Journal of biomechanics最新文献_第2页

Articular chondrocytes from the knee and ankle have different sensitivities to shear strain 膝关节和踝关节软骨细胞对剪切应变的敏感性不同。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-05-01 Epub Date: 2026-03-03 DOI: 10.1016/j.jbiomech.2026.113237

Steven Ayala , Michelle L. Delco , Lisa A. Fortier , Itai Cohen , Lawrence J. Bonassar

{"title":"Articular chondrocytes from the knee and ankle have different sensitivities to shear strain","authors":"Steven Ayala , Michelle L. Delco , Lisa A. Fortier , Itai Cohen , Lawrence J. Bonassar","doi":"10.1016/j.jbiomech.2026.113237","DOIUrl":"10.1016/j.jbiomech.2026.113237","url":null,"abstract":"<div><div>Traumatic injury to synovial joints results in focal defects and proinflammatory changes in cartilage tissue, eventually leading to post-traumatic osteoarthritis (PTOA). Additionally, disparate incidence rates of PTOA occur between joints, particularly the knee and ankle. We hypothesize that differences in PTOA rates between knee and ankle cartilage are related to inherent differences in mechanical properties and chondrocyte sensitivity to mechanical loads. Our objective was to compare the effect of injury on the spatial patterns of cellular response between knee and ankle cartilage and relate these responses to changes in tissue mechanical properties. Cartilage explants of neonatal bovids from the talar dome of the ankle and femoral condyle of the knee were subjected to our ex vivo combined injury model which combines rapid impact injury and repetitive cartilage articulation. Explants were bisected and fluorescently stained to assess global and depth-dependent cell death, caspase activity, and mitochondrial depolarization. Explants were tested via confocal elastography to determine the local shear strain and shear modulus profile. Results showed that chondrocyte response differed between joints, with knee cartilage showing greater damage within the surface region. Additionally, ankle cartilage experienced a greater decrease in shear modulus post-injury compared to knee, causing depth-dependent shear strain to significantly increase (<em>p</em> < 0.0287). Furthermore, regression analyses relating cellular response to local shear strain revealed joint-specific differences in chondrocyte sensitivity, defined as the slope of cellular response versus shear strain, for cell death (knee: 873 vs ankle: 551), apoptosis (knee: 7779 vs ankle: 3577), and MT depolarization (knee: 848 vs ankle: 535).</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"200 ","pages":"Article 113237"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147377378","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

Average rotation matrices for converting scapula- and glenoid-based coordinate systems to ISB recommendations 将基于肩胛骨和关节的坐标系转换为ISB推荐坐标系的平均旋转矩阵。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-02-17 DOI: 10.1016/j.jbiomech.2026.113219

Florent Moissenet , Benjamin Michaud , Pierre Puchaud , Nicola Hagemeister , Mickaël Begon , Nicolas Holzer

{"title":"Average rotation matrices for converting scapula- and glenoid-based coordinate systems to ISB recommendations","authors":"Florent Moissenet , Benjamin Michaud , Pierre Puchaud , Nicola Hagemeister , Mickaël Begon , Nicolas Holzer","doi":"10.1016/j.jbiomech.2026.113219","DOIUrl":"10.1016/j.jbiomech.2026.113219","url":null,"abstract":"<div><div>Defining bone-embedded local coordinate systems (LCSs) is fundamental in shoulder biomechanics, yet multiple scapular LCSs exist, hindering data comparison. Although the International Society of Biomechanics (ISB) has published recommendations, alternative definitions based on distinct anatomical landmarks remain often used. To address these inconsistencies, average rotation matrices were recently proposed to convert between the three most common scapular LCSs, thereby facilitating comparison, merging, and interoperability between datasets. Building upon this, we have extended the approach to 11 scapular LCSs reported in the literature, including scapula- and glenoid-based systems. Using statistical shape models derived from 80 participants (asymptomatic and pathological shoulders), 1000 scapulae were generated to quantify geometric transformations between LCSs. Average rotation matrices were computed for each alternative system relative to the ISB-recommended LCS, and accuracy was assessed using helical angles. The application of the average rotation matrices substantially reduced the maximal discrepancies between LCSs, from 21.9° to 5.2°. Scapula-based systems exhibited lower discrepancies than glenoid-based ones, reflecting greater morphological variability in the glenoid region. Comparisons with previously published matrices showed minimal differences (<3°), supporting the robustness of the approach across various datasets and population. These findings confirm that average rotation matrices provide a reliable means of harmonising scapular kinematic data across studies, even if experimenters initially chose a different LCS. This work offers a simple framework, for bridging existing scapular kinematic datasets and promoting interoperability datasets in shoulder biomechanics research.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113219"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146776386","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

The use of residual lower limb –prosthetic socket interface pressure measurements to inform clinical decisions: A systematic review 残肢-义肢窝界面压力测量用于临床决策：一项系统综述。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-01-25 DOI: 10.1016/j.jbiomech.2026.113187

Lucy Armitage , Kenny Cho , Tawnee L. Sparling , Todd Sleeman , Gursel Alici , Manish Sreenivasa

{"title":"The use of residual lower limb –prosthetic socket interface pressure measurements to inform clinical decisions: A systematic review","authors":"Lucy Armitage , Kenny Cho , Tawnee L. Sparling , Todd Sleeman , Gursel Alici , Manish Sreenivasa","doi":"10.1016/j.jbiomech.2026.113187","DOIUrl":"10.1016/j.jbiomech.2026.113187","url":null,"abstract":"<div><div>This systematic review aims to synthesise and consolidate existing knowledge on the relationship between socket interface pressure measurement and outcome measures related to clinical parameters of socket comfort in lower-limb prosthetic sockets. A search of Scopus, Web of Science, MEDLINE, CINAHL, Cochrane database of systematic reviews and IEEE Xplore was performed up to 2nd August 2024. A total of 19 studies were included in the data extraction and quality assessment process. Most studies were moderate to high quality. Extracted data included a variety of sensing systems, predominantly on male subjects with transtibial amputation, measuring normal forces or pressure. Loads were associated with comfort, discomfort, satisfaction, pain onset or pain tolerance, tissue safety and changes to satisfaction over time. There were no studies reporting any of these outcomes for people with impaired sensation or phantom limb pain. Although, there was no consistent identifiable threshold associated with a comfort or discomfort condition for any region or activity between studies, measurements at some bony regions during dynamic or activity associated with higher interface loading allowed differentiation between comfortable and uncomfortable socket conditions across studies. The synthesis of the reported pressure measurements could be a starting point for the iterative process of developing tissue-safe pressure thresholds or ranges for use in long term socket fit monitoring or to assist clinicians and prosthesis users in defining socket fit and comfort.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113187"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147306205","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

Running with an exotendon reduces compressive knee contact force 使用外肌腱跑步可以减少膝关节的压缩接触力。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-02-13 DOI: 10.1016/j.jbiomech.2026.113217

Jon Stingel , Nicos Haralabidis , Jennifer Hicks , Scott Uhlrich , Scott Delp

{"title":"Running with an exotendon reduces compressive knee contact force","authors":"Jon Stingel , Nicos Haralabidis , Jennifer Hicks , Scott Uhlrich , Scott Delp","doi":"10.1016/j.jbiomech.2026.113217","DOIUrl":"10.1016/j.jbiomech.2026.113217","url":null,"abstract":"<div><div>An exotendon—a spring that couples the legs when attached to a runner’s shoes—reduces the energetic cost of running, but the effects on joint contact forces are unknown. This study examined whether running with an exotendon alters the forces in the hip, knee and ankle. We used muscle-driven simulations of experimental data to compute compressive and shear contact forces at the hip, knee, and ankle joints for seven participants running at 2.7 m/s with and without an exotendon. We found that runners using the exotendon experienced a 8.4% reduction in peak knee compressive contact force (1.0 ± 0.7 BW; <em>P</em> = 0.026), and no change in the peak knee shear contact force. The primary contributor to this reduction was lower forces in the quadriceps muscles, which decreased their contribution to peak knee compressive contact force by 12.2% (−0.8 ± 0.7 BW; <em>P</em> = 0.018). We observed no change in the peak compressive or shear contact forces in the hip or ankle joints. Though the exotendon was not originally designed to reduce joint forces, our findings highlight the ability of this simple device to make changes to gait that reduce both energetic cost and compressive knee force.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113217"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147306253","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

Dynamic regulation of Lower-Limb joint loading during Foot-Abducted landing in wide Lunge: An analysis of muscle synergy and neuromuscular activation patterns 下肢关节负荷的动态调节在足外蹬大箭步着地：肌肉协同和神经肌肉激活模式的分析。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-02-26 DOI: 10.1016/j.jbiomech.2026.113231

Yanlong Zhang , Yanyu Yin , Xiao Yu , Minghe Sun , Gengchao Bi , Si Chen

{"title":"Dynamic regulation of Lower-Limb joint loading during Foot-Abducted landing in wide Lunge: An analysis of muscle synergy and neuromuscular activation patterns","authors":"Yanlong Zhang , Yanyu Yin , Xiao Yu , Minghe Sun , Gengchao Bi , Si Chen","doi":"10.1016/j.jbiomech.2026.113231","DOIUrl":"10.1016/j.jbiomech.2026.113231","url":null,"abstract":"<div><div>This study compares the relative contribution of knee joint medial and lateral compartmental loading, muscle synergy, and activation characteristics between two types of wide-lunge landing strategies to reveal the neuromuscular mechanisms by which foot-abducted landings reduce injury risk. Twenty male badminton players performed the lunge with two foot orientations: heel-to-second metatarsal (foot-forward) and 20° foot abduction (foot-abducted). The foot-abducted landing significantly reduced medial compartment peak shear force and pressure contributions from the semitendinosus, vastus medialis, and vastus lateralis (P < 0.05). It also decreased lateral compartment moments and muscle contributions from the biceps femoris, rectus femoris, and medial gastrocnemius (P < 0.05). Among the four identified muscle synergies, Syn1 was primarily active before landing. In foot-abducted landings, Syn2 exhibited higher activation of the vastus medialis and vastus lateralis (P < 0.05), while Syn3 showed greater gastrocnemius involvement (P < 0.05). Additionally, the co-activation index indicated higher gastrocnemius activity in foot-abducted landings (P < 0.05). These findings suggest that landing with foot abduction and initial lateral heel contact realigns force vectors, reducing knee joint loading. This strategy promotes a shift from single-joint control to a multi-joint kinetic-chain synergy, demonstrating a neuromuscular pattern associated with lower injury risk.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113231"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147326012","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

Quantifying differences in high-pressure region mapping between dynamic in-shoe and barefoot plantar pressure in diabetic subjects 糖尿病患者动态鞋内足底压力与赤脚足底压力之间高压区映射的量化差异。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-02-08 DOI: 10.1016/j.jbiomech.2026.113201

Dylan Heino , Scott Telfer , Avocet Nagle-Christensen , William R. Ledoux , Brittney C. Muir

{"title":"Quantifying differences in high-pressure region mapping between dynamic in-shoe and barefoot plantar pressure in diabetic subjects","authors":"Dylan Heino , Scott Telfer , Avocet Nagle-Christensen , William R. Ledoux , Brittney C. Muir","doi":"10.1016/j.jbiomech.2026.113201","DOIUrl":"10.1016/j.jbiomech.2026.113201","url":null,"abstract":"<div><div>Foot ulceration is a serious complication of diabetes, often linked to elevated forefoot pressures during walking. Custom accommodative insoles reduce peak plantar pressures, with greater reductions achieved when dynamic pressure data informs design. While in-shoe and barefoot data are used separately to design insoles, their agreement in pressure distribution and high-pressure region location has not been evaluated. This study compares pressure distribution and high-pressure region mapping between in-shoe and barefoot data.</div><div>In-shoe and barefoot pressures were recorded during walking for 25 feet from 16 individuals with high forefoot pressures. High-pressure regions were masked, grouped, and labeled by anatomical region. In-shoe and barefoot pressure maps were averaged over trials and overlaid, and peak pressure and contact area were calculated for all high-pressure regions. For matched regions, centroid locations were compared.</div><div>In-shoe high-pressure regions (>200 kPa) were typically observed in similar locations to barefoot walking, while barefoot maps often identified additional regions (>450 kPa) in the toes and lateral forefoot. For in-shoe data, these regions had lower peak pressures and larger contact areas. Matched regions’ centroid positions differed by 0.23–0.60 cm.</div><div>Key loading areas were consistent between systems, though unmatched regions were common, particularly in barefoot data, reflecting greater sensitivity to localized pressures. Barefoot data may overestimate high-risk regions that do not display elevated in-shoe pressures. Basing offloading insole design on threshold-based barefoot high-pressure regions could reduce specificity and limit pressure reduction for in-shoe high-pressure regions. These findings have potential implications for streamlining clinical workflows during pressure-informed insole design.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113201"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147348343","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

The influence of lower limb kinematic characteristics in stroke patients on gait speed mediated by paretic side propulsive force 脑卒中患者下肢运动特征对瘫侧推进力介导的步态速度的影响。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-02-18 DOI: 10.1016/j.jbiomech.2026.113220

Haruna Ukigai , Yuichiro Hosoi , Takayuki Kamimoto , Junsuke Ito , Arisa Kawabata , Kohsuke Okada , Kohshiro Haruyama , Tetsuya Tsuji , Michiyuki Kawakami

{"title":"The influence of lower limb kinematic characteristics in stroke patients on gait speed mediated by paretic side propulsive force","authors":"Haruna Ukigai , Yuichiro Hosoi , Takayuki Kamimoto , Junsuke Ito , Arisa Kawabata , Kohsuke Okada , Kohshiro Haruyama , Tetsuya Tsuji , Michiyuki Kawakami","doi":"10.1016/j.jbiomech.2026.113220","DOIUrl":"10.1016/j.jbiomech.2026.113220","url":null,"abstract":"<div><div>The relationships among gait speed, paretic side propulsive force (PPF), and kinematic characteristics in stroke patients remain unclear. This study retrospectively analyzed data from 109 post-stroke patients to identify kinematic characteristics influencing gait speed mediated by PPF. Motion capture system was used for measuring ground walking, and hip, knee, and ankle joint angle during stance phase of paretic side were extracted. The joint angle data were classified into four phases (the initial double-support (Phase 1), the first and second 50% of the single-leg stance (Phase 2, Phase 3), the second double-support (Phase 4)), and average angle of the time series for each phase was calculated (kinematic variables). Comfortable gait speed (CGS) and PPF were also averaged. Statistical analysis first performed correlation analysis between CGS, PPF and kinematic variables. Next, mediation analysis was conducted using kinematic variables as independent variables, CGS as dependent variable, and PPF as mediating variable. Correlation analysis revealed that the kinematic variables of hip and knee joints in all phases, and ankle joint in Phase 3, showed significant correlations with CGS and PPF. For mediation analysis, the mediation model with only indirect effects significant was established for the following variables: hip extension (Total Effect (TE) = − 0.007, p = 0.018), knee flexion (TE = 0.010, p < 0.01), and ankle dorsiflexion (TE = 0.013, p < 0.01) in Phases 3 and hip extension in Phase 4 (TE = − 0.011, p < 0.01). These four kinematic variables were each found to influence gait speed mediated by PPF. In gait intervention, focusing on these joint movements during mid-to-late stance phase is important.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113220"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147271089","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

Corrigendum to “The impact of backpack load on adolescent stair descent safety and injury risk” [J. Biomech. 166 (2024) 112029] “背包载荷对青少年下楼梯安全及伤害风险的影响”[J]。生物医学学报，2016,32(2):1158 - 1158。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-02-17 DOI: 10.1016/j.jbiomech.2026.113215

Zijun Lu, Chuangui Mao, Yuanyuan Tan, Tao Liu, Xinglu Li, Zhengao Li, Wenfei Zhu, Yuliang Sun

{"title":"Corrigendum to “The impact of backpack load on adolescent stair descent safety and injury risk” [J. Biomech. 166 (2024) 112029]","authors":"Zijun Lu, Chuangui Mao, Yuanyuan Tan, Tao Liu, Xinglu Li, Zhengao Li, Wenfei Zhu, Yuliang Sun","doi":"10.1016/j.jbiomech.2026.113215","DOIUrl":"10.1016/j.jbiomech.2026.113215","url":null,"abstract":"<div><div>This study investigates the impact of increasing backpack load on the gait of adolescents during stair descent. Sixteen healthy male students (age = 12.9 ± 0.6 years) were required to descend the stairs in 4 loaded conditions. The kinematic, kinetic, and EMG data were collected synchronously and gait parameters, especially indicators of balance control, were analyzed. The posterior tilt angles (COM-COP IA in the sagittal plane) (0%–42%, 48%–53%, 58%–91%, p < 0.01), trunk anterior tilt angles (9–33%, 51–65%, p < 0.01), and CV of stride length (p < 0.01) increased with the backpack load. The COM-Step edge separation decreased with the increased backload (p < 0.01). In addition, the hip flexion torque (25–40%, 45–51%, p < 0.01), the rectus femoris activation, and the hip stiffness increased significantly as the load up to 15% Body Weight (BW)and 20% BW. The increasing backpack load may affect adolescent’s stair descent gait. Especially as the load was up to 15% BW, the adolescents’ bodies tended to tilt backwards relative to the support foot during the single stance phase. They may activate the hip flexors and tilt forward the trunk to recover from the balance perturbation, which was associated with increased hip flexion torques. This adjustment was more pronounced with the increasing backpack load. However, excessive forward flexion may increase the risk of forward falls. The boundaries of adjustment need further research in the future. Findings from this study provide baseline information on the intrinsic mechanisms of balance control during stair descent.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113215"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147283903","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

Mesenchymal stem cells differentiate dynamic from static load through variable regulation of the Hippo pathway 间充质干细胞通过Hippo通路的可变调节从静态负荷分化为动态负荷。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-02-21 DOI: 10.1016/j.jbiomech.2026.113228

Zhihui Xie , Buer Sen , Nina Nikitina , Sean Howard , Maya Styner , Clinton Rubin , Gunes Uzer , Janet Rubin

{"title":"Mesenchymal stem cells differentiate dynamic from static load through variable regulation of the Hippo pathway","authors":"Zhihui Xie , Buer Sen , Nina Nikitina , Sean Howard , Maya Styner , Clinton Rubin , Gunes Uzer , Janet Rubin","doi":"10.1016/j.jbiomech.2026.113228","DOIUrl":"10.1016/j.jbiomech.2026.113228","url":null,"abstract":"<div><div>The mechanical environment of a cell, which profoundly influences cell behaviors, includes loading parameters such as magnitude, rate cycle number and duration. Time-varying, or dynamic, levels of load are generally associated with anabolic responses, while time invariant, or static, forces often increase catabolic pathophysiology. How cells differentiate between static and dynamic loading parameters is unclear. In mesenchymal stem cells (MSC), we found that static strain (SS) increased nuclear YAP at 3 h, whereas 200 cycles of dynamic strain (DS) did not. Differences in nuclear YAP were directed by phosphorylation of Hippo enzymes: SS promoted association of PP2Ac dephosphorylase with nuclear MST1/2. In contrast, DS activated Hippo signaling with phosphorylation of MST1/2 and YAP. Actin remodeling was differentially affected by DS and SS: DS generated thicker fibers with greater cross-sectional area and enhanced parallel alignment. In contrast, static strain reinforced the existing isotropic actin network by increasing fiber density and focal adhesion count. DS induced actin remodeling was associated with phosphorylation of both LATS1/2 and AMOT, which binds both actin and nuclear MST1/2. When LATS1/2 was inhibited, or AMOT was knocked down, nuclear PP2Ac increased and YAP was dephosphorylated. This suggests that DS induced actin remodeling provokes release of phosphorylated AMOT from actin binding sites, while SS induced actin reinforcement sequesters AMOT. In sum, our data shows that MSC are equipped to differentiate between load components, resulting in nuanced mechanical effects on the Hippo pathway.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113228"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147306224","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 infraglottal implantation on voice production in type I thyroplasty: a computational study 喉内植入对I型甲状腺成形术中声音产生的影响：一项计算研究。

IF 2.4 3区医学

Journal of biomechanics Pub Date : 2026-04-01 Epub Date: 2026-02-27 DOI: 10.1016/j.jbiomech.2026.113234

Weili Jiang , Charles Farbos de Luzan , Liran Oren , Ephraim Gutmark , Xudong Zheng , Qian Xue

{"title":"Effects of infraglottal implantation on voice production in type I thyroplasty: a computational study","authors":"Weili Jiang , Charles Farbos de Luzan , Liran Oren , Ephraim Gutmark , Xudong Zheng , Qian Xue","doi":"10.1016/j.jbiomech.2026.113234","DOIUrl":"10.1016/j.jbiomech.2026.113234","url":null,"abstract":"<div><div>Type I thyroplasty (TT1) is one of the primary phonosurgical interventions for unilateral vocal fold paralysis. This study investigated the effects of infraglottal implant placement in TT1 on voice production using numerical simulations. The laryngeal and implant geometries were reconstructed from computed tomography scan of a canine larynx with a hand-carved Silastic implant. Fluid–structure interaction simulations, coupling the continuum finite element vocal fold and implant models with a one-dimensional Bernoulli-based glottal flow model, were conducted to evaluate vocal fold vibration across a range of implant stiffnesses, insertion depths, and vertical positions. Effects of implant parameters on pre-phonatory shape and stiffness, glottal flow and vocal fold dynamics and acoustic outcome have been analyzed. The results revealed that infraglottal implants can enhance both sound pressure level (SPL) and vocal efficiency (VE) when the insertion depth exceeds a certain threshold. The observed enhancement in SPL and VE was attributed to an increased vertical stiffness gradient in the vocal folds induced by the inferior implant, which leads to greater force asymmetry between vocal folds opening and closing, thereby promoting more effective energy transfer from the glottal airflow to the vocal folds. The result is larger vocal fold vibrations, which leads to a larger SPL and may also contribute to the improved VE. The current simulation is based on the simulation of one single canine larynx. Future studies incorporating more subjects would help to generalize the current findings.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"199 ","pages":"Article 113234"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147326169","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