Journal of biomechanics最新文献_第10页

Lower-limb joint work symmetry responses to load carriage and prosthetic foot type during transtibial amputee walking 经胫骨截肢者行走时下肢关节工作对称性对负重和假肢足类型的响应。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-11-01 DOI: 10.1016/j.jbiomech.2025.113047

Stephanie L. Molitor , Krista M. Cyr , Glenn K. Klute , Richard R. Neptune

Individuals with lower-limb amputations are typically prescribed passive prosthetic feet for everyday walking. However, when carrying additional loads, users demonstrate increased reliance on their intact limb which can lead to overuse injuries. Powered prostheses have been shown to reduce compensations during unloaded walking, but their efficacy during load carriage remains unknown. Furthermore, how the position of an added load affects intact limb reliance is not well understood. This study determined (1) how the presence and placement of an added load affects between-limb joint work symmetry for individuals walking with transtibial protheses, and (2) how prosthetic foot type (passive or powered) affects joint work symmetry during load carriage. Kinematic and kinetic data were collected from unilateral transtibial prosthesis users (n = 12) wearing a passive or powered prosthesis while walking with no added load, a 13.6 kg load worn on the front of their torso, or the same load worn on their back. Work symmetry, calculated as the difference between intact-side and prosthesis-side net joint work, was determined for the ankle, knee and hip to quantify intact limb reliance. Ankle and hip work symmetry improved for the Front Load compared to the No Load condition, due to a tradeoff between intact ankle and intact hip demand. Furthermore, ankle work symmetry improved for all load conditions while wearing the powered prosthesis. These results highlight changes in compensatory strategies during different load carriage conditions and encourage the use of powered prostheses to reduce intact limb reliance during activities involving load carriage.

下肢截肢的患者通常会被处方被动假肢脚用于日常行走。然而，当携带额外的负荷时，使用者表现出对完整肢体的依赖，这可能导致过度使用伤害。动力假肢已被证明可以减少无负载行走时的补偿，但其在负重行走时的功效尚不清楚。此外，附加载荷的位置如何影响完整肢体依赖还不是很清楚。本研究确定了(1)附加负荷的存在和放置如何影响使用经胫骨假体行走的个体的肢间关节工作对称性，以及(2)假足类型（被动或动力）如何影响负重过程中关节工作对称性。运动学和动力学数据来自单侧经胫义肢使用者（n = 12），他们在行走时佩戴被动或动力义肢，没有增加负荷，躯干前部负重13.6 kg，背部负重相同。工作对称性，计算为完整侧和假体侧网关节工作的差异，确定踝关节、膝关节和髋关节的工作对称性，以量化完整肢体的依赖。与空载条件相比，由于在完整的脚踝和完整的髋关节需求之间的权衡，前负荷条件下脚踝和髋关节工作的对称性得到了改善。此外，在佩戴动力假肢时，踝关节工作的对称性在所有负载条件下都得到了改善。这些结果强调了在不同负重条件下补偿策略的变化，并鼓励使用动力假肢来减少负重活动中对完整肢体的依赖。

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引用次数: 0

Community challenge towards consensus on characterization of biological tissue: C4Bio’s first findings 社区对生物组织表征共识的挑战：C4Bio的第一个发现

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-10-18 DOI: 10.1016/j.jbiomech.2025.113021

Nele Famaey , Heleen Fehervary , Yoann Lafon , Ali Akyildiz , Silke Dreesen , Karine Bruyère-Garnier , Jean-Marc Allain , Marta Alloisio , Alejandro Aparici-Gil , Chiara Catalano , Fanette Chassagne , Snehal Chokhandre , Kimberly Crevits , Hanneke Crielaard , Eoghan Cunnane , Connor Cunnane , Karen De Leener , Amisha Desai , Rob Driessen , Ahmet Erdemir , Liesbet Geris

This study investigates methodological variability across various expert laboratories worldwide, with regards to characterizing the mechanical properties of biological tissues. Two testing rounds were conducted on the specific use case of uniaxial tensile testing of porcine aorta. In the first round, 24 labs were invited to apply their established methods to assess inter-laboratory variability. This revealed significant methodological diversity and associated variability in the stress–stretch results, underscoring the necessity for a standardized approach.

In the second round, a consensus protocol was collaboratively developed and adopted by 19 labs in an attempt to minimize variability. This involved standardized sample preparation and uniformity in testing protocol, including the use of a common cutting and thickness measurement tool. Despite protocol harmonization, significant variability persisted across labs, which could not be solely attributed to inherent biological differences in tissue samples.

These results illustrate the challenges in unifying testing methods across different research settings, underlining the necessity for further refinement of testing practices. Enhancing consistency in biomechanical experiments is pivotal when comparing results across studies, as well as when using the resulting material properties for in silico simulations in medical research.

本研究调查了世界各地不同专家实验室在描述生物组织机械特性方面的方法差异。针对猪主动脉单轴拉伸试验的具体用例进行了两轮试验。在第一轮中，24个实验室被邀请应用他们建立的方法来评估实验室间的可变性。这揭示了显著的方法多样性和应力拉伸结果的相关可变性，强调了标准化方法的必要性。在第二轮中，19个实验室合作开发并采用了共识协议，以尽量减少可变性。这涉及标准化的样品制备和测试方案的一致性，包括使用通用的切割和厚度测量工具。尽管协议一致，但显著的差异在实验室之间持续存在，这不能仅仅归因于组织样本固有的生物学差异。这些结果说明了在不同的研究环境中统一测试方法的挑战，强调了进一步改进测试实践的必要性。在比较不同研究的结果时，以及在医学研究中使用所得材料特性进行计算机模拟时，增强生物力学实验的一致性至关重要。

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引用次数: 0

Study of lower limb inter-joint coordination during gait of the patients with early-stage osteonecrosis of the femoral head 早期股骨头坏死患者步态中下肢关节间协调的研究。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-11-01 DOI: 10.1016/j.jbiomech.2025.113049

Xianzhi Gao , Muchen Ren , Chenxi Hu , Qing Sun , Jian Jin , Yanfeng Li , Zixin Wang , Jiaqi Zhang , Jianhao Lin , Bo Huo

Previous studies have confirmed that abnormal hip joint mechanics may significantly impact knee joint function. However, traditional gait analysis primarily focuses on the kinematic parameters of individual joints, which to some extent limits its ability to comprehensively reveal the inter-joint coordination patterns and their interaction relationships in the lower limb during gait in patients with hip pain.

In this study, the vector coding (VC) method was employed to quantitatively analyze the inter-joint coordination patterns of the patients with early-stage osteonecrosis of the femoral head (ONFH). The sample consisted of 20 individuals, divided into 2 groups: control (CTRL, n = 10) and ONFH in the early stages (ONFH, n = 10). An infrared motion capture system was used to collect kinematic data of the hip, knee, and ankle joints during gait. Phase analysis of the stance phase was conducted based on coupling angle (CA) and coordination variability.

Results showed that, relative to the CTRL group, the ONFH group exhibited a significantly smaller range of motion (ROM) of the hip joint (46.58%) and the knee joint (41.96%) in the sagittal plane at the middle third of stance, while the ROM of the ankle joint was larger (10.41%) throughout the whole stance phase. Furthermore, the analysis of coordination patterns between the hip-knee, knee-ankle, and hip-ankle joint pairs revealed a distinct distal compensation pattern in the ONFH group. During the middle third of stance, the hip-knee and hip-ankle coordination variability in the ONFH group was significantly higher than that in the CTRL group. This may suggest that the central nervous system (CNS) of patients is developing and refining new inter-joint coordination patterns that adapt to joint dysfunction in a more protective manner to alleviate pain.

These findings provide insights into the unique patterns of the patient-specific inter-joint coordination and compensatory strategies of patients with early-stage ONFH, enhancing the understanding of their gait characteristics and providing crucial biomechanical evidence for designing personalized rehabilitation programs.

既往研究证实，髋关节力学异常可显著影响膝关节功能。然而，传统的步态分析主要关注单个关节的运动学参数，这在一定程度上限制了其全面揭示髋关节疼痛患者步态中下肢关节间协调模式及其相互作用关系的能力。本研究采用向量编码（VC）方法对早期股骨头坏死（ONFH）患者关节间协调模式进行定量分析。样本共20人，分为2组：对照组（CTRL, n = 10）和早期ONFH组（ONFH, n = 10）。红外运动捕捉系统用于收集步态中髋关节、膝关节和踝关节的运动学数据。基于耦合角和配位变异性对姿态相位进行了相位分析。结果显示，与CTRL组相比，ONFH组在站立中三分之一处的髋关节和膝关节矢状面活动度（ROM）明显小于CTRL组（46.58%）和膝关节（41.96%），而踝关节在整个站立阶段的活动度较大（10.41%）。此外，对髋关节-膝关节、膝关节-踝关节和髋关节-踝关节对之间协调模式的分析揭示了ONFH组明显的远端代偿模式。在站立的中间三分之一，ONFH组髋-膝和髋-踝协调变异性显著高于CTRL组。这可能表明患者的中枢神经系统（CNS）正在发展和完善新的关节间协调模式，以更保护的方式适应关节功能障碍，以减轻疼痛。这些发现为早期ONFH患者的关节间协调和代偿策略的独特模式提供了见解，增强了对其步态特征的理解，并为设计个性化康复方案提供了重要的生物力学证据。

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引用次数: 0

Let’s dance −Postural control in ballroom dance Couples: Differences between Profesfsional and amateur dancers 交际舞舞伴的姿势控制：专业舞者与业余舞者的差异。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-12-27 DOI: 10.1016/j.jbiomech.2025.113140

Justyna Michalska, Żaneta Szuplak, Kajetan J. Słomka, Grzegorz Juras

Assessing ballroom dancers as a pair rather than as isolated subjects provides a deeper insight into postural control mechanisms. The aim of this study was to evaluate postural sway in ballroom dancers by comparing the male partner, the female partner, and the dance couple in the standard dance position. Seven international standard ballroom dance couples and fourteen amateur dancers with three months of ballroom training participated voluntarily. Postural sway was assessed using two force plates. Subjects assumed a standard dance position preceded by a short dance phase and were instructed to hold the position for 30 s. Each trial was repeated twice. Center of pressure (COP) parameters were calculated for the anterior–posterior and medio–lateral planes, and a two-way mixed-design ANOVA was applied to assess group and positional effects Significant main effects of group (professional vs. amateur dancers) were found for COP parameters in both planes, with professionals showing higher range of COP (ra COP), root mean square of COP (rms COP), and velocity of COP (v COP) values (p ≤ 0.003, η²p = 0.20–0.50).The effect of condition (male, female, pair) was also significant for most COP variables (p ≤ 0.001, η²p = 0.15–0.41), with female dancers demonstrating lower v COP and Sample entropy (SampEn) values compared to males and pairs. No significant group × position interactions were observed in the anterior–posterior plane (p ≥ 0.06), whereas a significant interaction appeared in the medio–lateral plane for SampEn (p = 0.04, η²p = 0.15). Ballroom dance training influences postural sway. The female partner appears to stabilize the couple, while professional couples exhibit less regular COP signals, suggesting greater automation of postural control compared to amateurs.

将交际舞者作为一对而不是作为孤立的对象进行评估，可以更深入地了解姿势控制机制。本研究的目的是评估交际舞者的姿势摇摆，通过比较男性伴侣，女性伴侣和标准舞蹈姿势的舞蹈夫妇。7对国际标准交际舞组合和14名经过3个月交际舞培训的业余舞者自愿参加。用两个测力板评估体位摇摆。受试者在一个短暂的舞蹈阶段之前采取一个标准的舞蹈姿势，并被要求保持这个姿势30秒。每个试验重复两次。计算前后平面和中外侧平面的压力中心（COP）参数，并采用双向混合设计方差分析评估群体效应和位置效应。两个平面的COP参数均存在专业舞蹈演员和业余舞蹈演员的主效应，专业舞蹈演员的COP （ra COP）、COP均方根（rms COP）和COP速度（v COP）值的范围更高（p≤0.003,η2p = 0.20 ~ 0.50）。条件（男性、女性、伴侣）对大多数COP变量的影响也很显著（p≤0.001,η2p = 0.15-0.41），与男性和伴侣相比，女性舞者的v COP和样本熵（SampEn）值更低。SampEn前后平面无显著组位相互作用（p≥0.06），而中外侧平面有显著组位相互作用（p = 0.04, η2p = 0.15）。交际舞训练影响姿势摇摆。女性伴侣似乎稳定了夫妻关系，而职业伴侣则表现出较少的常规COP信号，这表明与业余伴侣相比，他们的姿势控制更自动化。

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引用次数: 0

Differences in whole-body angular momentum between treadmill and overground walking 跑步机与地上步行的全身角动量差异。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-12-11 DOI: 10.1016/j.jbiomech.2025.113123

Florian Etheve, Jérémie Begue, Margaux Levasseur, Ophélie Larivière, Eve Charbonneau, Teddy Caderby

Whole-body angular momentum (H) is a relevant biomechanical marker of dynamic balance during walking. Although treadmill walking is commonly used for gait analysis and rehabilitation, it results in notable spatiotemporal and kinetic differences compared to overground walking. However, its specific effects on H remain unclear. This study aimed to investigate differences in H between treadmill and overground walking in able-bodied adults. Fourteen healthy adults walked at their preferred speed under two randomized conditions: 1) treadmill walking and 2) overground walking on a 7-meter walkway. H was computed in the sagittal, frontal, and transverse planes using 3D motion capture data. Amplitude (peak-to-peak range) and temporal evolution of H were analyzed and compared across walking conditions. Spatiotemporal gait parameters were also calculated. Compared to overground walking, treadmill walking was associated with a significantly reduced H range (p < 0.001) and an altered temporal evolution of H across all planes. These alterations were accompanied by spatiotemporal modifications, including increased cadence and step width, as well as reduced step length and stride length during treadmill walking. These changes may reflect a more conservative gait strategy to enhance balance control during treadmill walking. These findings highlight that H differs between treadmill and overground walking, and that caution should be exercised when generalizing results obtained on the treadmill to overground walking.

全身角动量(H)是行走过程中动态平衡的相关生物力学指标。尽管跑步机行走常用于步态分析和康复，但与地上行走相比，它会导致显著的时空和动力学差异。然而，它对H的具体影响尚不清楚。本研究旨在调查健全人在跑步机和地上行走时H值的差异。14名健康成年人在两种随机条件下以自己喜欢的速度行走：1)在跑步机上行走；2)在7米长的人行道上行走。利用三维运动捕捉数据计算矢状面、额状面和横切面的H。分析和比较了不同步行条件下H的振幅（峰间范围）和时间演变。同时计算了时空步态参数。与地面行走相比，跑步机行走与H范围显著减小相关(p

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引用次数: 0

Iliopsoas strengthening increases hip joint forces during gait: A simulation study 髂腰肌加强增加髋关节力量在步态：模拟研究。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-11-14 DOI: 10.1016/j.jbiomech.2025.113076

Madeline Grosklos , Jay R Patel , Cara L Lewis , Siddharth Fernandes , Stephanie Di Stasi

Femoroacetabular impingement syndrome (FAIS) is a common source of hip pain in young, active individuals and treatments have yielded variable success rates. Weakness of the hip flexors in individuals with FAIS often fails to be resolved during treatment and has been correlated to worse patient reported outcomes and joint damage. This study used musculoskeletal modeling to investigate the differences in iliacus and psoas force production and JCFs during walking between individuals with FAIS and healthy controls (HCs) and to simulate hip flexor strength and weakness in participants and evaluate the resulting changes in JCFs during walking. Five conditions of iliacus and psoas strength were evaluated: 50%, 75%, 100%, 125%, and 150% of the model’s default strength. Statistical parametric mapping was used to compare outcomes between groups and between flexor strength conditions. There were no significant differences between the FAIS and HC groups. Increased flexor strength caused higher resultant JCFs and directional components of the JCF throughout the gait cycle. Decreased flexor strength caused lower JCFs across most of the gait cycle; there was no difference in the resultant or superior JCF during preswing and the medial JCF was higher during a small percentage of preswing. These findings indicate that increasing hip flexor strength may have a more uniform effect on JCFs while decreasing flexor strength results in more varied effects between individuals and across the gait cycle.

股髋臼撞击综合征（FAIS）是年轻活跃人群髋关节疼痛的常见原因，治疗成功率各不相同。FAIS患者的髋屈肌无力在治疗过程中往往无法得到解决，这与患者报告的不良结果和关节损伤有关。本研究使用肌肉骨骼模型来研究FAIS患者和健康对照组（hc）在行走过程中髂肌和腰肌力量产生和联合关节纤维的差异，并模拟参与者的髋屈肌力量和无力，评估行走过程中联合关节纤维的变化。评估髂肌和腰肌强度的五种情况：模型默认强度的50%、75%、100%、125%和150%。统计参数映射用于比较组间和屈肌强度条件之间的结果。FAIS组与HC组间无显著差异。在整个步态周期中，屈肌强度的增加导致更高的JCF和JCF的方向性成分。在大多数步态周期中，屈肌强度降低导致jcf降低；在按压过程中产生的或优越的JCF没有差异，而在一小部分按压过程中，内侧JCF更高。这些研究结果表明，增加髋屈肌力量可能对jcf有更均匀的影响，而减少屈肌力量会在个体和整个步态周期中产生更多不同的影响。

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引用次数: 0

Influence of carbon-plated running shoes and fatigue on lower limb biomechanics 镀碳跑鞋和疲劳对下肢生物力学的影响

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-12-05 DOI: 10.1016/j.jbiomech.2025.113102

Xiangdong Luo , Ruijiao Liu , Bo Li

This study aimed to investigate the effects of shoe longitudinal bending stiffness and fatigue state on lower limb joint biomechanics and impact loading characteristics during running. Sixteen participants were tested using a 3D motion capture system and force platforms to collect and analyze kinematic and kinetic data of the metatarsophalangeal, ankle, knee, and hip joints, as well as the average vertical loading rate (VALR) of ground reaction force, under two footwear conditions before and after induced running fatigue. Carbon-plated shoes significantly restricted metatarsophalangeal joint flexion, while hip transverse plane range of motion was notably affected by fatigue. Fatigue primarily reduced knee joint flexion–extension moment and stiffness, increased ankle pronation moment, and elevated VALR. A significant interaction effect between fatigue and shoe type was observed on VALR, with non-carbon shoes demonstrating superior shock attenuation under fatigue. Shoe structure and fatigue state significantly influence multi-joint coordination and control in the lower limbs. This study supports the “distal restriction–proximal compensation” mechanism, suggesting that while carbon-plated shoes enhance propulsion efficiency, the restricted distal mobility, especially under fatigue, increases compensatory loading and injury risk in proximal joints.

本研究旨在探讨跑鞋纵向弯曲刚度和疲劳状态对跑步时下肢关节生物力学和冲击载荷特性的影响。使用3D运动捕捉系统和受力平台对16名参与者进行测试，收集和分析在诱导跑步疲劳前后两种鞋类条件下跖趾、踝关节、膝关节和髋关节的运动学和动力学数据，以及地面反作用力的平均垂直加载率（VALR）。碳板鞋明显限制跖指关节屈曲，而髋横平面运动范围明显受疲劳影响。疲劳主要降低膝关节屈伸力矩和刚度，增加踝关节旋前力矩，升高VALR。疲劳与鞋型之间存在显著的交互作用，非碳鞋在疲劳条件下表现出更好的冲击衰减。鞋的结构和疲劳状态对下肢多关节的协调和控制有显著影响。该研究支持“远端限制-近端补偿”机制，表明虽然碳涂层鞋提高了推进效率，但远端受限的活动能力，特别是在疲劳情况下，增加了近端关节的代偿负荷和损伤风险。

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引用次数: 0

Macroscopic and microscopic biomechanical analysis of mineralized spheroids derived by mesenchymal stem cells 间充质干细胞矿化球体的宏观和微观生物力学分析。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-11-27 DOI: 10.1016/j.jbiomech.2025.113088

Takashi Inagaki , Jeonghyun Kim , Eijiro Maeda , Taiji Adachi , Takeo Matsumoto

Three-dimensional cultures that simulate bone formation in vitro are promising approaches for elucidating the mineralization process involved in osteogenesis. In this study, we performed a multiscale analysis of spheroids derived from human mesenchymal stem cells. We quantified morphological changes and mechanical conditions from microscale local stiffness to macroscale overall stiffness and viscoelastic/plastic behaviors as mineralization progressed. Specifically, we evaluated how the overall mechanical properties (e.g., Young’s modulus), mechanical behaviors (e.g., elastic or viscoelastic behaviors), and local mechanical environments (e.g., Young’s modulus and morphological distributions) evolve during the long-term culture of spheroids derived from human mesenchymal stem cells. After 35 days of culture, we observed progression of mineralization within the spheroids, increased stiffness and plastic deformation at the macroscopic level assessed by uniaxial compression tests. A greater heterogeneity in mechanical properties and environments at the microscopic level was observed using atomic force microscopy. These findings indicate changes in mechanical properties and behavior during the in vitro bone formation process, suggesting that the mineralization within spheroids is highly heterogeneous. This study elucidates the complexity of the mineralization process in three-dimensional culture models and, for the first time, evaluates this process from a mechanical perspective, providing new insights for future bone regenerative medicine research utilizing three-dimensional culture models.

体外模拟骨形成的三维培养是阐明参与骨形成的矿化过程的有前途的方法。在这项研究中，我们对来自人间充质干细胞的球体进行了多尺度分析。随着矿化的进行，我们量化了从微观尺度的局部刚度到宏观尺度的整体刚度和粘弹/塑性行为的形态变化和力学条件。具体来说，我们评估了在人类间充质干细胞衍生的球体的长期培养过程中，整体力学性能（如杨氏模量）、力学行为（如弹性或粘弹性行为）和局部力学环境（如杨氏模量和形态分布）是如何演变的。经过35天的培养，我们观察到球体内矿化的进展，单轴压缩试验评估了宏观水平上刚度和塑性变形的增加。在微观水平上，使用原子力显微镜观察到机械性能和环境的更大异质性。这些发现表明在体外骨形成过程中力学性能和行为的变化，表明球体内的矿化是高度不均匀的。本研究阐明了三维培养模型中矿化过程的复杂性，并首次从力学角度对这一过程进行了评价，为未来利用三维培养模型进行骨再生医学研究提供了新的思路。

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引用次数: 0

The effect of component offset on acromion and scapular spine strains following reverse total shoulder arthroplasty: An ex-vivo shoulder motion study 反向全肩关节置换术后构件偏移对肩峰和肩胛骨拉伤的影响：一项离体肩关节运动研究。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-12-06 DOI: 10.1016/j.jbiomech.2025.113112

David T. Axford , Robert Potra , Richard Appleyard , Janos Tomka , Antonio Arenas-Miquelez , Desmond J. Bokor , Louis M. Ferreira , Sumit Raniga

The effects of component offset in reverse total shoulder arthroplasty (rTSA) on acromion and scapular spine strains are not well understood, and no comparison of strain patterns between the native and implanted shoulder exists. This study investigated the effects of humerus distalization, humerus lateralization, glenosphere lateralization, and humerus-to-glenosphere lateralization ratio in rTSA on acromion and scapular spine strains during simulated unconstrained shoulder motion and compared the observed strain patterns to the native condition. Seven cadaveric specimens were tested on a shoulder simulator which performed scapular plane abduction and internal-external rotation. Maximum principal strain was measured in four clinically relevant regions according to the Levy classification system using strain gauge rosettes. Overall, rTSA conditions had higher strains than the native condition at low elevation (p < 0.05) but not at high elevation. During scapular plane abduction, strain peaked at low elevation for all reverse conditions, but at high elevation angles in the native condition. Strain increased significantly with humerus distalization in Levy 3A (p = 0.038), while strain decreased significantly in all regions with humerus lateralization (p ≤ 0.049). Isolated glenosphere lateralization had no effect on scapula strains (p ≥ 0.162) while humerus-sided lateralization resulted in significantly less strain than combined humerus and glenosphere lateralization (p ≤ 0.015). RTSA alters the strain patterns on the acromion and scapular spine from those observed in the native shoulder. In addition, component offset had significant effects on scapula strains demonstrating that implant configuration likely has an influence on the occurrence of acromion and scapular spine fractures.

逆行全肩关节置换术（rTSA）中构件偏移对肩峰和肩胛骨应变的影响尚不清楚，也没有对原生肩关节和植入肩关节的应变模式进行比较。本研究研究了rTSA中肱骨远端化、肱骨侧化、关节盂侧化和肱骨-关节盂侧化比例对模拟无约束肩部运动中肩峰和肩胛骨应变的影响，并将观察到的应变模式与自然状态进行了比较。7具尸体标本在肩胛骨平面外展和内外旋转的肩部模拟器上进行了测试。最大主应变测量在四个临床相关区域根据列维分类系统使用应变计玫瑰花。总体而言，低海拔rTSA条件下的菌株数量高于自然条件(p

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引用次数: 0

The rate of force development − in cat and rat medial gastrocnemius motor units – An interspecies comparison 猫和大鼠内侧腓肠肌运动单元的力发展速度-种间比较

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2026-01-01 Epub Date: 2025-10-21 DOI: 10.1016/j.jbiomech.2025.113024

Bartosz Wasicki , Maja Krauze , Piotr Krutki , Marcin Bączyk , Jan Celichowski , Hanna Drzymała-Celichowska

The rate of force development (RFD, calculated as dF/dt, is one of the most important parameters of force developed during motor unit (MU) or muscle contractions. However, it is not obvious to what extent it is determined by body mass, muscle size, and contraction force, and to what extent it reflects the properties of intramuscular contractile proteins and biomechanical relationships. Therefore, this study compared the RFD between cat and rat MUs, which have considerably different contraction time and force properties. It performed in vivo experiments on functionally isolated MUs, divided into slow (S), fast-resistant (FR), and fast-fatigable (FF) types. The twitch and tetanus RFD gradually increased from S to FF MUs in both species and correlated strongly with twitch and tetanus forces, respectively. The tetanus RFD of S, FR, and FF MUs did not differ significantly between cats and rats (1.2 vs. 0.89, 4.59 vs. 4.06, and 13.2 vs. 10.35 N/s, respectively; p > 0.05). Interspecies differences were observed only for the twitch RFD of S and FR MUs, being significantly lower in cats than in rats (p < 0.001). These findings indicate that the RFD is predominantly related to myosin properties, and interspecies differences in the twitch RFD of S and FR MUs have a biomechanical basis.

力发展率（RFD，以dF/dt计算）是运动单元（MU）或肌肉收缩过程中力发展的最重要参数之一。然而，它在多大程度上是由体重、肌肉大小和收缩力决定的，在多大程度上反映了肌内收缩蛋白的特性和生物力学关系，目前还不清楚。因此，本研究比较了猫和大鼠小鼠的RFD，它们的收缩时间和受力特性有很大的不同。对功能分离的小鼠进行了体内实验，分为慢速型(S)、快耐型（FR）和快疲劳型（FF）。两种动物的抽动力和破伤风力RFD从S到FF mu逐渐增大，且分别与抽动力和破伤风力呈强相关。S、FR和FF mu的破伤风RFD在猫和大鼠之间无显著差异（分别为1.2 vs. 0.89、4.59 vs. 4.06、13.2 vs. 10.35 N/ S; p > 0.05）。仅在S和FR MUs的抽搐RFD上观察到种间差异，猫的RFD显著低于大鼠（p < 0.001）。这些发现表明RFD主要与肌球蛋白特性有关，S和FR mu的抽搐RFD的种间差异具有生物力学基础。

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