Journal of biomechanics最新文献_第3页

Endothelial cytoskeleton in mechanotransduction and vascular diseases

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-09 DOI: 10.1016/j.jbiomech.2025.112579

Linlu Jin, Yixue Qin, Yunran Zhao, Xintong Zhou, Ye Zeng

The cytoskeleton is an important structural component that regulates various aspects of cell morphology, movement, and intracellular signaling. It plays a pivotal role in the cellular response to biomechanical stimuli, particularly in endothelial cells, which are critical for vascular homeostasis and the pathogenesis of cardiovascular diseases. Mechanical forces, such as shear and tension, activate intracellular signaling cascades that regulate transcription, translation, and cellular behaviors. Despite extensive research into cytoskeletal functions, the precise mechanisms by which the cytoskeleton transduces mechanical signals remain incompletely understood. This review focuses on the role of cytoskeletal components in membrane, cytoplasm, and nucleus in mechanotransduction, with an emphasis on their structure, mechanical and biological behaviors, dynamic interactions, and response to mechanical forces. The collaboration between membrane cytoskeleton, cytoplasmic cytoskeleton, and nucleoskeleton is indispensable for endothelial cells to respond to mechanical stimuli. Understanding their mechanoresponsive mechanisms is essential for advancing therapeutic strategies for cardiovascular diseases.

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引用次数: 0

Three-dimensional continuous muscle moment arm maps for the anatomical shoulder 解剖肩部的三维连续肌肉力矩臂图

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-08 DOI: 10.1016/j.jbiomech.2025.112561

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

A muscle’s moment arm represents its mechanical advantage and indicates its role in joint actuation and rotational stability. The objective of this study was to use an ex-vivo simulator to map the moment arms of eight major shoulder muscles across a continuous range of motion. The three-dimensional moment arms for the deltoid (anterior, lateral, and posterior), subscapularis (inferior and superior), supraspinatus, infraspinatus, and teres minor were measured in eight specimens (57 ± 6 years) using the tendon excursion method. The anterior deltoid had a significantly larger elevation moment arm in anterior planes of elevation (p < 0.001) while the lateral deltoid had a significantly larger elevation moment arm in posterior planes (p < 0.001). The posterior deltoid was an antagonist to elevation with anterior arm orientations (p < 0.001). The supraspinatus had biphasic function; in anterior elevation planes it was a horizontal extensor and internal rotator but was a horizontal flexor and external rotator in posterior planes (p < 0.001). The infraspinatus and superior subscapularis were both arm elevators, but the infraspinatus was an external rotator and horizontal extensor while the superior subscapularis was an internal rotator and horizontal flexor. The inferior subscapularis was a horizontal flexor and internal rotator while the teres minor was an antagonist to elevation, horizontal extensor, and external rotator. Each muscle had a multifaceted function which changed significantly with arm orientation for all muscles except the inferior subscapularis. The muscle moment arms maps created in this study improve current understandings of the three-dimensional function of eight major muscles in the shoulder.

{"title":"Three-dimensional continuous muscle moment arm maps for the anatomical shoulder","authors":"David T. Axford , Robert Potra , Richard Appleyard , Janos Tomka , Antonio Arenas-Miquelez , David Hollo , Sumit Raniga , Louis M. Ferreira","doi":"10.1016/j.jbiomech.2025.112561","DOIUrl":"10.1016/j.jbiomech.2025.112561","url":null,"abstract":"<div><div>A muscle’s moment arm represents its mechanical advantage and indicates its role in joint actuation and rotational stability. The objective of this study was to use an ex-vivo simulator to map the moment arms of eight major shoulder muscles across a continuous range of motion. The three-dimensional moment arms for the deltoid (anterior, lateral, and posterior), subscapularis (inferior and superior), supraspinatus, infraspinatus, and teres minor were measured in eight specimens (57 ± 6 years) using the tendon excursion method. The anterior deltoid had a significantly larger elevation moment arm in anterior planes of elevation (p < 0.001) while the lateral deltoid had a significantly larger elevation moment arm in posterior planes (p < 0.001). The posterior deltoid was an antagonist to elevation with anterior arm orientations (p < 0.001). The supraspinatus had biphasic function; in anterior elevation planes it was a horizontal extensor and internal rotator but was a horizontal flexor and external rotator in posterior planes (p < 0.001). The infraspinatus and superior subscapularis were both arm elevators, but the infraspinatus was an external rotator and horizontal extensor while the superior subscapularis was an internal rotator and horizontal flexor. The inferior subscapularis was a horizontal flexor and internal rotator while the teres minor was an antagonist to elevation, horizontal extensor, and external rotator. Each muscle had a multifaceted function which changed significantly with arm orientation for all muscles except the inferior subscapularis. The muscle moment arms maps created in this study improve current understandings of the three-dimensional function of eight major muscles in the shoulder.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"182 ","pages":"Article 112561"},"PeriodicalIF":2.4,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of the relationship between soft tissue stiffness and maximum knee extension angle in patients with knee osteoarthritis

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.jbiomech.2025.112582

Sayaka Okada , Masahide Yagi , Masashi Taniguchi , Yoshiki Motomura , Shogo Okada , Yoshihiro Fukumoto , Masashi Kobayashi , Kyoseki Kanemitsu , Noriaki Ichihashi

Knee extension limitation is a risk factor for knee osteoarthritis (OA) progression. However, the soft tissue stiffness involved in knee extension limitation remains to be determined. This study aimed to clarify the relationship between maximum knee extension angle and tissue stiffness in patients with knee OA using ultrasound shear wave elastography (uSWE). Women aged > 50 years with medial knee OA participated　in this study. We evaluated the maximum knee extension angle in the prone position using a goniometer at 1° increments. The shear wave velocity (SWV) in the prone position at 15° knee flexion of the following tissues was measured using uSWE: medial and lateral posterior capsule, medial collateral ligament, popliteus muscle, biceps femoris short head (middle and distal), and medial and lateral gastrocnemius (middle and proximal). We performed separate simple linear regression analyses with maximum knee extension angle as a dependent variable and the SWV of each tissue as an independent variable. A total of 66 participants were included in this study. The maximum knee extension angle was significantly positively associated with the SWV of medial posterior capsule (β = 0.31, p = 0.012). Conversely, the maximum knee extension angle was negatively associated with the SWV of the proximal medial gastrocnemius (β = -0.35, p < 0.01). There were no associations between other tissues and the maximum knee extension angle. Our results suggest that stiffness of the medial posterior capsule is associated with knee extension limitation in patients with Knee OA.

{"title":"Investigation of the relationship between soft tissue stiffness and maximum knee extension angle in patients with knee osteoarthritis","authors":"Sayaka Okada , Masahide Yagi , Masashi Taniguchi , Yoshiki Motomura , Shogo Okada , Yoshihiro Fukumoto , Masashi Kobayashi , Kyoseki Kanemitsu , Noriaki Ichihashi","doi":"10.1016/j.jbiomech.2025.112582","DOIUrl":"10.1016/j.jbiomech.2025.112582","url":null,"abstract":"<div><div>Knee extension limitation is a risk factor for knee osteoarthritis (OA) progression. However, the soft tissue stiffness involved in knee extension limitation remains to be determined. This study aimed to clarify the relationship between maximum knee extension angle and tissue stiffness in patients with knee OA using ultrasound shear wave elastography (uSWE). Women aged > 50 years with medial knee OA participated　in this study. We evaluated the maximum knee extension angle in the prone position using a goniometer at 1° increments. The shear wave velocity (SWV) in the prone position at 15° knee flexion of the following tissues was measured using uSWE: medial and lateral posterior capsule, medial collateral ligament, popliteus muscle, biceps femoris short head (middle and distal), and medial and lateral gastrocnemius (middle and proximal). We performed separate simple linear regression analyses with maximum knee extension angle as a dependent variable and the SWV of each tissue as an independent variable. A total of 66 participants were included in this study. The maximum knee extension angle was significantly positively associated with the SWV of medial posterior capsule (β = 0.31, p = 0.012). Conversely, the maximum knee extension angle was negatively associated with the SWV of the proximal medial gastrocnemius (β = -0.35, p < 0.01). There were no associations between other tissues and the maximum knee extension angle. Our results suggest that stiffness of the medial posterior capsule is associated with knee extension limitation in patients with Knee OA.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"182 ","pages":"Article 112582"},"PeriodicalIF":2.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378370","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

Hybrid discrete and finite element analysis enables fast evaluation of hip joint cartilage mechanical response

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-06 DOI: 10.1016/j.jbiomech.2025.112568

Mikko S. Venäläinen , Mao Li , Juha Töyräs , Rami K. Korhonen , Jurgen Fripp , Stuart Crozier , Shekhar S. Chandra , Craig Engstrom

Finite element analysis (FEA) is the leading numerical technique for studying joint biomechanics related to the onset and progression of osteoarthritis. However, subject-specific FEA of joint mechanics is a time- and compute-intensive process limiting its clinical applicability. We introduce and evaluate a novel hybrid modelling framework combining discrete element analysis (DEA) and FEA for computationally efficient evaluation of cartilage mechanics in the hip joint. In our approach, the hip joint contact mechanics are first estimated using DEA and subsequently used as input for matching FEA models, substantially reducing model complexity. The cartilage mechanical responses obtained using the hybrid DEA-FEA method were evaluated for subject-specific hip joint geometries from five asymptomatic individuals under loading conditions typical to normal walking gait and compared to conventional FEA in terms of peak intra-tissue mechanical stresses and model run-times. The hybrid DEA-FEA method had a median run-time of 3.6 min per subject (64-core processor, 512 GB RAM) and produced minimum principal (compressive) stress estimates comparable to stresses obtained using conventional FEA models with a median run-time of 96.2 min. On average, the peak compressive stresses obtained using the hybrid DEA-FEA approach were 0.06 MPa (95 % confidence interval: −0.86–0.99) lower than the stresses estimated with conventional FEA. Despite up to 1.4 MPa differences at individual gait time-points, the results indicate that the proposed hybrid DEA-FEA method enables estimation of hip cartilage mechanics in a fraction of time compared to conventional FEA, facilitating implementation in large cohort studies and clinical applications.

{"title":"Hybrid discrete and finite element analysis enables fast evaluation of hip joint cartilage mechanical response","authors":"Mikko S. Venäläinen , Mao Li , Juha Töyräs , Rami K. Korhonen , Jurgen Fripp , Stuart Crozier , Shekhar S. Chandra , Craig Engstrom","doi":"10.1016/j.jbiomech.2025.112568","DOIUrl":"10.1016/j.jbiomech.2025.112568","url":null,"abstract":"<div><div>Finite element analysis (FEA) is the leading numerical technique for studying joint biomechanics related to the onset and progression of osteoarthritis. However, subject-specific FEA of joint mechanics is a time- and compute-intensive process limiting its clinical applicability. We introduce and evaluate a novel hybrid modelling framework combining discrete element analysis (DEA) and FEA for computationally efficient evaluation of cartilage mechanics in the hip joint. In our approach, the hip joint contact mechanics are first estimated using DEA and subsequently used as input for matching FEA models, substantially reducing model complexity. The cartilage mechanical responses obtained using the hybrid DEA-FEA method were evaluated for subject-specific hip joint geometries from five asymptomatic individuals under loading conditions typical to normal walking gait and compared to conventional FEA in terms of peak intra-tissue mechanical stresses and model run-times. The hybrid DEA-FEA method had a median run-time of 3.6 min per subject (64-core processor, 512 GB RAM) and produced minimum principal (compressive) stress estimates comparable to stresses obtained using conventional FEA models with a median run-time of 96.2 min. On average, the peak compressive stresses obtained using the hybrid DEA-FEA approach were 0.06 MPa (95 % confidence interval: −0.86–0.99) lower than the stresses estimated with conventional FEA. Despite up to 1.4 MPa differences at individual gait time-points, the results indicate that the proposed hybrid DEA-FEA method enables estimation of hip cartilage mechanics in a fraction of time compared to conventional FEA, facilitating implementation in large cohort studies and clinical applications.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"182 ","pages":"Article 112568"},"PeriodicalIF":2.4,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The shear modulus of the vastus lateralis muscle does not follow the passive residual torque enhancement in the knee extensors

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-06 DOI: 10.1016/j.jbiomech.2025.112567

Gustavo Henrique Halmenschlager , José Carlos dos Santos Albarello , Maria Clara Albuquerque Brandão , Liliam Fernandes de Oliveira , Thiago Torres da Matta

In vitro experiments define passive force enhancement as the increase in steady-state passive force following the deactivation of an actively stretched muscle, in contrast to a purely passive stretch. This phenomenon, linked to residual force enhancement, is also observed in voluntarily contracted muscles as passive residual torque enhancement (RTE_pass). While mechanisms remain unclear, titin stiffness likey plays a key role. Supersonic shear wave elastography (SSI) estimates tissue stiffness via the shear modulus (μ). The study aimed to assess whether RTE_pass of the knee extensor muscles is accompanied by an increase in vastus lateralis stiffness (RμE_pass) as measured by shear wave elastography. Passive torque was measured in 20 healthy young adults at a knee flexion angle of 100° before and after both isometric contractions (control protocol) and isometric contractions preceded by an eccentric contraction at 30°/s (from 70° to 100°). The comparison of protocols revealed a significant mean RTE_pass of 1.03 N·m (16.5 %; p < 0.001), confirming the RTE_pass in knee extensors. Although the experimental protocol showed a significant change in μ from the Before- to Post-contraction moment (5.89 %; p = 0.041), no differences in μ were observed between protocols at any post-contraction moments (p ≥ 0.191). Spearman correlation analysis indicated a weak, non-significant correlation between RTE_pass and RμE_pass (rs = 0.219; p = 0.352). These findings suggest that changes in vastus lateralis stiffness, as measured by SSI, are insufficient to explain RTE_pass. While the literature identifies titin as a primary mechanism for passive residual torque enhancement, SSI elastography did not detect this phenomenon through solely vastus lateralis stiffness.

{"title":"The shear modulus of the vastus lateralis muscle does not follow the passive residual torque enhancement in the knee extensors","authors":"Gustavo Henrique Halmenschlager , José Carlos dos Santos Albarello , Maria Clara Albuquerque Brandão , Liliam Fernandes de Oliveira , Thiago Torres da Matta","doi":"10.1016/j.jbiomech.2025.112567","DOIUrl":"10.1016/j.jbiomech.2025.112567","url":null,"abstract":"<div><div><em>In vitro</em> experiments define passive force enhancement as the increase in steady-state passive force following the deactivation of an actively stretched muscle, in contrast to a purely passive stretch. This phenomenon, linked to residual force enhancement, is also observed in voluntarily contracted muscles as passive residual torque enhancement (RTE<sub>pass</sub>). While mechanisms remain unclear, titin stiffness likey plays a key role. Supersonic shear wave elastography (SSI) estimates tissue stiffness via the shear modulus (μ). The study aimed to assess whether RTE<sub>pass</sub> of the knee extensor muscles is accompanied by an increase in vastus lateralis stiffness (RμE<sub>pass</sub>) as measured by shear wave elastography. Passive torque was measured in 20 healthy young adults at a knee flexion angle of 100° before and after both isometric contractions (control protocol) and isometric contractions preceded by an eccentric contraction at 30°/s (from 70° to 100°). The comparison of protocols revealed a significant mean RTE<sub>pass</sub> of 1.03 N·m (16.5 %; <em>p</em> < 0.001), confirming the RTE<sub>pass</sub> in knee extensors. Although the experimental protocol showed a significant change in μ from the Before- to Post-contraction moment (5.89 %; <em>p</em> = 0.041), no differences in μ were observed between protocols at any post-contraction moments (<em>p</em> ≥ 0.191). Spearman correlation analysis indicated a weak, non-significant correlation between RTE<sub>pass</sub> and RμE<sub>pass</sub> (<em>r</em>s = 0.219; <em>p</em> = 0.352). These findings suggest that changes in vastus lateralis stiffness, as measured by SSI, are insufficient to explain RTE<sub>pass.</sub> While the literature identifies titin as a primary mechanism for passive residual torque enhancement, SSI elastography did not detect this phenomenon through solely vastus lateralis stiffness.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"182 ","pages":"Article 112567"},"PeriodicalIF":2.4,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403436","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 force-calcium relationship is not affected by the cross-sectional area of skinned muscle fibres from rat soleus

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-06 DOI: 10.1016/j.jbiomech.2025.112571

Ian C. Smith , Venus Joumaa , Walter Herzog

Proportionality between force and muscle cross-sectional area (CSA) is a foundational principle in muscle mechanics. However, CSA-normalized force (known as specific force) is often lower in fibres with large CSAs compared to fibres with small CSAs from the same sample population. Many physiological mechanisms proposed to account for CSA-dependence of specific force converge on the requirement for fibre CSA to impact the relationship between force and the concentration of force-activating calcium. To determine if features of the force-calcium relationship exhibited CSA-dependence in mammalian skinned muscle fibres, force-calcium relationships were generated for 85 skinned slow soleus fibres of male Sprague-Dawley rats (n = 54 rats, 1–5 fibres per rat, age = 24 weeks, experimental temperature = 18 °C) and fit using the Hill equation. Fibres were separated into quartiles based on their CSA and then compared. Despite specific force being 46 % higher (P < 0.01) in the smallest (160 ± 51 mN∙mm⁻²; CSA = 3649 ± 708 μm²) compared to the largest (110 ± 20 mN∙mm⁻²; CSA = 8671 ± 1319 μm²) quartile, neither the calcium-sensitivity of force production (pCa50; P = 0.47; F(dFn = 3,DFd = 81) = 0.86) nor the Hill coefficient (n_H; P = 0.38; F(dFn = 3,DFd = 81) = 1.03) differed significantly between quartiles (smallest quartile: pCa50 = 6.015 ± 0.097, n_H = 1.80 ± 0.69; largest quartile: pCa50 = 6.062 ± 0.097, n_H = 1.63 ± 0.32). Force plateaus were observed at higher calcium concentrations in all fibres indicating that calcium was adequate for full activation. These findings add to the body of evidence suggesting that CSA-dependence of specific force in mammalian skinned fibres is an artifact attributable to the considerable imprecision associated with the assessment of fibre CSA, and not a physiological phenomenon which would require consideration when modeling muscle force output.

{"title":"The force-calcium relationship is not affected by the cross-sectional area of skinned muscle fibres from rat soleus","authors":"Ian C. Smith , Venus Joumaa , Walter Herzog","doi":"10.1016/j.jbiomech.2025.112571","DOIUrl":"10.1016/j.jbiomech.2025.112571","url":null,"abstract":"<div><div>Proportionality between force and muscle cross-sectional area (CSA) is a foundational principle in muscle mechanics. However, CSA-normalized force (known as specific force) is often lower in fibres with large CSAs compared to fibres with small CSAs from the same sample population. Many physiological mechanisms proposed to account for CSA-dependence of specific force converge on the requirement for fibre CSA to impact the relationship between force and the concentration of force-activating calcium. To determine if features of the force-calcium relationship exhibited CSA-dependence in mammalian skinned muscle fibres, force-calcium relationships were generated for 85 skinned slow soleus fibres of male Sprague-Dawley rats (<em>n</em> = 54 rats, 1–5 fibres per rat, age = 24 weeks, experimental temperature = 18 °C) and fit using the Hill equation. Fibres were separated into quartiles based on their CSA and then compared. Despite specific force being 46 % higher (<em>P</em> < 0.01) in the smallest (160 ± 51 mN∙mm<sup>−2</sup>; CSA = 3649 ± 708 μm<sup>2</sup>) compared to the largest (110 ± 20 mN∙mm<sup>−2</sup>; CSA = 8671 ± 1319 μm<sup>2</sup>) quartile, neither the calcium-sensitivity of force production (pCa50; <em>P</em> = 0.47; <em>F</em>(dFn = 3,DFd = 81) = 0.86) nor the Hill coefficient (<em>n<sub>H</sub></em>; <em>P</em> = 0.38; <em>F</em>(dFn = 3,DFd = 81) = 1.03) differed significantly between quartiles (smallest quartile: pCa50 = 6.015 ± 0.097, <em>n<sub>H</sub></em> = 1.80 ± 0.69; largest quartile: pCa50 = 6.062 ± 0.097, <em>n<sub>H</sub></em> = 1.63 ± 0.32). Force plateaus were observed at higher calcium concentrations in all fibres indicating that calcium was adequate for full activation. These findings add to the body of evidence suggesting that CSA-dependence of specific force in mammalian skinned fibres is an artifact attributable to the considerable imprecision associated with the assessment of fibre CSA, and not a physiological phenomenon which would require consideration when modeling muscle force output.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"182 ","pages":"Article 112571"},"PeriodicalIF":2.4,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Step velocity asymmetry rather than step length asymmetry is updated in split-belt treadmill adaptation

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-06 DOI: 10.1016/j.jbiomech.2025.112564

Yuki Ishida , Hikaru Yokoyama , Naotsugu Kaneko , Tatsuya Kato , Kei-ichi Ishikawa , Kimikata Nakazawa , Ken Takiyama

When discrepancies between planned and actual movements arise due to environmental changes, humans adjust movement parameters to achieve task goals. While motor adaptation has been extensively studied, the mechanisms involved in redundant movement parameters remain unclear. Split-belt treadmill adaptation, where each belt moves at a different speed, is an example of this phenomenon. Such adaptation initially induces gait asymmetry, which diminishes over time. Previous studies have postulated step length asymmetry as the target function; however, recent evidence challenges this assumption, leaving the target function undefined. This study investigates the target function by analyzing step parameter asymmetry using the goal-equivalent manifold and generalization predictability. The goal-equivalent manifold assesses whether adaptation is close to optimal in minimizing step parameter asymmetry, while generalization predictability reflects adaptation effects across different contexts, indicating potential target functions. We propose that step velocity asymmetry, rather than step length asymmetry, serves as the target function in split-belt treadmill adaptation. This framework facilitates the prediction and interpretation of both the learning process and the transfer of learning effects from trained to untrained conditions. In addition, it explains the overadaptation of step length asymmetry and the achievement of energy-efficient gait after adaptation. Therefore, we propose that step velocity asymmetry is the primary target function in split-belt treadmill adaptation.

{"title":"Step velocity asymmetry rather than step length asymmetry is updated in split-belt treadmill adaptation","authors":"Yuki Ishida , Hikaru Yokoyama , Naotsugu Kaneko , Tatsuya Kato , Kei-ichi Ishikawa , Kimikata Nakazawa , Ken Takiyama","doi":"10.1016/j.jbiomech.2025.112564","DOIUrl":"10.1016/j.jbiomech.2025.112564","url":null,"abstract":"<div><div>When discrepancies between planned and actual movements arise due to environmental changes, humans adjust movement parameters to achieve task goals. While motor adaptation has been extensively studied, the mechanisms involved in redundant movement parameters remain unclear. Split-belt treadmill adaptation, where each belt moves at a different speed, is an example of this phenomenon. Such adaptation initially induces gait asymmetry, which diminishes over time. Previous studies have postulated step length asymmetry as the target function; however, recent evidence challenges this assumption, leaving the target function undefined. This study investigates the target function by analyzing step parameter asymmetry using the goal-equivalent manifold and generalization predictability. The goal-equivalent manifold assesses whether adaptation is close to optimal in minimizing step parameter asymmetry, while generalization predictability reflects adaptation effects across different contexts, indicating potential target functions. We propose that step velocity asymmetry, rather than step length asymmetry, serves as the target function in split-belt treadmill adaptation. This framework facilitates the prediction and interpretation of both the learning process and the transfer of learning effects from trained to untrained conditions. In addition, it explains the overadaptation of step length asymmetry and the achievement of energy-efficient gait after adaptation. Therefore, we propose that step velocity asymmetry is the primary target function in split-belt treadmill adaptation.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"182 ","pages":"Article 112564"},"PeriodicalIF":2.4,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422101","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

Estimating temporal bone-implant stresses in patients with bone-anchored lower limbs

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-06 DOI: 10.1016/j.jbiomech.2025.112569

Jake P. Tinsley , R. Dana Carpenter , Nicholas W. Vandenberg , Jason W. Stoneback , Brecca M.M. Gaffney

Bone-anchored limbs (BALs) are a transformative alternative for patients with lower-limb amputation who suffer from debilitating socket problems by eliminating the need for skin-to-prosthetic contact. Despite its successes, some individuals continue to face challenges with BALs, experiencing a loss of implant integration resulting in prosthetic loosening. A thorough understanding of biomechanical behavior at the residual limb and bone-implant interface is necessary to fully understand mechanical failure mechanisms. In addition, a deeper understanding of BAL biomechanical behavior would allow clinicians and researchers to predict and test different implant geometries, inform patient eligibility, rehabilitation strategies, and implantation methods in a safe and low-cost way. Thus, this study designed an innovative simulation method to quantify the temporal mechanical behavior of the residual limb in transfemoral and transtibial BALs by using subject-specific kinematics, musculoskeletal loads, and bone geometry and health. Our novel method was applied to two patients (one transtibial, one transfemoral) with similar BMI and age during level ground walking. Our results demonstrated a pattern of higher residual limb stresses in the transtibial model (26.80 MPa vs. 23.69 MPa). This study not only furthers our understanding of BAL biomechanics but introduces a versatile subject-specific methodology with direct applications in clinical practice. As we navigate the complexities of BAL implantation, this modeling platform lays the groundwork for more informed decision-making.

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引用次数: 0

The effects of markerless inconsistencies are at least as large as the effects of the marker-based soft tissue artefact

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-05 DOI: 10.1016/j.jbiomech.2025.112566

S. Bousigues , A. Naaim , T. Robert , A. Muller , R. Dumas

The soft tissue artefact is a well-known issue for marker-based motion analysis and markerless motion analysis is by definition free from this artefact. The goal of this study is to compare the limb skeletal inconsistencies generated by the neural networks in markerless motion capture and generated by the soft tissue artefact in marker-based motion capture using retrospective data.

Sixteen volunteers were included and were asked to perform four motor tasks (walk, sit-to-stand, stand-to-sit, countermovement jump) acquired with ten optoelectronic cameras and ten video cameras. Keypoint identification was performed in videos using Openpose. Triangulation and data augmentation algorithms were used to get an extension of anatomical landmarks. Then, lower limb skeletal inconsistencies (length variations and apparent joint dislocations) for both marker-based and markerless data were analyzed.

The length variation of the lower limbs was generally larger with markerless data (triangulated keypoints and augmented anatomical landmarks) as found with marker-based data. Mean dislocations were found smaller for the markerless data than for the marker-based data for the hip only.

The effect of the markerless inconsistencies are at least as large as the effect of the soft tissue artefact except for the hip dislocation, probably due to the soft tissue artefact that is main at the pelvis level. These inconsistencies are related to different phenomena than skin sliding as there are no correlation with joint flexion–extension angles. Thus, compensation methods proposed for soft tissue artefact are not all applicable.

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引用次数: 0

Mechanical modeling of the dynamic response of the knee joint angle in the evaluation of muscle nerve response and energy consumption

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2025-02-05 DOI: 10.1016/j.jbiomech.2025.112565

Hongyan Liu , Bailu Zhao , Qi Wang , Junghee Lee , Lei Liu , Peilong Xu , Jongchul Park

Knee joint has large loads and pressures during human movement, and understanding knee joint’s dynamic response during movement is crucial to the study of movement mechanisms and the design of effective rehabilitation programs. In order to improve the accuracy of the mechanical model in the assessment of musculo-neural response and energy consumption in the knee joint movement mechanism, the study tries to calculate the values of mass, stiffness and damping based on the ‘mass-stiffness-damping’ model combined with the Vicon system and Moxy sensors, and further analyse the musculo-neural response and energy consumption based on the measurement of the joint angle and the joint torque. The muscle nerve response and energy consumption were further analyzed. After experimental analysis, these results show that the average fitting accuracy of the knee motion at different heights reaches more than 96.5%; in comparison of the sensitivity of the knee muscle nerve response, the research model is better than the other models in terms of the stability of the response; and the change of the knee angle and angular velocity at different walking speeds leads to different degrees of energy dissipation. In summary, the mechanical model based on the “mass-stiffness-damping” model combined with the application of motion capture system and muscle oxygenation monitoring equipment provides an important method and tool for the study of knee joint angle’s dynamic response, the muscle nerve response and the evaluation of energy consumption.

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引用次数: 0