Journal of biomechanics最新文献_第6页

A critical orientation on muscle marker placement: Multiple angles to consider 肌肉标记放置的关键方向：需要考虑多个角度

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-17 DOI: 10.1016/j.jbiomech.2025.113137

Cameron R. Taylor , Rachel C. Fleming , William H. Clark , Richard L. Marsh , Thomas J. Roberts

The muscles that drive animal and human movement are spatially rich in three-dimensional deformation, yet capturing this complexity in vivo is extremely challenging. As a result, much of our research relies on a single metric of muscle geometry: fascicle length. A variety of muscle marker technologies, such as sonomicrometry, fluoromicrometry, and magnetomicrometry, have enabled us to monitor muscle fascicle lengths over time. Due to the complex nature of muscle deformation, the three-dimensional placement of these muscle markers is important. We aimed to determine just how important that muscle marker placement is. To this end, we simultaneously monitored muscle long-axis distances and fascicle lengths under a variety of muscle actions in an avian gastrocnemius. We found that muscle long-axis distances did not reliably correspond to fascicle lengths, even occasionally showing inverted length changes, and we found that the muscle long-axis distances lacked a consistent relationship with fascicle lengths and even with each other. In summary, we showed that fascicle length cannot in general be predicted from arbitrary muscle tissue length. Our results suggest that improper placement of muscle markers for tracking fascicle lengths cannot be corrected for in post-processing, and we strongly encourage the biomechanist to take special care in placing each muscle marker pair along a fascicle when studying or otherwise monitoring muscle fascicle lengths.

驱动动物和人类运动的肌肉在空间上具有丰富的三维变形，然而在体内捕捉这种复杂性是极具挑战性的。因此，我们的大部分研究都依赖于肌肉几何的单一度量：肌束长度。各种肌肉标记技术，如声测、荧光测和磁测，使我们能够监测肌肉束长度随时间的变化。由于肌肉变形的复杂性，这些肌肉标记的三维位置很重要。我们的目标是确定肌肉标记位置的重要性。为此，我们同时监测了鸟类腓肠肌在各种肌肉运动下的肌肉长轴距离和肌束长度。我们发现肌肉长轴距离与肌束长度的对应并不可靠，甚至偶尔会出现长度倒转的变化，我们发现肌肉长轴距离与肌束长度之间甚至彼此之间缺乏一致的关系。综上所述，我们表明一般不能从任意肌肉组织长度预测肌束长度。我们的研究结果表明，追踪肌束长度的肌肉标记物放置不当无法在后处理中纠正，我们强烈建议生物力学家在研究或以其他方式监测肌束长度时，特别注意沿肌束放置每对肌肉标记物。

{"title":"A critical orientation on muscle marker placement: Multiple angles to consider","authors":"Cameron R. Taylor , Rachel C. Fleming , William H. Clark , Richard L. Marsh , Thomas J. Roberts","doi":"10.1016/j.jbiomech.2025.113137","DOIUrl":"10.1016/j.jbiomech.2025.113137","url":null,"abstract":"<div><div>The muscles that drive animal and human movement are spatially rich in three-dimensional deformation, yet capturing this complexity <em>in vivo</em> is extremely challenging. As a result, much of our research relies on a single metric of muscle geometry: fascicle length. A variety of muscle marker technologies, such as sonomicrometry, fluoromicrometry, and magnetomicrometry, have enabled us to monitor muscle fascicle lengths over time. Due to the complex nature of muscle deformation, the three-dimensional placement of these muscle markers is important. We aimed to determine just <em>how</em> important that muscle marker placement is. To this end, we simultaneously monitored muscle long-axis distances and fascicle lengths under a variety of muscle actions in an avian gastrocnemius. We found that muscle long-axis distances did not reliably correspond to fascicle lengths, even occasionally showing inverted length changes, and we found that the muscle long-axis distances lacked a consistent relationship with fascicle lengths and even with each other. In summary, we showed that fascicle length cannot in general be predicted from arbitrary muscle tissue length. Our results suggest that improper placement of muscle markers for tracking fascicle lengths cannot be corrected for in post-processing, and we strongly encourage the biomechanist to take special care in placing each muscle marker pair along a fascicle when studying or otherwise monitoring muscle fascicle lengths.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113137"},"PeriodicalIF":2.4,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hindlimb unloading results in accelerated bone loss compared to aging in select bone compartments of female murine femurs 与雌性小鼠股骨部分骨区老化相比，后肢卸荷导致骨丢失加速。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-16 DOI: 10.1016/j.jbiomech.2025.113134

Steven J. Meas, Gabriella M. Daire, Evan G. Buettmann, Henry J. Donahue

Disuse- and age-induced bone loss both increase skeletal fragility and therefore are important to public health. There is a strong research foundation in each type of bone loss individually, but no study has directly compared the two in a controlled setting in female mice. In this study, we compare skeletally mature 6-month-old female mice subjected to hindlimb unloading for three weeks (HLU), to aged 22-month-old female mice to identify similarities and differences.

Bone microarchitecture results indicated that there are compartmental differences that change in response to HLU and aging, but HLU demonstrates an intermediate phenotype between control groups of age-matched controls and aged mice. Similar results were observed biomechanically after three-point bending, with HLU demonstrating an intermediate phenotype in bone strength compared to aging. On histological examination, there was a significantly higher level of bone marrow adiposity after HLU greater than aging. There was a higher amount of DNA damage markers such as yH2Ax when comparing aged to young samples, but this was not seen with HLU. These findings indicate that disuse- and aging in bone show some phenotypic similarities but proceed along different timelines.

废弃和年龄引起的骨质流失都会增加骨骼的脆弱性，因此对公众健康很重要。每一种类型的骨质流失都有很强的研究基础，但没有研究在雌性小鼠的控制环境中直接比较这两种类型。在这项研究中，我们比较了骨骼成熟的6月龄雌性小鼠进行后肢卸荷三周（HLU）和22月龄雌性小鼠，以确定异同。骨微结构结果表明，在HLU和衰老的反应中存在区室差异，但HLU在年龄匹配的对照组和老年小鼠之间表现为中间表型。在三点弯曲后观察到类似的生物力学结果，与衰老相比，HLU在骨强度方面表现出中等表型。组织学检查显示，HLU后骨髓脂肪水平明显高于衰老。与年轻样本相比，衰老样本中有更多的DNA损伤标记，如yH2Ax，但在HLU中没有看到这种情况。这些发现表明，骨的废弃和老化显示出一些表型上的相似性，但沿着不同的时间线进行。

{"title":"Hindlimb unloading results in accelerated bone loss compared to aging in select bone compartments of female murine femurs","authors":"Steven J. Meas, Gabriella M. Daire, Evan G. Buettmann, Henry J. Donahue","doi":"10.1016/j.jbiomech.2025.113134","DOIUrl":"10.1016/j.jbiomech.2025.113134","url":null,"abstract":"<div><div>Disuse- and age-induced bone loss both increase skeletal fragility and therefore are important to public health. There is a strong research foundation in each type of bone loss individually, but no study has directly compared the two in a controlled setting in female mice. In this study, we compare skeletally mature 6-month-old female mice subjected to hindlimb unloading for three weeks (HLU), to aged 22-month-old female mice to identify similarities and differences.</div><div>Bone microarchitecture results indicated that there are compartmental differences that change in response to HLU and aging, but HLU demonstrates an intermediate phenotype between control groups of age-matched controls and aged mice. Similar results were observed biomechanically after three-point bending, with HLU demonstrating an intermediate phenotype in bone strength compared to aging. On histological examination, there was a significantly higher level of bone marrow adiposity after HLU greater than aging. There was a higher amount of DNA damage markers such as yH2Ax when comparing aged to young samples, but this was not seen with HLU. These findings indicate that disuse- and aging in bone show some phenotypic similarities but proceed along different timelines.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113134"},"PeriodicalIF":2.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145819375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessment of fluid ingress into the graft-host interface of osteochondral grafts and synthetic scaffolds under cyclic axial loading in a tibio-femoral model 在胫骨-股骨模型中循环轴向载荷下骨软骨移植物和合成支架移植物-宿主界面的流体进入评估。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-16 DOI: 10.1016/j.jbiomech.2025.113132

Lara Esquivel , Mingjing Zhang , Gavin Day , Marlène Mengoni , Hazel Fermor , Chaozong Liu , Ruth Wilcox

This study developed an in vitro method to evaluate fluid ingress into the graft-host interface of osteochondral grafts and mimetic constructs and the risk of graft subsidence, using porcine and ovine tibio-femoral models, to investigate mechanisms associated with cyst development. Distal femurs were implanted with two osteochondral grafts or mimetic constructs. One was implanted axially with the loading direction at the point of initial contact of the femur and tibia (“loaded graft”); another on an unloaded portion of the opposite condyle (“unloaded graft”). During testing under a uniaxial cyclic loading regime, the specimens were housed in a contrast medium. Micro-CT scans taken before and after testing allowed the movement of the contrast fluid to be visualized. Fluid ingress was quantified by comparing the greyscale distribution across line profiles between the μCT scans. Ingress was calculated at six sites of interest: two at each graft site (“graft-host interface”, “graft centre”), one through “loaded host bone”, and one through “unloaded host bone”. Graft presence and loading were key factors to promote fluid ingress (p = 0.001). Fluid ingress at loaded graft-host interfaces relative to the unloaded host bone of porcine-in-porcine was 2.4 ± 8.9 mm, porcine-in-ovine was 9.9 ± 3.1 mm, and mimetic constructs-inporcine was 3.6 ± 3.8 mm. A mismatch in material properties between the graft and host bone promoted ingress, driven by host bone quality. Subchondral bone damage and fluid pooling below grafts was detectable from μCT images. Results indicate host bone quality should be considered when assessing a patient’s suitability for surgery.

本研究开发了一种体外方法来评估骨软骨移植物和模拟构建物的移植物-宿主界面的液体侵入以及移植物下沉的风险，使用猪和羊的胫骨-股模型来研究囊肿发展的相关机制。股骨远端植入两个骨软骨移植物或模拟结构。一个在股骨和胫骨的初始接触点沿加载方向轴向植入（“加载移植物”）；另一个在对侧髁的卸载部分（“卸载移植物”）。在测试中，在单轴循环加载制度下，试样被安置在对比介质中。在测试前后进行微ct扫描，可以看到造影剂的运动情况。通过比较各μCT扫描线剖面上的灰度分布来定量流体进入。在六个感兴趣的位置计算进入：每个移植物位置两个（“移植物-宿主界面”，“移植物中心”），一个通过“加载宿主骨”，一个通过“卸载宿主骨”。移植物的存在和负荷是促进液体进入的关键因素（p = 0.001）。加载的移植物-宿主界面相对于未加载的宿主骨，猪-猪为2.4±8.9 mm，猪-羊为9.9±3.1 mm，模拟结构-猪为3.6±3.8 mm。在宿主骨质量的驱动下，移植物和宿主骨之间材料特性的不匹配促进了移植物的进入。μCT图像显示软骨下骨损伤和移植物下积液。结果表明，在评估患者是否适合手术时应考虑宿主骨质量。

{"title":"Assessment of fluid ingress into the graft-host interface of osteochondral grafts and synthetic scaffolds under cyclic axial loading in a tibio-femoral model","authors":"Lara Esquivel , Mingjing Zhang , Gavin Day , Marlène Mengoni , Hazel Fermor , Chaozong Liu , Ruth Wilcox","doi":"10.1016/j.jbiomech.2025.113132","DOIUrl":"10.1016/j.jbiomech.2025.113132","url":null,"abstract":"<div><div>This study developed an <em>in vitro</em> method to evaluate fluid ingress into the graft-host interface of osteochondral grafts and mimetic constructs and the risk of graft subsidence, using porcine and ovine tibio-femoral models, to investigate mechanisms associated with cyst development. Distal femurs were implanted with two osteochondral grafts or mimetic constructs. One was implanted axially with the loading direction at the point of initial contact of the femur and tibia (“loaded graft”); another on an unloaded portion of the opposite condyle (“unloaded graft”). During testing under a uniaxial cyclic loading regime, the specimens were housed in a contrast medium. Micro-CT scans taken before and after testing allowed the movement of the contrast fluid to be visualized. Fluid ingress was quantified by comparing the greyscale distribution across line profiles between the μCT scans. Ingress was calculated at six sites of interest: two at each graft site (“graft-host interface”, “graft centre”), one through “loaded host bone”, and one through “unloaded host bone”. Graft presence and loading were key factors to promote fluid ingress (p = 0.001). Fluid ingress at loaded graft-host interfaces relative to the unloaded host bone of porcine-in-porcine was 2.4 ± 8.9 mm, porcine-in-ovine was 9.9 ± 3.1 mm, and mimetic constructs-inporcine was 3.6 ± 3.8 mm. A mismatch in material properties between the graft and host bone promoted ingress, driven by host bone quality. Subchondral bone damage and fluid pooling below grafts was detectable from μCT images. Results indicate host bone quality should be considered when assessing a patient’s suitability for surgery.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113132"},"PeriodicalIF":2.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145781345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Muscle synergy analysis of short-term adaptation to arm-support exoskeletons during pseudo-static and dynamic overhead tasks 在伪静态和动态头顶任务中短期适应臂支撑外骨骼的肌肉协同分析。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-15 DOI: 10.1016/j.jbiomech.2025.113135

Hanjun Park , Maury A. Nussbaum

Occupational arm-support exoskeletons (ASEs) can reduce shoulder muscle activity during overhead work, but their effects on muscle synergy structure and temporal activation remain limited. We examined the effects of using three different exoskeletons on muscle synergies during simulated overhead tasks. Muscle activity from 18 participants (gender-balanced) performing both pseudo-static and dynamic tasks across 24 conditions (three ASEs and a control condition) was analyzed using non-negative matrix factorization to extract synergy number, structure, and activation coefficients. Dynamic tasks recruited more muscle synergies (interquartile range: 2–5) than pseudo-static tasks (interquartile range: 1–3), with some task combinations showing modest increases with ASE use compared to the control condition. Synergy structure and temporal activation were generally similar across interventions (mean cosine similarity 0.74–0.92), but certain ASE-task combinations produced significant local changes in synergy structure. Using exoskeletons generally altered muscle weightings, shifting from primary arm-elevating and shoulder-stabilizing muscles toward modules involving neck and back muscles, suggesting compensatory strategies for device-imposed biomechanical demands. Activation time courses remained highly similar across most interventions during pseudo-static tasks, though dynamic tasks showed reduced peak magnitude with exoskeleton use. Our results indicate that while modular motor control is largely preserved with ASE use, device- and task-specific adaptations in synergy structure and temporal activation can occur. Future research should explore how ASE design features influence neuromuscular strategies and assess long-term adaptation of muscle synergies in occupational settings.

职业性臂支撑外骨骼（ase）可以减少头顶工作时肩部肌肉的活动，但其对肌肉协同结构和颞部激活的影响仍然有限。我们研究了在模拟头顶任务中使用三种不同外骨骼对肌肉协同作用的影响。18名参与者（性别平衡）在24个条件下（三个ase和一个对照条件）执行伪静态和动态任务，使用非负矩阵分解法分析肌肉活动，以提取协同数、结构和激活系数。动态任务比伪静态任务（四分位数范围：1-3）调动了更多的肌肉协同作用（四分位数范围：2-5），与对照条件相比，一些任务组合在使用ASE时显示出适度的增加。协同结构和时间激活在不同干预中基本相似（平均余弦相似度为0.74-0.92），但某些ase任务组合在协同结构上产生了显著的局部变化。使用外骨骼通常会改变肌肉的重量，从主要的手臂提升和肩部稳定肌肉转向涉及颈部和背部肌肉的模块，这表明了对设备施加的生物力学需求的补偿策略。在伪静态任务期间，激活时间过程在大多数干预措施中保持高度相似，尽管动态任务显示外骨骼使用降低了峰值幅度。我们的研究结果表明，虽然模块化的电机控制在很大程度上保留了ASE的使用，但协同结构和时间激活的设备和任务特异性适应可能会发生。未来的研究应探讨ASE设计特征如何影响神经肌肉策略，并评估职业环境下肌肉协同作用的长期适应性。

{"title":"Muscle synergy analysis of short-term adaptation to arm-support exoskeletons during pseudo-static and dynamic overhead tasks","authors":"Hanjun Park , Maury A. Nussbaum","doi":"10.1016/j.jbiomech.2025.113135","DOIUrl":"10.1016/j.jbiomech.2025.113135","url":null,"abstract":"<div><div>Occupational arm-support exoskeletons (ASEs) can reduce shoulder muscle activity during overhead work, but their effects on muscle synergy structure and temporal activation remain limited. We examined the effects of using three different exoskeletons on muscle synergies during simulated overhead tasks. Muscle activity from 18 participants (gender-balanced) performing both pseudo-static and dynamic tasks across 24 conditions (three ASEs and a control condition) was analyzed using non-negative matrix factorization to extract synergy number, structure, and activation coefficients. Dynamic tasks recruited more muscle synergies (interquartile range: 2–5) than pseudo-static tasks (interquartile range: 1–3), with some task combinations showing modest increases with ASE use compared to the control condition. Synergy structure and temporal activation were generally similar across interventions (mean cosine similarity 0.74–0.92), but certain ASE-task combinations produced significant local changes in synergy structure. Using exoskeletons generally altered muscle weightings, shifting from primary arm-elevating and shoulder-stabilizing muscles toward modules involving neck and back muscles, suggesting compensatory strategies for device-imposed biomechanical demands. Activation time courses remained highly similar across most interventions during pseudo-static tasks, though dynamic tasks showed reduced peak magnitude with exoskeleton use. Our results indicate that while modular motor control is largely preserved with ASE use, device- and task-specific adaptations in synergy structure and temporal activation can occur. Future research should explore how ASE design features influence neuromuscular strategies and assess long-term adaptation of muscle synergies in occupational settings.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113135"},"PeriodicalIF":2.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145810048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of custom-made foot orthoses on lower limb kinematics and kinetics during step-up and step-down tasks in individuals with progressive collapsing foot deformity 定制足部矫形器对进行性塌陷足畸形患者在上升和下降过程中下肢运动学和动力学的影响。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-15 DOI: 10.1016/j.jbiomech.2025.113136

Ahmed Dami , Eléna Payen Schalkens , Tahereh Ghabdian , Nader Farahpour , Pier-Luc Isabelle , Gabriel Moisan

Progressive collapsing foot deformity (PCFD) is a debilitating condition causing significant biomechanical impairments. Custom-made foot orthoses (FOs) provide a non-invasive treatment by supporting the medial longitudinal arch and improving foot and ankle biomechanics. While previous studies on PCFD have predominantly investigated the biomechanical effects of FOs during walking, their impact on more demanding dynamic tasks remains unclear. This study aimed to investigate the effects of custom-made FOs on lower limb kinematics and kinetics during step-up (SU), step-down (SD), and step-down on a medially inclined surface (SDI) in individuals with PCFD. Twenty participants with flexible PCFD performed SU, SD and SDI tasks with and without FOs. Hip, knee, ankle and midfoot angles and moments were calculated and compared across conditions using one-dimensional statistical parametric mapping. Custom-made FOs reduced midfoot dorsiflexion across all tasks (SU: 4.9°; SD: 4.6°; SDI: 5.4°) and decreased ankle eversion during SU (2.9°) and SD (3.5°), but the reduction during SDI was non-significant. Custom FOs also reduced ankle inversion moments while increasing knee abduction moments during all step tasks. These findings indicate that custom-made FOs effectively support the medial longitudinal arch and limit foot pronation during dynamic movements, likely reducing loading on the medial ankle structures. However, their biomechanical efficacy was less pronounced when individuals with PCFD landed on a medially inclined surface. These findings highlight FOs potential as a conservative intervention for flexible PCFD to improve lower limb biomechanics.

进行性塌陷足畸形（PCFD）是一种导致显著生物力学损伤的衰弱性疾病。定制足部矫形器（FOs）通过支持内侧纵弓和改善足部和踝关节生物力学提供非侵入性治疗。虽然先前关于PCFD的研究主要是研究行走过程中FOs的生物力学效应，但它们对更高要求的动态任务的影响尚不清楚。本研究旨在探讨定制FOs对PCFD患者在升压（SU）、降压（SD）和中斜面降压（SDI）过程中下肢运动学和动力学的影响。20名具有灵活PCFD的参与者在有FOs和没有FOs的情况下执行SU、SD和SDI任务。使用一维统计参数映射计算和比较不同条件下髋关节、膝关节、踝关节和足中部的角度和力矩。定制的FOs在所有任务中减少了足中部背屈（SU: 4.9°；SD: 4.6°；SDI: 5.4°），并在SU（2.9°）和SD（3.5°）期间减少了踝关节外翻，但SDI期间的减少不显著。自定义FOs也减少了踝关节反转时刻，同时增加了所有步骤任务中的膝关节外展时刻。这些研究结果表明，定制的FOs有效地支持内侧纵弓，并在动态运动中限制足部内旋，可能减少内侧踝关节结构的负荷。然而，当PCFD患者降落在中间倾斜的表面时，它们的生物力学效果不那么明显。这些发现强调了FOs作为柔性PCFD的保守干预措施改善下肢生物力学的潜力。

{"title":"Effects of custom-made foot orthoses on lower limb kinematics and kinetics during step-up and step-down tasks in individuals with progressive collapsing foot deformity","authors":"Ahmed Dami , Eléna Payen Schalkens , Tahereh Ghabdian , Nader Farahpour , Pier-Luc Isabelle , Gabriel Moisan","doi":"10.1016/j.jbiomech.2025.113136","DOIUrl":"10.1016/j.jbiomech.2025.113136","url":null,"abstract":"<div><div>Progressive collapsing foot deformity (PCFD) is a debilitating condition causing significant biomechanical impairments. Custom-made foot orthoses (FOs) provide a non-invasive treatment by supporting the medial longitudinal arch and improving foot and ankle biomechanics. While previous studies on PCFD have predominantly investigated the biomechanical effects of FOs during walking, their impact on more demanding dynamic tasks remains unclear. This study aimed to investigate the effects of custom-made FOs on lower limb kinematics and kinetics during step-up (SU), step-down (SD), and step-down on a medially inclined surface (SDI) in individuals with PCFD. Twenty participants with flexible PCFD performed SU, SD and SDI tasks with and without FOs. Hip, knee, ankle and midfoot angles and moments were calculated and compared across conditions using one-dimensional statistical parametric mapping. Custom-made FOs reduced midfoot dorsiflexion across all tasks (SU: 4.9°; SD: 4.6°; SDI: 5.4°) and decreased ankle eversion during SU (2.9°) and SD (3.5°), but the reduction during SDI was non-significant. Custom FOs also reduced ankle inversion moments while increasing knee abduction moments during all step tasks. These findings indicate that custom-made FOs effectively support the medial longitudinal arch and limit foot pronation during dynamic movements, likely reducing loading on the medial ankle structures. However, their biomechanical efficacy was less pronounced when individuals with PCFD landed on a medially inclined surface. These findings highlight FOs potential as a conservative intervention for flexible PCFD to improve lower limb biomechanics.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113136"},"PeriodicalIF":2.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145781392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Shoulder joint movement during reaching to the contralateral and ipsilateral lumbar back 肩关节在到达对侧和同侧腰背部时的运动

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-15 DOI: 10.1016/j.jbiomech.2025.113131

Takanao Shirai , Tomohito Ijiri , Toshiaki Suzuki

In activities of daily living, hand-behind-back (HBB) motion often requires reaching not only to the spinal column but also to the contralateral or ipsilateral lumbar back. However, the specific shoulder joint kinematics involved in HBB motion toward these directions remain unclear. This study aimed to understand the shoulder joint motions that occur during HBB motion when reaching the contralateral or ipsilateral side. The participants were 18 healthy men (age, 29.8 ± 6.8 years). The measurement task comprised three types of HBB motions: placing the thumb at the first lumbar vertebra and placing the thumb on the contralateral and ipsilateral lumbar back. Shoulder joint extension, abduction, internal rotation angles were investigated using a three-dimensional motion analyzer. For the reaching to the contralateral lumbar back in this study, shoulder abduction was 17.7° ± 7.1° and shoulder extension was 28.8° ± 6.6°, internal rotation was 34.8° ± 10.5°; to reach the ipsilateral lumbar back, shoulder abduction was 43.0° ± 8.9° and shoulder extension was 37.3° ± 6.1°, internal rotation was 30.4° ± 9.0°. The contralateral reach showed greater internal rotation of the shoulder joint and lesser shoulder joint extension and abduction than the ipsilateral reach. The contralateral reach showed a significant negative correlation with shoulder joint internal rotation and extension. In the HBB motion, the shoulder joint movements differ when reaching the contralateral and ipsilateral lumbar back. As the HBB motion may involve reaching the contralateral or ipsilateral side, the movements of the shoulder joint should be evaluated in relation to daily activities.

在日常生活活动中，手背（HBB）运动通常不仅需要到达脊柱，还需要到达对侧或同侧腰背。然而，HBB向这些方向运动的具体肩关节运动学仍不清楚。本研究旨在了解当到达对侧或同侧时，HBB运动中发生的肩关节运动。健康男性18例（年龄29.8±6.8岁）。测量任务包括三种类型的HBB运动：将拇指放在第一腰椎和将拇指放在对侧和同侧腰背。采用三维运动分析仪研究肩关节的伸展、外展、内旋角度。本研究中到达对侧腰背部时，肩关节外展为17.7°±7.1°，肩关节外展为28.8°±6.6°，内旋为34.8°±10.5°；肩关节外展为43.0°±8.9°，肩关节外展为37.3°±6.1°，内旋为30.4°±9.0°，达到同侧腰背部。与同侧臂相比，对侧臂表现出更大的肩关节内旋和更小的肩关节伸展和外展。对侧伸度与肩关节内旋、内伸呈显著负相关。在HBB运动中，肩关节运动在到达对侧和同侧腰背部时是不同的。由于HBB运动可能涉及到对侧或同侧，因此应根据日常活动评估肩关节的运动。

{"title":"Shoulder joint movement during reaching to the contralateral and ipsilateral lumbar back","authors":"Takanao Shirai , Tomohito Ijiri , Toshiaki Suzuki","doi":"10.1016/j.jbiomech.2025.113131","DOIUrl":"10.1016/j.jbiomech.2025.113131","url":null,"abstract":"<div><div>In activities of daily living, hand-behind-back (HBB) motion often requires reaching not only to the spinal column but also to the contralateral or ipsilateral lumbar back. However, the specific shoulder joint kinematics involved in HBB motion toward these directions remain unclear. This study aimed to understand the shoulder joint motions that occur during HBB motion when reaching the contralateral or ipsilateral side. The participants were 18 healthy men (age, 29.8 ± 6.8 years). The measurement task comprised three types of HBB motions: placing the thumb at the first lumbar vertebra and placing the thumb on the contralateral and ipsilateral lumbar back. Shoulder joint extension, abduction, internal rotation angles were investigated using a three-dimensional motion analyzer. For the reaching to the contralateral lumbar back in this study, shoulder abduction was 17.7° ± 7.1° and shoulder extension was 28.8° ± 6.6°, internal rotation was 34.8° ± 10.5°; to reach the ipsilateral lumbar back, shoulder abduction was 43.0° ± 8.9° and shoulder extension was 37.3° ± 6.1°, internal rotation was 30.4° ± 9.0°. The contralateral reach showed greater internal rotation of the shoulder joint and lesser shoulder joint extension and abduction than the ipsilateral reach. The contralateral reach showed a significant negative correlation with shoulder joint internal rotation and extension. In the HBB motion, the shoulder joint movements differ when reaching the contralateral and ipsilateral lumbar back. As the HBB motion may involve reaching the contralateral or ipsilateral side, the movements of the shoulder joint should be evaluated in relation to daily activities.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113131"},"PeriodicalIF":2.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Markerless motion capture for running: validity and reliability of whole-body, joint, and muscle kinematics 用于跑步的无标记动作捕捉：全身、关节和肌肉运动学的有效性和可靠性

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-15 DOI: 10.1016/j.jbiomech.2025.113133

Jasper Verheul, Owain Hughes, Luke Hitchens, Toby Atherton, Toby Sauter, Amir Radwan, Elis Pryce, Alice Mitchell, Sophie Burton

Markerless motion capture can greatly enhance the accessibility and efficiency of running-kinematics analysis. In this study we aimed to establish the validity and reliability of a markerless motion-capture system (OpenCap) for measuring kinematics of the whole body, individual joints, and lower-limb muscle–tendon units, during running at various speeds. Markerless and marker-based motion-capture results were compared for 30 runners running on a treadmill at five speeds (8–16 km/hr). OpenCap demonstrated similar validity for joint angle measurements compared to other markerless systems that have previously been compared to marker-based motion capture. However, we found systematic differences between OpenCap and marker-based motion capture throughout the stride cycle, and across running speeds and kinematic variables. Between-system disagreements were most evident around peak centre-of-mass displacements and joint angles, and during the swing phase, with smaller differences observed at touchdown, take-off, and during the stance phase. We thus recommend caution when quantitatively comparing kinematic outcomes from OpenCap to other motion-capture systems. Despite these differences, high agreement in inter-stride and inter-trial variability was observed between systems across all kinematic variables. Overall, OpenCap is a powerful tool to enable accessible, efficient, and reliable 3D measurements of whole-body, joint, and muscle–tendon unit kinematics during running.

无标记运动捕捉可以大大提高运动分析的可及性和效率。在这项研究中，我们旨在建立一个无标记运动捕捉系统（OpenCap）的有效性和可靠性，用于测量在不同速度下跑步时全身、单个关节和下肢肌肉肌腱单元的运动学。研究人员比较了30名跑步者在跑步机上以5种速度（8-16公里/小时）跑步的无标记和基于标记的动作捕捉结果。与其他无标记系统相比，OpenCap在关节角度测量方面表现出类似的有效性，这些系统之前已经与基于标记的动作捕捉进行了比较。然而，我们发现OpenCap和基于标记的运动捕捉在整个跨步周期、跑步速度和运动学变量之间存在系统性差异。系统之间的差异在峰值质心位移和关节角度以及摆动阶段最为明显，在着陆、起飞和站立阶段的差异较小。因此，我们建议在定量比较OpenCap与其他动作捕捉系统的运动学结果时要谨慎。尽管存在这些差异，但在所有运动学变量的系统之间观察到跨步幅和跨试验变异性的高度一致性。总的来说，OpenCap是一个强大的工具，可以在跑步过程中对全身、关节和肌肉肌腱单元进行方便、高效和可靠的3D测量。

{"title":"Markerless motion capture for running: validity and reliability of whole-body, joint, and muscle kinematics","authors":"Jasper Verheul, Owain Hughes, Luke Hitchens, Toby Atherton, Toby Sauter, Amir Radwan, Elis Pryce, Alice Mitchell, Sophie Burton","doi":"10.1016/j.jbiomech.2025.113133","DOIUrl":"10.1016/j.jbiomech.2025.113133","url":null,"abstract":"<div><div>Markerless motion capture can greatly enhance the accessibility and efficiency of running-kinematics analysis. In this study we aimed to establish the validity and reliability of a markerless motion-capture system (OpenCap) for measuring kinematics of the whole body, individual joints, and lower-limb muscle–tendon units, during running at various speeds. Markerless and marker-based motion-capture results were compared for 30 runners running on a treadmill at five speeds (8–16 km/hr). OpenCap demonstrated similar validity for joint angle measurements compared to other markerless systems that have previously been compared to marker-based motion capture. However, we found systematic differences between OpenCap and marker-based motion capture throughout the stride cycle, and across running speeds and kinematic variables. Between-system disagreements were most evident around peak centre-of-mass displacements and joint angles, and during the swing phase, with smaller differences observed at touchdown, take-off, and during the stance phase. We thus recommend caution when quantitatively comparing kinematic outcomes from OpenCap to other motion-capture systems. Despite these differences, high agreement in inter-stride and inter-trial variability was observed between systems across all kinematic variables. Overall, OpenCap is a powerful tool to enable accessible, efficient, and reliable 3D measurements of whole-body, joint, and muscle–tendon unit kinematics during running.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113133"},"PeriodicalIF":2.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Novel volumetric strain energy function modeling of the dependence of aortic compressibility on smooth muscle state 主动脉压缩性随平滑肌状态变化的新型体积应变能函数模型

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-13 DOI: 10.1016/j.jbiomech.2025.113124

Yuxin Zhang , Yiwen Wang , Lijie Zhou , Xuefeng Wu

The active mechanical behavior of the vascular system is critical to circulatory homeostasis as a hemodynamic adaptive regulatory mechanism. Current mainstream vascular mechanics models focus on investigating the mechanical contribution of collagen and elastic fibers while ignoring the key variable of smooth muscle status. This limits their realism and clinical predictive power in simulating physiopathological remodeling of the vasculature. To quantify the effect of smooth muscle state on aortic wall compressibility and to characterize its regulatory ability, a novel state-dependent volumetric strain energy function model was proposed; based on the classical pressure-volume response experiments, the tissue compressibility behaviors under different smooth muscle activation states were quantitatively characterized, and it was confirmed that tissue compressibility was negatively correlated with smooth muscle activation state (compressibility was higher in the non-responsive samples); a two-parameter co-calibration scheme was adopted to simultaneously identify the state-dependent bulk modulus (

K_{x}

) and compressibility factor (

α

), and successfully established the three types of smooth muscle activation states: relaxation (

K_{r}

=6.46 MPa,

α_{r}

=12.73), normal tension (

K_{n}

=6.95 MPa,

α_{n}

=20.25), and contraction (

K_{c}

=9.83 MPa,

α_{c}

=42.07). The closed-loop validation of the experiment and the model shows that the model achieves effective distinction of the compressibility response of the smooth muscle state, which provides a multi-state modeling strategy for vascular biomechanical modeling and has important theoretical value and clinical significance for the study of the vascular disease mechanism and the optimization of endovascular treatment devices.

作为一种血液动力学适应性调节机制，血管系统的主动机械行为对循环稳态至关重要。目前主流血管力学模型关注的是胶原和弹性纤维的力学贡献，而忽略了平滑肌状态这一关键变量。这限制了它们在模拟脉管系统的生理病理重塑方面的真实性和临床预测能力。为了量化平滑肌状态对主动脉壁压缩性的影响并表征其调节能力，提出了一种新的基于状态的体积应变能函数模型；基于经典压力-体积响应实验，定量表征了不同平滑肌激活状态下的组织可压缩性行为，证实了组织可压缩性与平滑肌激活状态呈负相关（无响应样品的可压缩性更高）；采用双参数协标定方案，同时确定了与状态相关的体积模量（Kx）和压缩系数（α），成功建立了3种平滑肌激活状态：松弛（Kr=6.46 MPa, αr=12.73）、法向张力（Kn=6.95 MPa, αn=20.25）和收缩（Kc=9.83 MPa, αc=42.07）。实验与模型的闭环验证表明，该模型实现了平滑肌状态可压缩性反应的有效区分，为血管生物力学建模提供了一种多状态建模策略，对研究血管疾病机制和优化血管内治疗装置具有重要的理论价值和临床意义。

{"title":"Novel volumetric strain energy function modeling of the dependence of aortic compressibility on smooth muscle state","authors":"Yuxin Zhang , Yiwen Wang , Lijie Zhou , Xuefeng Wu","doi":"10.1016/j.jbiomech.2025.113124","DOIUrl":"10.1016/j.jbiomech.2025.113124","url":null,"abstract":"<div><div>The active mechanical behavior of the vascular system is critical to circulatory homeostasis as a hemodynamic adaptive regulatory mechanism. Current mainstream vascular mechanics models focus on investigating the mechanical contribution of collagen and elastic fibers while ignoring the key variable of smooth muscle status. This limits their realism and clinical predictive power in simulating physiopathological remodeling of the vasculature. To quantify the effect of smooth muscle state on aortic wall compressibility and to characterize its regulatory ability, a novel state-dependent volumetric strain energy function model was proposed; based on the classical pressure-volume response experiments, the tissue compressibility behaviors under different smooth muscle activation states were quantitatively characterized, and it was confirmed that tissue compressibility was negatively correlated with smooth muscle activation state (compressibility was higher in the non-responsive samples); a two-parameter co-calibration scheme was adopted to simultaneously identify the state-dependent bulk modulus (<span><math><msub><mi>K</mi><mi>x</mi></msub></math></span>) and compressibility factor (<span><math><mi>α</mi></math></span>), and successfully established the three types of smooth muscle activation states: relaxation (<span><math><msub><mi>K</mi><mi>r</mi></msub></math></span>=6.46 MPa, <span><math><msub><mi>α</mi><mi>r</mi></msub></math></span>=12.73), normal tension (<span><math><msub><mi>K</mi><mi>n</mi></msub></math></span>=6.95 MPa, <span><math><msub><mi>α</mi><mi>n</mi></msub></math></span>=20.25), and contraction (<span><math><msub><mi>K</mi><mi>c</mi></msub></math></span>=9.83 MPa, <span><math><msub><mi>α</mi><mi>c</mi></msub></math></span>=42.07). The closed-loop validation of the experiment and the model shows that the model achieves effective distinction of the compressibility response of the smooth muscle state, which provides a multi-state modeling strategy for vascular biomechanical modeling and has important theoretical value and clinical significance for the study of the vascular disease mechanism and the optimization of endovascular treatment devices.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113124"},"PeriodicalIF":2.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Peak lower limb joint angles are weak predictors of hamstring length change during sprinting 峰值下肢关节角度是短跑中腘绳肌长度变化的弱预测因子

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-13 DOI: 10.1016/j.jbiomech.2025.113127

Shayne Vial , Jodie Cochrane Wilkie , Anthony J. Blazevich , Daniel Kadlec

Non-contact hamstring injuries (HSIs) commonly occur during the late swing phase of sprinting, when muscle–tendon units (MTUs) approach maximum length. Although sagittal-plane pelvis, hip and knee angles are often used as surrogate measures of overall hamstring lengthening, their predictive validity remains uncertain. This study investigated whether peak three-dimensional lower limb joint angles predict length change in the biarticular hamstring MTUs from peak hip flexion through to toe off (0–100 %) in fourteen intermediate-level male soccer players sprinting at maximal speed (8.56 ± 0.47 m·s⁻¹). Participant-specific musculoskeletal models were used to compute MTU lengths for the biceps femoris long head (BFlh), semimembranosus (SM), and semitendinosus (ST). To account for inter-subject temporal variability and enable accurate point-to-point comparisons across trials, dynamic time warping was applied for non-linear temporal registration. Statistical parametric mapping regression was used to assess associations between pelvis, hip and knee peak joint angles (sagittal, frontal, transverse) and length change of BFlh, SM, and ST. Peak sagittal angles were poor predictors while peak frontal pelvis angle was negatively associated with MTU length change during late swing (BFlh peak |r| = −0.371; SM peak |r| = −0.460). Frontal hip adduction was negatively associated with MTU length change from peak hip flexion to early stance (peak |r| −0.39 to −0.46). Internal hip rotation was associated with SM and ST lengthening (peak |r| = 0.51) from late swing to early stance. Knee extension angles showed no significant associations. These findings suggest caution when using single-plane joint angles as isolated indicators of hamstring MTU length.

非接触性腿筋损伤（hsi）通常发生在冲刺的后期摇摆阶段，此时肌肉-肌腱单位（mtu）接近最大长度。尽管骨盆、髋关节和膝关节矢状面角度常被用作整体腘绳肌延长的替代测量，但其预测有效性仍不确定。本研究调查了14名以最大速度（8.56±0.47 m·s−1）冲刺的中等水平男性足球运动员，其双关节腿筋MTUs从髋屈峰到脚趾脱落（0 - 100%）的峰值三维下肢关节角是否能预测长度变化。参与者特定的肌肉骨骼模型被用来计算股骨二头肌长头（BFlh）、半膜肌（SM）和半腱肌（ST）的MTU长度。为了解释受试者间的时间变异性，并在试验中实现准确的点对点比较，动态时间扭曲应用于非线性时间配准。使用统计参数映射回归来评估骨盆、髋关节和膝关节峰值关节角度（矢状面、正位、横位）与BFlh、SM和st长度变化之间的关系。矢状面峰值角度是较差的预测指标，而骨盆正面峰值角度与挥杆后期MTU长度变化呈负相关（BFlh峰值|r| = - 0.371； SM峰值|r| = - 0.460）。髋额部内收与髋屈曲峰至早期站姿的MTU长度变化呈负相关（峰值|或| - 0.39至- 0.46）。从摇摆晚期到站立早期，髋关节内旋与SM和ST延长相关（峰值|r| = 0.51）。膝关节伸展角度无显著相关性。这些结果提示在使用单平面关节角度作为腘绳肌MTU长度的单独指标时要谨慎。

{"title":"Peak lower limb joint angles are weak predictors of hamstring length change during sprinting","authors":"Shayne Vial , Jodie Cochrane Wilkie , Anthony J. Blazevich , Daniel Kadlec","doi":"10.1016/j.jbiomech.2025.113127","DOIUrl":"10.1016/j.jbiomech.2025.113127","url":null,"abstract":"<div><div>Non-contact hamstring injuries (HSIs) commonly occur during the late swing phase of sprinting, when muscle–tendon units (MTUs) approach maximum length. Although sagittal-plane pelvis, hip and knee angles are often used as surrogate measures of overall hamstring lengthening, their predictive validity remains uncertain. This study investigated whether peak three-dimensional lower limb joint angles predict length change in the biarticular hamstring MTUs from peak hip flexion through to toe off (0–100 %) in fourteen intermediate-level male soccer players sprinting at maximal speed (8.56 ± 0.47 m·s<sup>−1</sup>). Participant-specific musculoskeletal models were used to compute MTU lengths for the biceps femoris long head (BFlh), semimembranosus (SM), and semitendinosus (ST). To account for inter-subject temporal variability and enable accurate point-to-point comparisons across trials, dynamic time warping was applied for non-linear temporal registration. Statistical parametric mapping regression was used to assess associations between pelvis, hip and knee peak joint angles (sagittal, frontal, transverse) and length change of BFlh, SM, and ST. Peak sagittal angles were poor predictors while peak frontal pelvis angle was negatively associated with MTU length change during late swing (BFlh peak |r| = −0.371; SM peak |r| = −0.460). Frontal hip adduction was negatively associated with MTU length change from peak hip flexion to early stance (peak |r| −0.39 to −0.46). Internal hip rotation was associated with SM and ST lengthening (peak |r| = 0.51) from late swing to early stance. Knee extension angles showed no significant associations. These findings suggest caution when using single-plane joint angles as isolated indicators of hamstring MTU length.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"196 ","pages":"Article 113127"},"PeriodicalIF":2.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Lumbar spine passive stiffness correlates to peak lumbar spine angle following postural perturbations 腰椎被动僵硬度与姿势扰动后腰椎角峰值相关

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-12-13 DOI: 10.1016/j.jbiomech.2025.113129

Joshua S.M. Lowery , Emma J. Conway , Kayla M. Fewster

The passive tissues of the lumbar spine have been hypothesized to be a contributing factor to the stability of the spinal column, and although this has been primarily studied under non-perturbation conditions, it has been hypothesized that passive structures may play an important role during unexpected perturbations, during which they have no neural time delay in their counter-moment production. However, it remains unknown if those with higher lumbar spine passive stiffness (LSPS) have different responses during dynamic perturbations. Therefore, the purpose of the current work was to determine if one’s LSPS correlates to the maximum amount of lumbar flexion and centre of pressure excursion following an unexpected perturbation. Twenty participants completed a blinded box-drop task. Their lumbar spine angle and centre of pressure were measured, and peak lumbar spine angle and centre of pressure excursion were determined. A significant relationship was observed between the peak lumbar spine flexion angle experienced following an unexpected perturbation and the stiffness in the low (p = 0.025, R² = 0.249) and transition (p = 0.001, R² = 0.500) stiffness zones in extension. Individuals with higher LSPS experienced lower peak lumbar spine angles. No relationship was observed between LSPS and centre of pressure excursion. Results suggest that LSPS may be a stabilizing component of the lumbar spine following unexpected perturbations. However, the lack of an observable relationship between LSPS and centre of pressure excursion may suggest that LSPS is less indicative of overall postural stability following a perturbation.

腰椎的被动组织被假设为脊柱稳定性的一个促进因素，尽管这主要是在非扰动条件下进行的研究，但已经假设被动结构可能在意外扰动中发挥重要作用，在此期间，它们在反矩产生中没有神经时间延迟。然而，对于那些腰椎被动刚度（LSPS）较高的患者在动态扰动下是否有不同的反应，目前尚不清楚。因此，当前工作的目的是确定一个人的LSPS是否与意外扰动后腰椎屈曲和压力中心偏移的最大量相关。20名参与者完成了一个盲放箱子的任务。测量腰椎角和压力中心，确定腰椎角峰值和压力偏移中心。意外扰动后腰椎屈曲角峰值与低度区（p = 0.025, R2 = 0.249）和过渡区（p = 0.001, R2 = 0.500）伸直刚度之间存在显著关系。LSPS较高的个体腰椎角峰值较低。没有观察到LSPS和压力中心偏移之间的关系。结果表明，LSPS可能是腰椎意外扰动后的稳定成分。然而，缺乏可观察到的LSPS和压力中心偏移之间的关系可能表明LSPS在扰动后不太能表明整体姿势稳定性。

{"title":"Lumbar spine passive stiffness correlates to peak lumbar spine angle following postural perturbations","authors":"Joshua S.M. Lowery , Emma J. Conway , Kayla M. Fewster","doi":"10.1016/j.jbiomech.2025.113129","DOIUrl":"10.1016/j.jbiomech.2025.113129","url":null,"abstract":"<div><div>The passive tissues of the lumbar spine have been hypothesized to be a contributing factor to the stability of the spinal column, and although this has been primarily studied under non-perturbation conditions, it has been hypothesized that passive structures may play an important role during unexpected perturbations, during which they have no neural time delay in their counter-moment production. However, it remains unknown if those with higher lumbar spine passive stiffness (LSPS) have different responses during dynamic perturbations. Therefore, the purpose of the current work was to determine if one’s LSPS correlates to the maximum amount of lumbar flexion and centre of pressure excursion following an unexpected perturbation. Twenty participants completed a blinded box-drop task. Their lumbar spine angle and centre of pressure were measured, and peak lumbar spine angle and centre of pressure excursion were determined. A significant relationship was observed between the peak lumbar spine flexion angle experienced following an unexpected perturbation and the stiffness in the low (p = 0.025, R<sup>2</sup> = 0.249) and transition (p = 0.001, R<sup>2</sup> = 0.500) stiffness zones in extension. Individuals with higher LSPS experienced lower peak lumbar spine angles. No relationship was observed between LSPS and centre of pressure excursion. Results suggest that LSPS may be a stabilizing component of the lumbar spine following unexpected perturbations. However, the lack of an observable relationship between LSPS and centre of pressure excursion may suggest that LSPS is less indicative of overall postural stability following a perturbation.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113129"},"PeriodicalIF":2.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0