experimental and numerical approach is used to investigate the interaction phenomena occurring between foot and footwear during the heel strike phase of the gait. Two force platforms are utilised to evaluate the ground reaction forces of a subject in bare and shod walking. The reaction forces obtained from the experimental tests are assumed as loading conditions for the numerical analyses using three dimensional models of the heel region and of the running shoe. The heel pad region, as fat and skin tissues, is described by visco-hyperelastic and fibre-reinforced hyperelastic formulations respectively and bone region by a linear orthotropic formulation. Different elastomeric foams are considered with regard to the outsole, the midsole and the insole layers. The mechanical properties are described by a hyperfoam formulation. The evaluation of the mechanical behaviour of the heel pad tissues at the heel strike in bare and shod conditions is performed considering different combinations of materials for midsole and insole layers. Results allow for the definition of the influence of different material characteristics on the mechanical response of the heel pad region, in particular showing the compressive stress differentiation in the bare and shod conditions.     

Daytime modulation of cortical spreading depression according to blood glucose levels

The plantar surface of the foot senses local pressures during stance and locomotion. These foot loading characteristics may be affected by long distance running. Little is known about the physiological effects of sports-related loading on plantar sensitivity and their relationship with plantar foot loading. The purpose of this study was to investigate the acute effects of long distance running on plantar sensitivity to touch and their relationship with foot loading characteristics. It was hypothesized that plantar sensation would decrease after long distance running and may be related to foot loading characteristics. In 15 middle-aged runners, sensory detection thresholds to light touch and plantar pressures were measured before and after a 10 km run. After the run, no significant changes in sensory perception thresholds were observed so that correlations between foot sensitivity and foot loading could not be calculated. A significant decrease of force-time integrals and maximum forces was demonstrated in the whole foot (−6.2%, p = 0.003; −3.9%, p = 0.001) and the heel (−10.5%, p = 0.003; −8.5%, p = 0.002). Furthermore, maximum force was significantly reduced in the lateral midfoot (−6.4%, p = 0.002). In conclusion, a sub-maximal 10 km running exercise appears to have no significant acute effects on plantar sensitivity, plantar pressure distribution and peak forces.     

The Effect of Foot Strike Pattern on Achilles Tendon Load During Running

In this study we compared Achilles tendon loading parameters during barefoot running among females with different foot strike patterns using open-source computer muscle modeling software to provide dynamic simulations of running. Muscle forces of the gastrocnemius and soleus were estimated from experimental data collected in a motion capture laboratory during barefoot running for 11 runners utilizing a rearfoot strike (RFS) and 8 runners utilizing a non-RFS (NRFS) pattern. Our results show that peak Achilles tendon force occurred earlier in stance phase (p = 0.007), which contributed to a 15% increase in average Achilles tendon loading rate among participants adopting a NRFS pattern (p = 0.06). Stance time, step length, and the estimated number of steps per mile were similar between groups. However, runners with a NRFS pattern experienced 11% greater Achilles tendon impulse each step (p = 0.05) and nearly significantly greater Achilles tendon impulse per mile run (p = 0.06). This difference equates to an additional 47.7 body weights for each mile run with a NRFS pattern. Runners considering a NRFS pattern may want to account for these novel stressors and adapt training programs accordingly.     

即刻改变触地方式对着鞋跑时内侧纵弓在体运动学的影响

目的 探究即刻转换触地方式对着鞋跑步时内侧纵弓在体运动学的影响。 方法 采用高速双平面荧光透视成像系统采集 15 名健康男性跑者即刻改变触地方式前后右足在跑步支撑阶段[跑速:(3±0. 15) m/ s]的荧光图像。根据 CT 图像重建第 1 跖骨和跟骨三维骨骼模型及其局部坐标系,并通过 3D-2D 配准获取内侧纵弓在跑步支撑期的 6 自由度(six degree of freedom,6 DOF) 数据(简化为第 1 跖骨相对跟骨的运动)。 采用一维统计参数映射(statistical parametric mapping,SPM)比较即刻改变触地方式前后内侧纵弓的 6 DOF 运动趋势,并对其特征值进行配对样本 t 检验。 结果 相比后跟跑,即刻前掌跑时,在支撑期的 15% ~ 21% 第 1 跖骨相对跟骨的外移、支撑期 17% ~45% 第 1 跖骨的前移和支撑期的 18% ~ 39% 第 1 跖骨的背屈均显著增加(P<0. 05)。 即刻前掌跑时,第 1 跖骨相对跟骨的前移最大值、背屈最大值、前后平移活动范围及内侧纵弓压缩变化量均显著增加(P<0. 05)。 结论 由习惯后跟跑即刻转换为前掌跑后,内侧纵弓矢状面的形变显著增加,尤其是内侧纵弓的压缩变化量增加约 10% ,可能有助于其弹性能量的储存与释放。     

Ground reaction forces at different speeds of human walking and running

In this study the variation in ground reaction force parameters was investigated with respect to adaptations to speed and mode of progression, and to type of foot-strike. Twelve healthy male subjects were studied during walking (1.0-3.0 m s-1) and running (1.5-6.0 m s-1). The subjects were selected with respect to foot-strike pattern during running. Six subjects were classified as rearfoot strikers and six as forefoot strikers. Constant speeds were accomplished by pacer lights beside an indoor straightway and controlled by means of a photo-electronic device. The vertical, anteroposterior and mediolateral force components were recorded with a force platform. Computer software was used to calculate durations, amplitudes and impulses of the reaction forces. The amplitudes were normalized with respect to body weight (b.w.). Increased speed was accompanied by shorter force periods and larger peak forces. The peak amplitude of the vertical reaction force in walking and running increased with speed from approximately 1.0 to 1.5 b.w. and 2.0 to 2.9 b.w. respectively. The anteroposterior peak force and mediolateral peak-to-peak force increased about 2 times with speed in walking and about 2-4 times in running (the absolute values were on average about 10 times smaller than the vertical). The transition from walking to running resulted in a shorter support phase duration and a change in the shape of the vertical reaction force curve. The vertical peak force increased whereas the vertical impulse and the anteroposterior impulses and peak forces decreased. In running the vertical force showed an impact peak at touch-down among the rearfoot strikers but generally not among the forefoot strikers. The first mediolateral force peak was laterally directed (as in walking) for the rearfoot strikers but medially for the forefoot strikers. Thus, there is a change with speed in the complex interaction between vertical and horizontal forces needed for propulsion and equilibrium during human locomotion. The differences present between walking and running are consequences of fundamental differences in motor strategies between the two major forms of human progression.     

基于三维膝-踝-足有限元模型的足跟痛足底压力生物力学分析

目的通过有限元方法研究鞋垫参数变化对足跟痛患足生物力学机制的影响。方法基于CT图像数据建立足跟痛患者足部、小腿骨骼、腓肠肌及膝关节三维有限元模型,通过改变鞋垫形状、厚度及硬度仿真计算足底压力分布及应力峰值。结果有限元模型足底压力分布与压力测量板的足底压力分布部位大体一致,数值非常接近。与裸足站立相比,穿着平板式、半接触式和全接触式鞋垫时足跟区压力峰值分别下降20.5%、59.2%和38.4%,跖骨头区压力峰值分别下降9.9%、18.1%和46.7%。足跟痛患者足底表面足跟区和跖骨头区域压力峰值均随鞋垫常规厚度的增加而减小,并随硬度的减小而减小。结论鞋垫参数的改变对足底压力产生显著的变化。有限元分析有助于足跟痛病因病理的了解,为临床治疗提供理论基础。