Journal of biomechanics最新文献_第8页

Effects of an elastic hip exoskeleton on stability quantified by mechanical energetics and whole-body angular momentum during walking with treadmill belt speed perturbations 在跑步机带速度扰动下，弹性髋外骨骼对机械能量学和全身角动量量化的稳定性的影响

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-27 DOI: 10.1016/j.jbiomech.2025.112784

Pawel R. Golyski , Nicholas K. Swaich , Fausto A. Panizzolo , Gregory S. Sawicki

{"title":"Effects of an elastic hip exoskeleton on stability quantified by mechanical energetics and whole-body angular momentum during walking with treadmill belt speed perturbations","authors":"Pawel R. Golyski , Nicholas K. Swaich , Fausto A. Panizzolo , Gregory S. Sawicki","doi":"10.1016/j.jbiomech.2025.112784","DOIUrl":"10.1016/j.jbiomech.2025.112784","url":null,"abstract":"<div><div>Relative to motorized devices, passive hip exoskeletons with elastic actuation provide cheaper and lower-profile solutions to assist locomotion during walking. However, the influence of elastic hip assistance on stability during walking is poorly understood. Here, we investigated the effects on stability of a hip exoskeleton that provided elastic flexion torque during late stance. We quantified stability using both sagittal whole-body angular momentum (WBAM) range and whole-body mechanical work during walking with unexpected anteroposterior treadmill belt accelerations among 11 healthy uninjured individuals. We hypothesized that during perturbations, 1) an elastic hip exoskeleton would improve stability as measured by a smaller range in sagittal WBAM and a lower whole-body energetic demand imposed by the perturbation, and 2) this improvement in whole-body energetic demand would be mediated by the exoskeleton shifting the local mechanical energetics of the hip joint to oppose the energetic demands of the perturbation. Contrary to our hypotheses, the elastic hip exoskeleton did not influence whole-body work demands imposed by perturbations (p>0.226). Additionally, while sagittal WBAM ranges were larger during unperturbed walking with increasing exoskeleton stiffness due to alterations in trunk kinematics (p<0.001), this effect did not extend to perturbed walking (p>0.419). Further, while higher exoskeleton stiffnesses (0.66–1.0 Nm/deg) shifted ipsilateral hip joint work in opposition to whole-body work demands, the same stiffnesses shifted contralateral hip joint work toward whole-body work demands. Our findings demonstrate conclusions drawn about stability from sagittal WBAM range do not carry over from unperturbed to perturbed walking.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112784"},"PeriodicalIF":2.4,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144184418","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

Residual strains and morphometry in the human esophagus: Dependence on location, age, and gender 人类食道的残余应变和形态测定：与位置、年龄和性别的关系

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-27 DOI: 10.1016/j.jbiomech.2025.112793

Dimitrios P. Sokolis , Stavroula A. Papadodima , Christos Manopoulos

{"title":"Residual strains and morphometry in the human esophagus: Dependence on location, age, and gender","authors":"Dimitrios P. Sokolis , Stavroula A. Papadodima , Christos Manopoulos","doi":"10.1016/j.jbiomech.2025.112793","DOIUrl":"10.1016/j.jbiomech.2025.112793","url":null,"abstract":"<div><h3>Abstract</h3><div>The esophagus is a multi-layered organ that transports food to the stomach. While extensive biomechanical data exist for animal esophagi, human data remain limited. To address this, we analyzed residual deformations and zero-stress configurations in esophageal tissue from twenty-one cadavers (aged 21-84). Rings were photographed from fifteen equidistant locations before and after radial cutting and dissection into mucosa-submucosa and muscle layers. Image analysis revealed that the opening angles of the intact wall and muscle—slightly greater for the latter—did not vary significantly along the esophagus (<em>p</em> > 0.05 across age groups and genders). Conversely, the mucosa-submucosa had a larger opening angle, increasing along the esophagus (<em>p</em> < 0.05 in young subjects and both genders). Residual strains released by radial cutting and layer separation showed no anatomical position dependence (<em>p</em> > 0.05). The no-load internal circumference remained age-independent (<em>p</em> > 0.05 at all locations), while intact-wall thickness increased from young to middle-aged subjects due to mucosa-submucosa expansion (<em>p</em> < 0.05 in the upper half). No significant muscle growth occurred with age. This correlated with a rise in intact-wall opening angle between those age groups (<em>p</em> < 0.05 at the same sites), driven by more compressive internal residual strain (<em>p</em> < 0.05 near mid-esophagus). Age-related variations in layer-specific opening angles and residual strains were minimal (<em>p</em> > 0.05 in most locations). Males had wider, thicker esophagi (<em>p</em> < 0.05 in the upper half), but gender had no significant effect on opening angles and residual strains. This database provides new insights into the residual strains of the human esophagus and enhances computational simulations of transport and clinical interventions.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"189 ","pages":"Article 112793"},"PeriodicalIF":2.4,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470149","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

Biomechanical analysis of gait termination within set stopping distance: A pilot study 设定停止距离内步态终止的生物力学分析：一项初步研究

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-26 DOI: 10.1016/j.jbiomech.2025.112782

Minoru Kimoto , Kyoji Okada , Kazutaka Mitobe , Masachika Saito , Hitoshi Sakamoto

{"title":"Biomechanical analysis of gait termination within set stopping distance: A pilot study","authors":"Minoru Kimoto , Kyoji Okada , Kazutaka Mitobe , Masachika Saito , Hitoshi Sakamoto","doi":"10.1016/j.jbiomech.2025.112782","DOIUrl":"10.1016/j.jbiomech.2025.112782","url":null,"abstract":"<div><div>Under conditions of restricted stopping distances, gait termination comprises a critical motor task, wherein precise balance control and coordination are prerequisites to prevent falls or collisions. Despite several studies on gait termination, the specific biomechanical effects during unplanned gait termination remain underexplored. To provide insights into adaptive motor-control strategies under challenging conditions, such as abrupt stopping, we ascertained trends in biomechanical adaptations during gait termination within restricted distances in healthy young adults. This cross-sectional study included 12 healthy young adults. Participants were instructed to follow a guiding line to control walking speed (at 100 % and 125 % of comfortable speed) and stopped in front of an emerging red line at 1.75 × or 1.5 × the leg length (measured from the anterior superior iliac spine to the medial malleolus) from the pelvis marker. Three-dimensional motion analysis and force-plate data were used to evaluate key biomechanical parameters. Two-way repeated-measures analysis of variance, with velocity and distance as variables, was performed for each parameter. Among participants [age, mean (SD): 22.4 (3.1) years], short, compared to long, stopping distances generated smaller anteroposterior (AP) maximum forces (propulsion; <em>P</em> < 0.001) and reduced the event time at the first stepping from the emerging red line (<em>P</em> = 0.02) as well as the AP minimum force (braking; <em>P</em> < 0.001) and time interval (<em>P</em> = 0.02) between toe-off and first stepping. Thus, biomechanical strategies employed by healthy young adults in adaptation to restricted stopping distances facilitate a better understanding of motor control and balance under constrained gait conditions.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112782"},"PeriodicalIF":2.4,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144184420","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

Stability vs. performance: The role of weight shift during gait initiation for people with Parkinson disease 稳定性与表现：体重变化在帕金森病患者步态启动中的作用

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-26 DOI: 10.1016/j.jbiomech.2025.112783

Chelsea Parker Duppen , Nikhil Sachdeva , Hailey Wrona , Nina Browner , Michael D Lewek

{"title":"Stability vs. performance: The role of weight shift during gait initiation for people with Parkinson disease","authors":"Chelsea Parker Duppen , Nikhil Sachdeva , Hailey Wrona , Nina Browner , Michael D Lewek","doi":"10.1016/j.jbiomech.2025.112783","DOIUrl":"10.1016/j.jbiomech.2025.112783","url":null,"abstract":"<div><div>People with Parkinson disease (PwPD) demonstrate hypokinesia during gait initiation, marked by a decreased first step length and reduced anticipatory postural adjustment (APA) size. Effective postural control is critical for shifting from double to single limb support during gait initiation. Although PwPD are known to have impaired postural control strategies, its impact on spatial aspects of gait initiation remains unclear. This study investigated how different weight shift amplitudes onto the initial stance limb during gait initiation affect first step length, mediolateral APA size, and the ability to bring the centre of mass (COM) close to the centre of pressure (COP) for PwPD. We hypothesized that cueing for larger weight shifts would yield a larger APA, reduce the distance between COP and COM in the mediolateral direction (COM-COMx), and result in larger first steps. Eleven adults with idiopathic PD (Hoehn & Yahr Stages 1–3) were given visual biofeedback to cue weight shifts of 40, 60, and 80 % towards the initial stance limb before initiating gait. No significant difference was found between uncued and cued conditions for first step length (p = 0.210), however, cued conditions resulted in smaller mediolateral APA sizes (p < 0.001), and reduced COP-COMx compared to uncued trials (p < 0.001). A weak positive correlation was found between mediolateral APA size and first step length (ρ = 0.236, p = 0.005), suggesting a very small role of APAs in first step length amplitude in this population. In conclusion, cueing for increased weight shift amplitude improves stability but does not enhance first step length during gait initiation for PwPD.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112783"},"PeriodicalIF":2.4,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169241","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

Computational modeling of biomechanical response of osteocyte integrin and cytoskeleton based on the piezoelectricity of bone matrix 基于骨基质压电性的骨细胞整合素和细胞骨架生物力学响应计算模型

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-24 DOI: 10.1016/j.jbiomech.2025.112778

Zhengbiao Yang , Yuqing Duanwang , Aohua Zhang , Shibo Gu , Yutang Xie , Le Zhao , Yanru Xue , Yanqin Wang , Xiaogang Wu , Meng Zhang , Weiyi Chen

{"title":"Computational modeling of biomechanical response of osteocyte integrin and cytoskeleton based on the piezoelectricity of bone matrix","authors":"Zhengbiao Yang , Yuqing Duanwang , Aohua Zhang , Shibo Gu , Yutang Xie , Le Zhao , Yanru Xue , Yanqin Wang , Xiaogang Wu , Meng Zhang , Weiyi Chen","doi":"10.1016/j.jbiomech.2025.112778","DOIUrl":"10.1016/j.jbiomech.2025.112778","url":null,"abstract":"<div><div>Osteocytes are key in bone remodeling, responding to mechanical stimuli. The piezoelectric bone matrix converts these stimuli into electrical signals, influencing remodeling. To delve deeper into this, we created an osteocyte model within a piezoelectric bone matrix, incorporating the lacuna-canalicular system and mechanosensors such as integrins, cytoskeleton, and primary cilia. Upon subjecting the bone matrix to triaxial dynamic displacement loads, we examined the electric potential and flow velocity distributions and analyzed the mechanical signals of six mechanosensors. The results show that the strain is greater when the bone matrix is piezoelectric than non-piezoelectric. The maximum average potential of the surface structure of the cell membrane is about 69.3 mV. Piezoelectricity significantly increases the fluid velocity and changes the trend. The cytoskeleton and integrins in cell process experience greater stress than in cell body. Microtubules experience greater stress than actin filaments. Among all integrins, those in contact with collagen hillocks experience the greatest stress. In individual integrin, the β subunit has higher stress than α subunit, and the stress of legs connected to cytoskeleton is higher than head contacted with fluid. Within the cytoplasm, the stress of integrin increases with a decrease of the surrounding cytoskeleton density. Moreover, collagen hillocks have the greatest fluid shear stress and stress. Integrins, primary cilia, and cytoskeleton all exhibit significant displacement signal amplification, especially integrins. In conclusion, this study illuminates the complex process of mechanosensing in osteocytes within a piezoelectric environment. The established model offers valuable insights into the mechanism of osteomechanical signal transduction.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112778"},"PeriodicalIF":2.4,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169242","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

Contribution of whole-body momentum regulation towards jump height differences in two-foot running jumps with and without a basketball 全身动量调节对带和不带篮球两尺跑跳跳跃高度差异的贡献

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-23 DOI: 10.1016/j.jbiomech.2025.112781

Jun Ming Liu, Antonia Zaferiou

{"title":"Contribution of whole-body momentum regulation towards jump height differences in two-foot running jumps with and without a basketball","authors":"Jun Ming Liu, Antonia Zaferiou","doi":"10.1016/j.jbiomech.2025.112781","DOIUrl":"10.1016/j.jbiomech.2025.112781","url":null,"abstract":"<div><div>Two-foot running jumps (TFRJs) are frequently performed by basketball players with or without a basketball, but the effects of ball control on jump performance and whole-body momentum regulation are unknown. We examined the differences between TFRJ with and without a ball in initial and takeoff center of mass (COM) vertical velocities and net upward impulse. Fifteen male and six female recreational to college-level basketball players performed TFRJs with and without ball towards an adjustable hoop. Jump height was computed as vertical jump displacement from takeoff COM upward velocity. Linear mixed models were used to compare jump height and contributing variables across conditions. Group results revealed lower jump heights, lower net upward impulses, and lower second leg upward impulses (each comparison p < 0.001) during TFRJs with versus without a ball. Within-participant results revealed a mixture of contributing factors to lower jump heights across participants, and three did not exhibit significant differences in jump heights across jumping conditions. Compared to TFRJs without ball, eighteen participants had lower jump heights during TFRJ with a ball, fourteen participants generated less net upward impulse due to less first leg or second leg upward impulse generation, or an increase in the downward impulse due to bodyweight (via increased ground contact duration and/or lower average upward ground reaction forces), and five participants had faster initial downward COM velocity due to differences in the running approach during TFRJ with a ball. These participant-specific contributions to jump height during differing TFRJ tasks provide meaningful motor control contexts to inform coaching.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112781"},"PeriodicalIF":2.4,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169240","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

Role of muscle forces on strain distributions in the proximal femur 肌力对股骨近端应变分布的作用

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-23 DOI: 10.1016/j.jbiomech.2025.112743

Michael P. Rogalski , Saulo Martelli , Marcus G. Pandy , Mariana E. Kersh

{"title":"Role of muscle forces on strain distributions in the proximal femur","authors":"Michael P. Rogalski , Saulo Martelli , Marcus G. Pandy , Mariana E. Kersh","doi":"10.1016/j.jbiomech.2025.112743","DOIUrl":"10.1016/j.jbiomech.2025.112743","url":null,"abstract":"<div><div>Despite the benefits of exercise for bone health, the development of protocols to improve bone quality in fracture prone areas remains a challenge because of the difficulty in determining how bone is loaded <em>in vivo</em>. Discussions persist regarding whether the femoral neck is in bending or compression and the degree to which muscle forces contribute to loading. We simulated the loads during walking using subject-specific muscle-driven finite element models and compared three loading configurations: [1] all hip-spanning muscle and joint forces, [2] a sub-set of hip muscle and joint forces, and [3] hip joint forces only. We found that the use of the hip joint contact force alone resulted in large tensile and compressive principal strains. However, including muscle forces resulted in significantly decreased strain magnitudes and a change of mode to uneven compression in the femoral neck suggesting that the inclusion of muscle forces offset the bending moment observed in a hip-joint-force-only model. In the pertrochanter, including hip muscle forces increased the compressive and tensile strains. Together, these findings indicate that including hip-spanning muscle forces changes the mode and distributions of strains in the femoral neck as well as strain magnitudes in the pertrochanter. Future studies will benefit from including both muscle and joint reaction forces in simulations of bone under <em>in vivo</em> loading conditions in order to develop informed exercise interventions to improve bone health.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112743"},"PeriodicalIF":2.4,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169238","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

Using musculoskeletal models to estimate the effects of exoskeletons on spine loads during dynamic lifting tasks: differences between OpenSim and the AnyBody modelling system 使用肌肉骨骼模型来估计在动态举重任务中外骨骼对脊柱负荷的影响：OpenSim和任何人建模系统之间的差异

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-23 DOI: 10.1016/j.jbiomech.2025.112780

Mohamad Behjati Ashtiani , Mohammadhossein Akhavanfar , Lingyu Li , Sunwook Kim , Maury A Nussbaum

{"title":"Using musculoskeletal models to estimate the effects of exoskeletons on spine loads during dynamic lifting tasks: differences between OpenSim and the AnyBody modelling system","authors":"Mohamad Behjati Ashtiani , Mohammadhossein Akhavanfar , Lingyu Li , Sunwook Kim , Maury A Nussbaum","doi":"10.1016/j.jbiomech.2025.112780","DOIUrl":"10.1016/j.jbiomech.2025.112780","url":null,"abstract":"<div><div>Occupational back-support exoskeletons (BSEs) can reduce physical demands during lifting by providing assistive torques, but their effects on spine loading are poorly understood. In this study, we used two common musculoskeletal models developed in OpenSim and the AnyBody Modeling System to estimate intervertebral joint forces (IJF) during asymmetric and symmetric lifting tasks with and without BSEs. Data from an earlier study were used, involving 18 participants who performed repetitive lowering/lifting in three task conditions and with three different BSEs (along with a control condition using no BSE). We simulated the tasks with both models and estimated axial compression and anteroposterior shear forces at the L4/L5 joint and derived peak values (95th percentile) as outcome measures. OpenSim estimated significantly larger axial compression and anteroposterior shear forces than AMS. Both models estimated reductions in spine loading when using either of the BSEs, though OpenSim estimated greater reductions than AMS. Strong positive, linear relationships (<em>r</em> > 0.95) between the two model estimates were found for axial compression, while much weaker and even negative relationships were observed for shear forces, especially under asymmetric conditions. The differences in model estimates were likely due to variations in model assumptions and passive tissue representations. Future research should explore more detailed human-exoskeleton interaction models, evaluate the impact of modelling assumptions on IJF estimates, and assess the agreement of these findings with <em>in vivo</em> measurements such as electromyography.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112780"},"PeriodicalIF":2.4,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144146967","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

A novel markerless gait analysis method to detect alterations in inter-joint coupling patterns of human foot during cross-slope walking 一种新的无标记步态分析方法来检测人足在跨坡行走时关节间耦合模式的变化

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-23 DOI: 10.1016/j.jbiomech.2025.112766

Jie-Wen Li , Xin Ma , Wen-Ming Chen

{"title":"A novel markerless gait analysis method to detect alterations in inter-joint coupling patterns of human foot during cross-slope walking","authors":"Jie-Wen Li , Xin Ma , Wen-Ming Chen","doi":"10.1016/j.jbiomech.2025.112766","DOIUrl":"10.1016/j.jbiomech.2025.112766","url":null,"abstract":"<div><div>Walking on uneven surfaces alters foot joint kinematics and challenges gait stability. The intricate joint coupling relationship of the human foot, which is essential for biomechanical adaptations, particularly when encountering uneven surfaces, remains unclear. This study focused on quantifying foot joint coordination on cross-slopes using a markerless gait analysis method. Twelve healthy subjects performed walking tests on a gait platform under level, 8° everted and 8° inverted surface conditions. Segmental motion between rearfoot, midfoot, forefoot, and hallux were analyzed using a point cloud-based multi-segment foot model (MSFM). Adaptive changes of multi-segmental foot kinematics and inter-joint coupling relationships were compared across different cross-slope conditions. The results indicated that the rearfoot dominated frontal plane motion during everted surface walking in both middle and late stance, while the forefoot and midfoot dominated during inverted surface walking, respectively. In contrast to level walking, the sagittal-plane motion of the midtarsal joints during everted and inverted surface walking did not significantly contribute to foot kinematics at push-off. Further analysis reveals that significant variabilities exist in joint coupling behavior at different phases of the cross-slope walking.These findings demonstrate the effectiveness of the proposed method in detecting the complex inter-joint kinematics and coupling patterns of the human foot during cross-slope walking. The results provide insights into the kinematic changes of foot joints for terrain adaptation in uneven walking surfaces and advocate the application of novel motion analysis methods for tracking natural gait patterns.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112766"},"PeriodicalIF":2.4,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169245","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

Freezing negatively impacts the interlamellar mechanical properties of the degenerated human annulus fibrosus 冷冻对退行性人纤维环的层间力学性能有负面影响

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2025-05-22 DOI: 10.1016/j.jbiomech.2025.112779

Manmeet S. Dhiman , Mohammed A. Salaam , Taylor J. Bader , W.Bradley Jacobs , Kenneth C. Thomas , Paul T. Salo , David A. Hart , Ganesh Swamy , Neil A. Duncan

{"title":"Freezing negatively impacts the interlamellar mechanical properties of the degenerated human annulus fibrosus","authors":"Manmeet S. Dhiman , Mohammed A. Salaam , Taylor J. Bader , W.Bradley Jacobs , Kenneth C. Thomas , Paul T. Salo , David A. Hart , Ganesh Swamy , Neil A. Duncan","doi":"10.1016/j.jbiomech.2025.112779","DOIUrl":"10.1016/j.jbiomech.2025.112779","url":null,"abstract":"<div><div>Mechanical testing of biological tissues often utilizes previously frozen samples but there are conflicting reports about the impact of freezing on mechanical properties. There are no current studies examining the impact of freezing on the interlamellar matrix in the annulus fibrosus of intervertebral disc. We quantified the freezing-induced changes in the interlamellar mechanical properties of degenerated human and non-degenerated bovine annulus fibrosus tissues. Fresh human annulus fibrosus samples were obtained from surgical cases involving disc degeneration (loss of disc height with no deformities), degenerative scoliosis, degenerative spondylolisthesis, and isthmic spondylolisthesis, while bovine samples served as controls. The fresh samples were tested immediately following tissue resection whereas frozen samples were stored at −20 °C for three weeks before testing. An interlamellar peel test was performed where the lamellae were peeled at 0.5 mm/s until complete separation. In paired (same individual) and unpaired (different individuals) degenerated human samples, frozen tissues showed statistically significant decreases: Peel Stiffness (50 % and 36 %), Peel Strength (37 % and 45 %), and Standard Deviation of Peel Stress in the Peel Region (57 % and 55 %), with decreasing trends for Peel Toughness (41 % and 42 %), compared to fresh tissues. In contrast, non-degenerated bovine paired samples showed no significant differences between fresh and frozen groups. The results suggest that freezing negatively impacts interlamellar matrix properties in degenerated human annulus fibrosus, which may be exacerbated by existing tissue defects. In the future, annulus fibrosus samples may be best tested fresh to fully capture mechanical differences of the interlamellar matrix between clinical groups.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"188 ","pages":"Article 112779"},"PeriodicalIF":2.4,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134055","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