Pub Date : 2026-01-12DOI: 10.1016/j.jbiomech.2026.113166
Hao Wu , Jiaqiu Wang , Hujin Xie , Han Yu , Zhengduo Zhu , Runxing Fang , Jianjian Zhang , Xiao Li , Huilin Zhao , Chengcheng Zhu , Zhiyong Li
Intracranial aneurysm is a life-threatening cerebrovascular disease. Recent studies have shown that irregular pulsations are associated with an increased risk of rupture. Currently, there is an urgent need for an objective and real-time method for analyzing wall deformation associated with irregular pulsations. In this study, we developed a fast and robust analytical framework based on an improved Horn-Schunck optical flow method. Verification experiments demonstrated that the proposed method exhibited sufficient accuracy and robustness. Patient-specific deformation analysis showed that irregular pulsation sites exhibited higher displacement and strain values compared with other regions of the aneurysm surface. The maximum first principal strains were significantly higher in intracranial aneurysms with irregular pulsation than in those without irregular pulsation (0.26 [0.20–0.28] vs. 0.19 [0.18–0.20], ; Wilcoxon rank-sum test). Overall, this framework can objectively identify irregular pulsations during the cardiac cycle and offers straightforward, user-friendly applicability for clinical diagnosis.
{"title":"Strain analysis of intracranial aneurysms for characterization of irregular pulsation from 4D-CT angiography","authors":"Hao Wu , Jiaqiu Wang , Hujin Xie , Han Yu , Zhengduo Zhu , Runxing Fang , Jianjian Zhang , Xiao Li , Huilin Zhao , Chengcheng Zhu , Zhiyong Li","doi":"10.1016/j.jbiomech.2026.113166","DOIUrl":"10.1016/j.jbiomech.2026.113166","url":null,"abstract":"<div><div>Intracranial aneurysm is a life-threatening cerebrovascular disease. Recent studies have shown that irregular pulsations are associated with an increased risk of rupture. Currently, there is an urgent need for an objective and real-time method for analyzing wall deformation associated with irregular pulsations. In this study, we developed a fast and robust analytical framework based on an improved Horn-Schunck optical flow method. Verification experiments demonstrated that the proposed method exhibited sufficient accuracy and robustness. Patient-specific deformation analysis showed that irregular pulsation sites exhibited higher displacement and strain values compared with other regions of the aneurysm surface. The maximum first principal strains were significantly higher in intracranial aneurysms with irregular pulsation than in those without irregular pulsation (0.26 [0.20–0.28] vs. 0.19 [0.18–0.20], <span><math><mi>p</mi><mo>=</mo><mn>0.032</mn></math></span>; Wilcoxon rank-sum test). Overall, this framework can objectively identify irregular pulsations during the cardiac cycle and offers straightforward, user-friendly applicability for clinical diagnosis.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"197 ","pages":"Article 113166"},"PeriodicalIF":2.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036970","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}
Pub Date : 2026-01-12DOI: 10.1016/j.jbiomech.2026.113163
Abu Jor , Stanley J Winser , Fan Gao , Ming Zhang , Toshiki Kobayashi
Age-related declines in sensory and musculoskeletal function contribute to impaired balance in older adults. Although foot orthoses are commonly recommended, conventional designs often fail to effectively stimulate plantar mechanoreceptor to enhance sensory feedback for postural control. This study aimed to evaluate the immediate effectiveness of 3D-printed, site-specific somatosensory stimulation foot orthoses (SSFO) with customized knob heights, compared to placebo foot orthoses (PFO) without stimulating knobs and conventional flat foot orthoses (FFO). We assessed postural balance during static standing and walking across varied treadmill slope angles. In this repeated measures design study, 23 older adults wore each orthosis type in a randomized order. Postural control and stability were quantified using center of pressure (CoP) trajectories, plantar force/pressure distributions, and subjective ratings of tactile perception and satisfaction. SSFO significantly reduced anteroposterior CoP root mean square (RMS) and range during standing with eyes open compared to both PFO and FFO. During walking, main effects of orthosis type on CoP trajectories were not significant. However, statistical parametric mapping revealed that SSFO reduced mediolateral CoP displacement and increased ground reaction forces during specific phases of uphill walking. SSFO also decreased plantar forces at toes, forefoot, and rearfoot while increasing midfoot loading under certain conditions. Subjective ratings indicated greater perceived effectiveness and safety for SSFO compared to the other orthoses. These findings highlight the potential of site-specific customized SSFO to enhance somatosensory feedback and improve postural balance in older adults. This novel orthotic approach merits further investigation into long-term effects and optimal stimulation strategies.
{"title":"Effects of 3D printed somatosensory stimulation foot orthoses with customized knob heights on postural balance and gait in older adults","authors":"Abu Jor , Stanley J Winser , Fan Gao , Ming Zhang , Toshiki Kobayashi","doi":"10.1016/j.jbiomech.2026.113163","DOIUrl":"10.1016/j.jbiomech.2026.113163","url":null,"abstract":"<div><div>Age-related declines in sensory and musculoskeletal function contribute to impaired balance in older adults. Although foot orthoses are commonly recommended, conventional designs often fail to effectively stimulate plantar mechanoreceptor to enhance sensory feedback for postural control. This study aimed to evaluate the immediate effectiveness of 3D-printed, site-specific somatosensory stimulation foot orthoses (SSFO) with customized knob heights, compared to placebo foot orthoses (PFO) without stimulating knobs and conventional flat foot orthoses (FFO). We assessed postural balance during static standing and walking across varied treadmill slope angles. In this repeated measures design study, 23 older adults wore each orthosis type in a randomized order. Postural control and stability were quantified using center of pressure (CoP) trajectories, plantar force/pressure distributions, and subjective ratings of tactile perception and satisfaction. SSFO significantly reduced anteroposterior CoP root mean square (RMS) and range during standing with eyes open compared to both PFO and FFO. During walking, main effects of orthosis type on CoP trajectories were not significant. However, statistical parametric mapping revealed that SSFO reduced mediolateral CoP displacement and increased ground reaction forces during specific phases of uphill walking. SSFO also decreased plantar forces at toes, forefoot, and rearfoot while increasing midfoot loading under certain conditions. Subjective ratings indicated greater perceived effectiveness and safety for SSFO compared to the other orthoses. These findings highlight the potential of site-specific customized SSFO to enhance somatosensory feedback and improve postural balance in older adults. This novel orthotic approach merits further investigation into long-term effects and optimal stimulation strategies.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"196 ","pages":"Article 113163"},"PeriodicalIF":2.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980382","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}
Pub Date : 2026-01-08DOI: 10.1016/j.jbiomech.2026.113157
R.R. Kurnianto , J.M. Hijmans , C. Greve , H. Houdijk
Rocker shoes are often prescribed to reduce pressure in diabetic patients with loss of protective sensation but optimal apex position (AP) and apex angle (AA) vary across individuals. This study investigated whether human-in-the-loop optimization (HILO) can offload multiple high-pressure forefoot zones simultaneously without excessively increasing pressure in low-pressure regions. Ten healthy adults with ≥ 2 forefoot zones exceeding 200 kPa were recruited. Peak plantar pressure was measured using in-shoe sensors, and forefoot zones were classified as “at risk” (AR, ≥200 kPa) or “no risk” (NR, <200 kPa). An evolutionary optimization algorithm was used to find optimal AP and AA to reduce peak pressure in all forefoot regions simultaneously. The HILO optimized shoe was compared with a generic personalization algorithm (Malki) and a control shoe. HILO and Malki shoes significantly reduced the number of AR zones compared to control (p < 0.001 and p = 0.005, respectively). While AP settings were similar (HILO = 62.1 ± 1.7 %; Malki = 63.1 ± 3.0 %), HILO resulted in a wider range of AA (96.9° ± 32.6°) compared to Malki (96.9° ± 8.9°). HILO offloaded all zones that Malki did plus four additional zones across three participants, achieving an 81 % success rate versus 65 % for Malki across participants in this study. These findings demonstrate HILO’s potential to individually optimize rocker shoe settings for multi-zone offloading. HILO could find settings that deviate from general guidelines, but deliver similar or better performance. Future work should validate HILO in patients and streamline the protocol to improve clinical feasibility.
{"title":"Human in the loop optimization of rocker shoes for offloading plantar pressure in the forefoot","authors":"R.R. Kurnianto , J.M. Hijmans , C. Greve , H. Houdijk","doi":"10.1016/j.jbiomech.2026.113157","DOIUrl":"10.1016/j.jbiomech.2026.113157","url":null,"abstract":"<div><div>Rocker shoes are often prescribed to reduce pressure in diabetic patients with loss of protective sensation but optimal apex position (AP) and apex angle (AA) vary across individuals. This study investigated whether human-in-the-loop optimization (HILO) can offload multiple high-pressure forefoot zones simultaneously without excessively increasing pressure in low-pressure regions. Ten healthy adults with ≥ 2 forefoot zones exceeding 200 kPa were recruited. Peak plantar pressure was measured using in-shoe sensors, and forefoot zones were classified as “at risk” (AR, ≥200 kPa) or “no risk” (NR, <200 kPa). An evolutionary optimization algorithm was used to find optimal AP and AA to reduce peak pressure in all forefoot regions simultaneously. The HILO optimized shoe was compared with a generic personalization algorithm (Malki) and a control shoe. HILO and Malki shoes significantly reduced the number of AR zones compared to control (p < 0.001 and p = 0.005, respectively). While AP settings were similar (HILO = 62.1 ± 1.7 %; Malki = 63.1 ± 3.0 %), HILO resulted in a wider range of AA (96.9° ± 32.6°) compared to Malki (96.9° ± 8.9°). HILO offloaded all zones that Malki did plus four additional zones across three participants, achieving an 81 % success rate versus 65 % for Malki across participants in this study. These findings demonstrate HILO’s potential to individually optimize rocker shoe settings for multi-zone offloading. HILO could find settings that deviate from general guidelines, but deliver similar or better performance. Future work should validate HILO in patients and streamline the protocol to improve clinical feasibility.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"196 ","pages":"Article 113157"},"PeriodicalIF":2.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145966051","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}
This study investigated the thickness and stiffness of the heel fat pad among male university athletes involved in sports with different performance characteristics: with shoes, barefoot, and in water. Participants included 34 male athletes—12 judo players (barefoot competition), 10 American football players (shoe competition), and 12 swimmers (water-based)—as well as 12 male non-athlete controls. Using ultrasonography, we measured the thickness of the shallow and deep layers of the heel fat pad under 0%, 50%, and 100% loading conditions, along with their respective rates of change. Stiffness (elasticity) of both layers was also assessed. At 0% load, both the shallow and deep layers were thickest in swimmers and thinner in judo and American football athletes. In the shallow layer, swimmers showed the greatest rate of change in thickness with loading. In the deep layer, significant changes were found in the judo and swimmer groups compared to the American football group, and in swimmers compared to controls. Elasticity in the shallow layer was lower in American football players than in the judo and swimmer groups. In the deep layer, judo athletes had the lowest elasticity, whereas swimmers had the highest. These findings indicate that the heel fat pad’s morphology and mechanical properties differ across sports disciplines, likely reflecting adaptations to sport-specific loading patterns.
{"title":"Functional and anatomical characteristics of the heel fat pad based on different sports events","authors":"Toshihiro Maemichi , Masatomo Matsumoto , Takumi Okunuki , Toshiharu Tsutsui , Tsukasa Kumai","doi":"10.1016/j.jbiomech.2026.113148","DOIUrl":"10.1016/j.jbiomech.2026.113148","url":null,"abstract":"<div><div>This study investigated the thickness and stiffness of the heel fat pad among male university athletes involved in sports with different performance characteristics: with shoes, barefoot, and in water. Participants included 34 male athletes—12 judo players (barefoot competition), 10 American football players (shoe competition), and 12 swimmers (water-based)—as well as 12 male non-athlete controls. Using ultrasonography, we measured the thickness of the shallow and deep layers of the heel fat pad under 0%, 50%, and 100% loading conditions, along with their respective rates of change. Stiffness (elasticity) of both layers was also assessed. At 0% load, both the shallow and deep layers were thickest in swimmers and thinner in judo and American football athletes. In the shallow layer, swimmers showed the greatest rate of change in thickness with loading. In the deep layer, significant changes were found in the judo and swimmer groups compared to the American football group, and in swimmers compared to controls. Elasticity in the shallow layer was lower in American football players than in the judo and swimmer groups. In the deep layer, judo athletes had the lowest elasticity, whereas swimmers had the highest. These findings indicate that the heel fat pad’s morphology and mechanical properties differ across sports disciplines, likely reflecting adaptations to sport-specific loading patterns.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"196 ","pages":"Article 113148"},"PeriodicalIF":2.4,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980381","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}
Pub Date : 2026-01-06DOI: 10.1016/j.jbiomech.2026.113150
Siquan Cheng , Lunxin Liu , Yue Qiu , YiKe Diao , Daiyang He , Fei Yan , ChaoHua Wang , Kang Li
Blood blister-like aneurysms (BBAs) are a rare and severe type of aneurysms with high mortality and morbidity. While BBAs are known to occur predominantly in plateau sections, their exact cause remains unclear. This study aims to investigate the correlation between oxygen mass transport and BBA initiation with patient-specific computational fluid dynamics (CFD) methods. A group of 12 BBA patients were enrolled. The mass transport of oxygen (O2), time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI) were analyzed. Results show that the O2 transport rate in the region where BBA occurs is very low in for 11 out of 12 patients. This region is also associated with low TAWSS and high OSI. In conclusion, this study strongly supports that mass transport of O2 and hemodynamics exhibit the potential to serve as a diagnostic biomarker for BBAs. Furthermore, it is important to eliminate the hypoxia region of BBA during treatment.
{"title":"Hypoxia promotes blood blister-like aneurysms development: A computational fluid dynamics study","authors":"Siquan Cheng , Lunxin Liu , Yue Qiu , YiKe Diao , Daiyang He , Fei Yan , ChaoHua Wang , Kang Li","doi":"10.1016/j.jbiomech.2026.113150","DOIUrl":"10.1016/j.jbiomech.2026.113150","url":null,"abstract":"<div><div>Blood blister-like aneurysms (BBAs) are a rare and severe type of aneurysms with high mortality and morbidity. While BBAs are known to occur predominantly in plateau sections, their exact cause remains unclear. This study aims to investigate the correlation between oxygen mass transport and BBA initiation with patient-specific computational fluid dynamics (CFD) methods. A group of 12 BBA patients were enrolled. The mass transport of oxygen (O<sub>2</sub>), time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI) were analyzed. Results show that the O<sub>2</sub> transport rate in the region where BBA occurs is very low in for 11 out of 12 patients. This region is also associated with low TAWSS and high OSI. In conclusion, this study strongly supports that mass transport of O<sub>2</sub> and hemodynamics exhibit the potential to serve as a diagnostic biomarker for BBAs. Furthermore, it is important to eliminate the hypoxia region of BBA during treatment.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"196 ","pages":"Article 113150"},"PeriodicalIF":2.4,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979737","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}
Cerebrovascular dysfunction is associated with aging and the progression of neurodegenerative diseases. Optical coherence elastography (OCE) is an emerging technique for measuring the stiffness of arteries nondestructively with high spatial resolution. In this study, we employed wave-based OCE to measure the shear modulus of human anterior cerebral arteries (ACA). Surface elastic waves were excited on ACA across a wide frequency range (2 to 100 kHz), at intra-vessel pressures ranging from 20 to 140 mmHg. Lamb wave theory was applied to analyze the propagation speeds of dispersive elastic waves guided along the arterial walls and determine shear modulus. The measured shear modulus increases linearly with pressure, reflecting the hyper-elastic properties of arterial walls. The data were compared with stiffness values derived from conventional biaxial extension-inflation mechanical testing. The shear modulus determined from high frequency OCE measurements are much higher when compared to those from the quasi-static mechanical tests. Nevertheless, both measurements demonstrated a consistent trend of cerebral artery stiffening with aging.
{"title":"Nondestructive measurement of anterior cerebral artery stiffness using optical coherence elastography","authors":"Mykyta Ananchenko , Xu Feng , Samuel Halvorsen , Seok-Hyun Yun , Yanhang Zhang","doi":"10.1016/j.jbiomech.2026.113147","DOIUrl":"10.1016/j.jbiomech.2026.113147","url":null,"abstract":"<div><div>Cerebrovascular dysfunction is associated with aging and the progression of neurodegenerative diseases. Optical coherence elastography (OCE) is an emerging technique for measuring the stiffness of arteries nondestructively with high spatial resolution. In this study, we employed wave-based OCE to measure the shear modulus of human anterior cerebral arteries (ACA). Surface elastic waves were excited on ACA across a wide frequency range (2 to 100 kHz), at intra-vessel pressures ranging from 20 to 140 mmHg. Lamb wave theory was applied to analyze the propagation speeds of dispersive elastic waves guided along the arterial walls and determine shear modulus. The measured shear modulus increases linearly with pressure, reflecting the hyper-elastic properties of arterial walls. The data were compared with stiffness values derived from conventional biaxial extension-inflation mechanical testing. The shear modulus determined from high frequency OCE measurements are much higher when compared to those from the quasi-static mechanical tests. Nevertheless, both measurements demonstrated a consistent trend of cerebral artery stiffening with aging.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"196 ","pages":"Article 113147"},"PeriodicalIF":2.4,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145966171","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}
Pub Date : 2026-01-01DOI: 10.1016/j.jbiomech.2025.113146
Tsuyoshi Nagatani , Shayne Vial , Kristina L. Kendall , Paul Comfort , G.Gregory Haff
The purpose of this study was to examine the relationship between vertical barbell acceleration patterns and power clean performance. Thirty strength-power athletes performed a one repetition maximum (1RM) power clean test, recording vertical barbell acceleration data from their heaviest successful lifts. This data was then analysed using functional principal component (fPC) analysis methods. Three vertical barbell acceleration patterns were extracted, with each primarily reflecting variations in the magnitude of vertical barbell acceleration during the second pull (fPC1), the transition (fPC2), and the first pull (fPC3). Additionally, two fPCs were extracted from displacement fields, which explain timing variations in barbell acceleration data, with the first fPC capturing timing variations during the first pull and the second fPC capturing timing variations during the transition. There were no significant or meaningful correlations between any of these patterns and power clean performance, suggesting that the amplitude and timing variations of vertical barbell acceleration patterns may not be the key biomechanical factor impacting power clean performance. Therefore, vertical barbell acceleration profiles should not be interpreted as a direct indicator of power clean technique, as these patterns may simply reflect acceptable individual variation, rather than representing technical proficiency or inefficiency. These findings may highlight that isolated measures of barbell kinematics should be considered informative, yet insufficient for assessing weightlifting technique, without additional variables reflecting the kinetics and kinematics of the lifter considered.
{"title":"Functional data analysis of vertical barbell acceleration during the pull of the power clean","authors":"Tsuyoshi Nagatani , Shayne Vial , Kristina L. Kendall , Paul Comfort , G.Gregory Haff","doi":"10.1016/j.jbiomech.2025.113146","DOIUrl":"10.1016/j.jbiomech.2025.113146","url":null,"abstract":"<div><div>The purpose of this study was to examine the relationship between vertical barbell acceleration patterns and power clean performance. Thirty strength-power athletes performed a one repetition maximum (1RM) power clean test, recording vertical barbell acceleration data from their heaviest successful lifts. This data was then analysed using functional principal component (fPC) analysis methods. Three vertical barbell acceleration patterns were extracted, with each primarily reflecting variations in the magnitude of vertical barbell acceleration during the second pull (fPC1), the transition (fPC2), and the first pull (fPC3). Additionally, two fPCs were extracted from displacement fields, which explain timing variations in barbell acceleration data, with the first fPC capturing timing variations during the first pull and the second fPC capturing timing variations during the transition. There were no significant or meaningful correlations between any of these patterns and power clean performance, suggesting that the amplitude and timing variations of vertical barbell acceleration patterns may not be the key biomechanical factor impacting power clean performance. Therefore, vertical barbell acceleration profiles should not be interpreted as a direct indicator of power clean technique, as these patterns may simply reflect acceptable individual variation, rather than representing technical proficiency or inefficiency. These findings may highlight that isolated measures of barbell kinematics should be considered informative, yet insufficient for assessing weightlifting technique, without additional variables reflecting the kinetics and kinematics of the lifter considered.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113146"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145879993","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}
Pub Date : 2026-01-01DOI: 10.1016/j.jbiomech.2025.113103
Rachel S. Reeser , Mitchell C. VeDepo , Rukshika S. Hewawasam , Katherine A. Waugh , Kyndal A. Schade , Mostafa Abdel-Hafiz , Brisa Peña , Luisa Mestroni , Orfeo Sbaizero , Joaquin M. Espinosa , Chelsea M. Magin , Jeffrey G. Jacot
Individuals with Down syndrome (DS) account for 70% of all cases of patients diagnosed with a septal heart defect.
To investigate the mechanisms underlying aberrant septation in Down syndrome, we examined how altered extracellular-matrix composition and tissue stiffness in the Dp16 mouse model influence cardiomyocyte mechanotransduction using trisomy 21 iPSC-derived cardiomyocytes, revealing a potential biomechanical pathway contributing to congenital heart defects in the Down syndrome population.
We hypothesized that in DS, upregulation of type VI collagen and hyaluronic acid in the endocardial cushion increases cushion stiffness, altering cellular mechanotransduction and ultimately leading to differences in cell proliferation and gene expression that perturb heart development. Results found that endocardial cushions of the Dp16 mouse model of DS showed a non-significant trend toward increased stiffness compared to WT. Furthermore, iPSC-CM with trisomy 21 exhibited decreased proliferation following culture on substrates of increasing stiffness, and following cyclic mechanical stretch, DS iPSC-CM developed stress fibers, disorganized sarcomeres and a decreased expression of mature cardiac markers. Yet cyclic mechanical stretch of control iPSC-CM induced sarcomere alignment and increased mature cardiac gene expression compared to static conditions. These data argue that tissue mechanics, driven by upregulation of ECM proteins, lead to increased endocardial cushion stiffness in the Dp16 mouse, and that iPSC-CM with trisomy 21 aberrantly respond to changes to stiffness and stretch, ultimately proposing a novel avenue to investigate congenital heart defects in the DS population.
{"title":"Aberrant tissue mechanics and mechanotransduction during heart development in down syndrome","authors":"Rachel S. Reeser , Mitchell C. VeDepo , Rukshika S. Hewawasam , Katherine A. Waugh , Kyndal A. Schade , Mostafa Abdel-Hafiz , Brisa Peña , Luisa Mestroni , Orfeo Sbaizero , Joaquin M. Espinosa , Chelsea M. Magin , Jeffrey G. Jacot","doi":"10.1016/j.jbiomech.2025.113103","DOIUrl":"10.1016/j.jbiomech.2025.113103","url":null,"abstract":"<div><div>Individuals with Down syndrome (DS) account for 70% of all cases of patients diagnosed with a septal heart defect.</div><div>To investigate the mechanisms underlying aberrant septation in Down syndrome, we examined how altered extracellular-matrix composition and tissue stiffness in the Dp16 mouse model influence cardiomyocyte mechanotransduction using trisomy 21 iPSC-derived cardiomyocytes, revealing a potential biomechanical pathway contributing to congenital heart defects in the Down syndrome population.</div><div>We hypothesized that in DS, upregulation of type VI collagen and hyaluronic acid in the endocardial cushion increases cushion stiffness, altering cellular mechanotransduction and ultimately leading to differences in cell proliferation and gene expression that perturb heart development. Results found that endocardial cushions of the Dp16 mouse model of DS showed a non-significant trend toward increased stiffness compared to WT. Furthermore, iPSC-CM with trisomy 21 exhibited decreased proliferation following culture on substrates of increasing stiffness, and following cyclic mechanical stretch, DS iPSC-CM developed stress fibers, disorganized sarcomeres and a decreased expression of mature cardiac markers. Yet cyclic mechanical stretch of control iPSC-CM induced sarcomere alignment and increased mature cardiac gene expression compared to static conditions. These data argue that tissue mechanics, driven by upregulation of ECM proteins, lead to increased endocardial cushion stiffness in the Dp16 mouse, and that iPSC-CM with trisomy 21 aberrantly respond to changes to stiffness and stretch, ultimately proposing a novel avenue to investigate congenital heart defects in the DS population.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113103"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145863149","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}
Pub Date : 2026-01-01DOI: 10.1016/j.jbiomech.2025.113140
Justyna Michalska, Żaneta Szuplak, Kajetan J. Słomka, Grzegorz Juras
Assessing ballroom dancers as a pair rather than as isolated subjects provides a deeper insight into postural control mechanisms. The aim of this study was to evaluate postural sway in ballroom dancers by comparing the male partner, the female partner, and the dance couple in the standard dance position. Seven international standard ballroom dance couples and fourteen amateur dancers with three months of ballroom training participated voluntarily. Postural sway was assessed using two force plates. Subjects assumed a standard dance position preceded by a short dance phase and were instructed to hold the position for 30 s. Each trial was repeated twice. Center of pressure (COP) parameters were calculated for the anterior–posterior and medio–lateral planes, and a two-way mixed-design ANOVA was applied to assess group and positional effects Significant main effects of group (professional vs. amateur dancers) were found for COP parameters in both planes, with professionals showing higher range of COP (ra COP), root mean square of COP (rms COP), and velocity of COP (v COP) values (p ≤ 0.003, η2p = 0.20–0.50).The effect of condition (male, female, pair) was also significant for most COP variables (p ≤ 0.001, η2p = 0.15–0.41), with female dancers demonstrating lower v COP and Sample entropy (SampEn) values compared to males and pairs. No significant group × position interactions were observed in the anterior–posterior plane (p ≥ 0.06), whereas a significant interaction appeared in the medio–lateral plane for SampEn (p = 0.04, η2p = 0.15). Ballroom dance training influences postural sway. The female partner appears to stabilize the couple, while professional couples exhibit less regular COP signals, suggesting greater automation of postural control compared to amateurs.
{"title":"Let’s dance −Postural control in ballroom dance Couples: Differences between Profesfsional and amateur dancers","authors":"Justyna Michalska, Żaneta Szuplak, Kajetan J. Słomka, Grzegorz Juras","doi":"10.1016/j.jbiomech.2025.113140","DOIUrl":"10.1016/j.jbiomech.2025.113140","url":null,"abstract":"<div><div>Assessing ballroom dancers as a pair rather than as isolated subjects provides a deeper insight into postural control mechanisms. The aim of this study was to evaluate postural sway in ballroom dancers by comparing the male partner, the female partner, and the dance couple in the standard dance position. Seven international standard ballroom dance couples and fourteen amateur dancers with three months of ballroom training participated voluntarily. Postural sway was assessed using two force plates. Subjects assumed a standard dance position preceded by a short dance phase and were instructed to hold the position for 30 s. Each trial was repeated twice. Center of pressure (COP) parameters were calculated for the anterior–posterior and medio–lateral planes, and a two-way mixed-design ANOVA was applied to assess group and positional effects Significant main effects of group (professional vs. amateur dancers) were found for COP parameters in both planes, with professionals showing higher range of COP (ra COP), root mean square of COP (rms COP), and velocity of COP (v COP) values (p ≤ 0.003, η<sup>2</sup>p = 0.20–0.50).The effect of condition (male, female, pair) was also significant for most COP variables (p ≤ 0.001, η<sup>2</sup>p = 0.15–0.41), with female dancers demonstrating lower v COP and Sample entropy (SampEn) values compared to males and pairs. No significant group × position interactions were observed in the anterior–posterior plane (p ≥ 0.06), whereas a significant interaction appeared in the medio–lateral plane for SampEn (p = 0.04, η<sup>2</sup>p = 0.15). Ballroom dance training influences postural sway. The female partner appears to stabilize the couple, while professional couples exhibit less regular COP signals, suggesting greater automation of postural control compared to amateurs.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113140"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145878320","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}
Pub Date : 2026-01-01DOI: 10.1016/j.jbiomech.2025.113138
Li Mengtao , Wang Yawei , Niu Luoyan , Zhang Haoran , He Dongze , Xi Renhan , Liu Jialong , Fan Yubo
The transport and deposition of drug particles within patient’s respiratory systems played a vital role in determining the therapeutic effectiveness of inhalation therapy. This study focused on transport of inhalable particles to different lung lobes and the influences of breath-holding. An in vitro simulation system including a 3D printed respiratory tract, a respiratory pattern simulator and special-designed particle collectors was built for investigating transport of drug particles to different lung zones. A corresponding computational fluid dynamics (CFD) model was also constructed. A transport ratio, ωT, and a deposition ratio, ωD, were defined for comparatively studying particles delivered to different lung lobes and deposited to different locations in the respiratory tract. In vitro experimental results revealed significant higher ωT to the left lung (29.1 % ± 4.2 %) compared to the right one (22.1 ± 4.4 %) under normal breathing condition, while ωT to the left upper (14.4 % ± 3.1 %) and left lower lobes were greater (14.6 % ± 2.8 %) than to the right lower lobe (10.5 % ± 3.0 %) than to the right middle and upper lobes (5.7 % ± 1.2 % and 6 % ± 2.0 %, respectively), and these results were in consistent to numerical simulation results. The results also showed that breath-holding increased nasal deposition ωD by 31–65 %, but had little effects on overall ωT to different lung lobes. These findings highlighted the role of airway anatomy and airflow dynamics in particles delivery, offering insights for optimizing inhalation therapy by identifying key mechanisms of aerosol transport and deposition.
{"title":"Transport and deposition of inhalable aerosol drug particles in the human respiratory tract: variations across lung zones and the impact of breath-holding","authors":"Li Mengtao , Wang Yawei , Niu Luoyan , Zhang Haoran , He Dongze , Xi Renhan , Liu Jialong , Fan Yubo","doi":"10.1016/j.jbiomech.2025.113138","DOIUrl":"10.1016/j.jbiomech.2025.113138","url":null,"abstract":"<div><div>The transport and deposition of drug particles within patient’s respiratory systems played a vital role in determining the therapeutic effectiveness of inhalation therapy. This study focused on transport of inhalable particles to different lung lobes and the influences of breath-holding. An in vitro simulation system including a 3D printed respiratory tract, a respiratory pattern simulator and special-designed particle collectors was built for investigating transport of drug particles to different lung zones. A corresponding computational fluid dynamics (CFD) model was also constructed. A transport ratio, <em>ω</em><sub>T</sub>, and a deposition ratio, <em>ω</em><sub>D</sub>, were defined for comparatively studying particles delivered to different lung lobes and deposited to different locations in the respiratory tract. In vitro experimental results revealed significant higher ωT to the left lung (29.1 % ± 4.2 %) compared to the right one (22.1 ± 4.4 %) under normal breathing condition, while ωT to the left upper (14.4 % ± 3.1 %) and left lower lobes were greater (14.6 % ± 2.8 %) than to the right lower lobe (10.5 % ± 3.0 %) than to the right middle and upper lobes (5.7 % ± 1.2 % and 6 % ± 2.0 %, respectively), and these results were in consistent to numerical simulation results. The results also showed that breath-holding increased nasal deposition <em>ω</em><sub>D</sub> by 31–65 %, but had little effects on overall <em>ω</em><sub>T</sub> to different lung lobes. These findings highlighted the role of airway anatomy and airflow dynamics in particles delivery, offering insights for optimizing inhalation therapy by identifying key mechanisms of aerosol transport and deposition.</div></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":"195 ","pages":"Article 113138"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145878342","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}
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