Research Progress on Vascular Mechanobiology in 2023 / 医用生物力学

The cardiovascular system is a mechanical system with the heart as the center and blood vessels as the network.Mechanical forces play a direct and key role in regulating the physiological state and pathological process of the cardiovascular system.Cardiovascular diseases such as coronary heart disease,hypertension and stroke have similar pathological basis,that is,vascular remodeling caused by vascular dysfunction and abnormal damage.Therefore,investigating how mechanical forces produce biological effects that lead to vascular remodeling,and elucidating cardiovascular mechanical signal transduction pathways and mechanical regulation pathways are of great research significance for in-depth understanding of the nature of cardiovascular disease occurrence.In this review,different mechanical forces and key mechanical response molecules are used as clues,and the latest research progress of vascular mechanobiology in 2023 is summarized.These results provide new ideas for further exploring the role of mechanical factors in the pathogenesis of cardiovascular diseases,and providing markers and potential targets for early diagnosis of the disease.

Clinical study of optimal positive end-expiratory pressure titration guided by lung stretch index in patients with acute respiratory distress syndrome / 中华危重病急救医学

Objective:To investigate the clinical practicability of positive end-expiratory pressure (PEEP) titrated by lung stretch index (SI) in patients with acute respiratory distress syndrome (ARDS).Methods:A parallel randomized controlled trial was conducted. Patients with moderate to severe ARDS who required mechanical ventilation admitted to the department of critical care medicine of General Hospital of the Yangtze River Shipping from August 2022 to February 2023 were enrolled. They were randomly divide into SI guided PEEP titration group (SI group) and pressure-volume curve (P-V curve) inspiratory low inflection point (LIP) guided PEEP titration group (LIP group). All patients were ventilated in a supine position after admission, with the head of the bed raised by 30°. The primary disease was actively treated, prone position ventilation for 12 h/d, and lung protective ventilation strategies such as controlled lung expansion were used for lung recruitment. On this basis, mechanical ventilation parameters were titrated with SI in the SI group; the LIP group titrated mechanical ventilation parameters with P-V curve inspiratory LIP+2 cmH 2O (1 cmH 2O ≈ 0.098 kPa). The oxygenation index (PaO 2/FiO 2), and respiratory mechanics indicators such as lung dynamic compliance (Cdyn), peak airway pressure (Pip) were monitored before recruitment maneuver and after 1, 3, and 5 days of treatment. The therapeutic effect of the two groups was compared. Results:There were 41 patients in the SI group and 40 patients in the LIP group. There was no significant difference in general information such as gender, age, and disease type between the two groups. The mechanical ventilation time and the length of intensive care unit (ICU) stay in the SI group were significantly shorter than those in the LIP group (days: 9.47±3.36 vs. 14.68±5.52, 22.27±4.68 vs. 27.57±9.52, both P < 0.05). Although the 28-day mortality of the SI group was lower than that of the LIP group, the difference was not statistically significant [19.5% (8/41) vs. 35.0% (14/40), P > 0.05]. On the fifth day, the PaO 2/FiO 2 was higher in SI group [mmHg (1 mmHg≈0.133 kPa): 225.57±47.85 vs. 198.32±31.59, P < 0.05], the Cdyn was higher in SI group (mL/cmH 2O: 47.39±6.71 vs. 35.88±5.35, P < 0.01), the Pip was lower in SI group (mmHg: 35.85±5.77 vs. 43.87±6.68, P < 0.05). The Kaplan-Meier survival curve showed no statistically significant difference in the 28 days cumulative survival rate between the two groups (Log-Rank: χ2 = 2.348, P = 0.125). Conclusion:The application of SI titration with PEEP in the treatment of ARDS patients may improve their prognosis.

History and national survey on reflex hammers: which is the chosen one of Brazilian neurologists? / História e questionário nacional sobre martelos de reflexo: qual é o escolhido dos neurologistas brasileiros?

Abstract Background Percussion is an important part of the neurological examination and reflex hammers are necessary to obtain it properly. Objective We aimed to review the historical aspects of the main reflex hammers and to define the favorite one of Brazilian neurologists. Methods We searched original and review articles about historical aspects of the reflex hammers in Scielo and Pubmed and conducted an online survey to investigate the favorite reflex hammer of Brazilian neurologists. Results In the first part, we describe the major milestones in the creation of the reflex hammers. Following, we exhibit the results of the online survey: Babinski-Rabiner was the most voted. Conclusions The origins of the reflex hammers goes back long before their creation, from a basic clinical examination method: percussion. Since the description of deep tendon reflexes and the creation of percussion hammers, much has been improved in this technique. Among all the hammers surveyed, the Babinski-Rabiner was the chosen one by a significant portion of Brazilian neurologists.

Resumo Antecedentes A percussão é uma parte importante do exame neurológico e os martelos de reflexo são necessários para obtê-la adequadamente. Objetivo Nós visamos revisar os aspectos históricos dos principais martelos de reflexo neurológico e definir qual é o preferido dos neurologistas brasileiros. Métodos Procuramos artigos originais e artigos de revisão sobre os aspectos históricos dos martelos de reflexo na Scielo e no Pubmed, e conduzimos um questionário online para investigar qual é o preferido dos neurologistas brasileiros. Resultados Na primeira parte, descrevemos os principais marcos na criação dos martelos de reflexo. Na sequência, expomos os resultados do questionário online: Babinski-Rabiner foi o martelo mais votado. Conclusões A origem dos martelos de reflexos vem muito antes de sua criação, a partir de um método de exame clínico básico: a percussão. Desde a descrição dos reflexos tendinosos profundos e da criação de martelos de percussão, muito se aperfeiçoou sobre essa técnica. Dentre todos os martelos pesquisados, o de Babinski-Rabiner foi o escolhido por uma parcela significativa dos neurologistas brasileiros.

Pathologically Elevated-Cyclic Stretch Suppressed Vascular Smooth Muscle Cell Mitochondrial Biogenesis by Down-regulating PGC1α Expression / 医用生物力学

Objective To investigate the effect of pathologically elevated-cyclic stretch induced by hypertension on mitochondrial biogenesis of vascular smooth muscle cells (VSMCs), and the role of PGC1α in this process. Methods The Flexcell-5000T stretch loading system in vitro was applied to VSMCs with a frequency of 1. 25 Hz and an amplitude of 5% or 15% to simulate the mechanical environment under normal physiological or hypertensive pathological conditions respectively. Western blotting and qPCR were used to detect the expression of PGC1α, citrate synthase and mitochondrial DNA (mtDNA) copy number in VSMCs under normal physiological or hypertensive pathological conditions. VSMCs were treated with PGC1α specific activator ZLN005 to promote PGC1α expression or specific interfering fragment siRNA to inhibit PGC1α expression in order to detect the effect on citrate synthase and mtDNA copy number. Results Compared with 5% physiological cyclic stretch, 15% pathologically elevated-cyclic stretch significantly suppressed the expression of PGC1α, citrate synthase and mtDNA copy number in VSMCs. Compared with control group, the protein expression of PGC1α was significantly decreased and increased respectively. When VSMCs transfected with PGC1α siRNA or incubated PGC1α activator ZLN005, the expression of citrate synthase and mtDNA copy number were also significantly down regulated and up-regulated in VSMCs accordingly. Under physiological cyclic stretch conditions, the protein level of PGC1α was significantly down-regulated by PGC1α siRNA, which also significantly down-regulated citrate synthase expression and mtDNA copy number. The protein expression of PGC1α was significantly up-regulated by ZLN005, which also enhanced the expression of citrate synthase and mtDNA copy number. Conclusions The pathological cyclic stretch induced by hypertension significantly down-regulated the expression of citrate synthase and mtDNA copy number via suppressing the expression of PGC1α, resulting in mitochondrial dysfunction of VSMCs. PGC1α may be a potential therapeutic target molecule to alleviate the progression of hypertension.

Biomechanical properties of epithelial mesenchymal transition in idiopathic pulmonary fibrosis / 生物医学工程学杂志

Idiopathic pulmonary fibrosis (IPF) is a progressive scar-forming disease with a high mortality rate that has received widespread attention. Epithelial mesenchymal transition (EMT) is an important part of the pulmonary fibrosis process, and changes in the biomechanical properties of lung tissue have an important impact on it. In this paper, we summarize the changes in the biomechanical microenvironment of lung tissue in IPF-EMT in recent years, and provide a systematic review on the effects of alterations in the mechanical microenvironment in pulmonary fibrosis on the process of EMT, the effects of mechanical factors on the behavior of alveolar epithelial cells in EMT and the biomechanical signaling in EMT, in order to provide new references for the research on the prevention and treatment of IPF.

Rehabilitation effect of Baduanjin exercises combined with stretch training with band for elderly patients with sarcopen / 国际中医中药杂志

Objective:To observe the rehabilitation effect of Baduanjin combined with elastic band training on elderly patients with sarcopenia. Methods:From January 2019 to January 2021, 120 elderly sarcopenia patients in our hospital who met the inclusion criteria were divided into two groups according to the random number table method, with 60 in each group. The control group was given conventional treatment intervention for sarcopenia, and the observation group was Baduanjin exercises combined with elastic band training on the basis of the control group. Both groups were intervened for 12 weeks. The skeletal muscle index (SMI), muscle grip strength, short physical performance battery (SPPB) and Modified Barthel Index (MBI) were used to compare between two groups before and after the intervention. Results:After treatment, the SMI index [(6.77 ± 1.03) kg/m 2vs. (6.35 ± 1.12) kg/m 2, t=2.14], muscle grip strength [(23.06 ± 3.48) kg vs. (19.41 ± 3.79) kg, t=5.50], SPPB score [(9.12 ± 2.24) vs. (7.85 ± 2.13), t=3.18] and MBI score [(82.43 ± 20.75) vs. (64.36 ± 19.42), t=4.93] of the observation group were significantly higher than those in the control group ( P<0.05). After treatment, the distribution of muscle activity function in the observation group was significantly better than that of the control group ( Z=-2.28, P=0.023). Conclusion:Baduanjin combined with elastic band training can improve the muscle function and quality of daily activities in elderly patients with sarcopenia.

Cyclic Stretch Promotes Migration of MC3T3-E1 Cells via Increasing Runx2 Expression / 医用生物力学

Objective To investigate the effects of cyclic stretch on migration of MC3T3-E1 cells and its related mechanism. Methods The strain loading system was used to stretch MC3T3-E1 cells cultured in vitro with 15% amplitude, to simulate the mechanical condition in vivo. The wound healing assay was used to detect the migration of MC3T3-E1 cells. Western blotting was used to test Runx2 expression. RNA interfering was used to decrease Runx2 expression. Results Cyclic mechanical stretch with 15% amplitude, 1.25 Hz frequency and lasting for 24 hours could promote the migration of MC3T3-E1 cells and increase the expression level of Runx2. Runx2 interference inhibited the migration of MC3T3-E1 cells in static culture condition. Interference with Runx2 expression in MC3T3-E1 cells could partially reduce the positive effect of cyclic mechanical stretch on cell migration. Conclusions Cyclic stretch can promote the migration of MC3T3-E1 cells, and Runx2 may play an important role in this process. This study provides experimental basis for finding innovative clinical treatment method to promote fracture healing.

Physiological Cyclic Stretch Inhibits Vascular Smooth Muscle Cell Migration via Activating AMPK Phosphorylation / 医用生物力学

Objective To explore the role of adenosine monophosphate-activated protein kinase (AMPK), a key regulator of cellular energy metabolism, in vascular smooth muscle cell (VSMC) migration in response to physiological cyclic stretch. Methods The Flexcell-5000T mechanical loading system was applied with a physiological cyclic stretch at 10% amplitude and 1.25 Hz frequency to primary rat VSMCs, to simulate mechanical stimulation of VSMCs in vivo. The protein expression of p-AMPK in VSMCs was detected by Western blotting, and VSMC migration was detected by wound healing test. Results Compared with the static group, physiological cyclic stretch loading for 24 h significantly decreased the area of wound healing, indicating that physiological cyclic stretch inhibited VSMC migration. The protein expression of p-AMPK in VSMCs was increased significantly after physiological cyclic stretch loading for 3 h, and was decreased significantly after 24 h. Under physiological cyclic stretch loading conditions, incubating AMPK inhibitor could significantly reduce the protein expression of p-AMPK after 3 h, and promote VSMC migration after 24 h; incubating AMPK activator AICAR under static conditions significantly increased the protein expression of p-AMPK after 3 h, and weakened VSMC migration after 24 h. Conclusions Physiological cyclic stretch inhibits VSMC migration by increasing the protein expression of p-AMPK, indicating that VSMC migration regulated by physiological cyclic stretch is of great significance for maintaining vascular homeostasis.

Src/RUNX2 Modulates the Migration of Vascular Smooth Muscle Cells Induced by Cyclic Stretch / 医用生物力学

Objective To investigate the effect of cyclic stretch on Src and Runt-related transcription factor 2 (RUNX2), and their pivotal roles in migration of vascular smooth muscle cells (VSMCs). Methods The 5% cyclic stretch (to simulate normotensive physiological condition) or 15% cyclic stretch (to simulate hypertensive pathological condition) was applied to VSMCs by FX-5000T system. Western blotting was used to detect the expression of RUNX2 and phosphorylation of Src in VSMCs. The Ingenuity Pathway Analysis (IPA) bioinformatic software was used to analyze the potential regulatory effect of Src on RUNX2. Small interfering RNA (siRNA) was transfected to decrease the expression of RUNX2. Src inhibitor-1 was used to repress Src kinase activity; Wound-healing assay was applied to detect VSMC migration. Results Compared with 5% cyclic stretch, 15% cyclic stretch significantly increased RUNX2 expression in VSMCs. Under both static and 15% cyclic stretch conditions, VSMC migration was significantly inhibited after reducing RUNX2 expression with siRNA transfection. IPA indicated that Src kinase might be the upstream modulator of RUNX2, and Western blotting validated that RUNX2 expression was significantly decreased after inhibiting Src. Furthermore, under 15% cyclic stretch, Src inhibitor-1 markedly repressed RUNX2 expression and VSMC migration.Conclusions High cyclic stretch increased phosphorylation of Src kinase and expression of RUNX2, which subsequently induced VSMC abnormal migration. Exploring the mechanobiological mechanism of VSMC migration regulated by cyclic stretch may contribute to further revealing the mechanism of vascular physiological homeostasis and vascular pathological remodeling, as well as providing new perspective for the translational research of vascular remodeling upon hypertension.

Influência da micropuntura associada à micropigmentação no tratamento de estrias albas / Influence of micropuncture associated with micropigmentation on treatment of stretch marks

Introdução: Estrias são alterações no tecido tegumentar, principalmente nas fibras de elastina e colágeno. São frequentemente acompanhadas de problemas psicossociais e de autoestima. Existem diversas técnicas utilizadas, como o microagulhamento, que estimula a produção de colágeno e a dermopigmentação, que camufla as estrias por meio da pigmentação. Objetivo: Verificar a influência do microagulhamento associado a micropigmentação em estrias albas de mulheres. Métodos: Realizou-se um protocolo de Estriaderme em três mulheres de fototipo de pele II a V, de idade média de 27 ± 0,3 anos com estrias albas nos glúteos. O protocolo foi composto por 5 sessões com intervalos quinzenais, em quatro foram realizadas a micropuntura associada ao ácido hialurônico e em uma realizou-se a micropigmentação. As participantes foram avaliadas por fotografias e paquímetro. Resultados: No pós-tratamento, observou-se uma melhora estética nas regiões de aplicação, o tecido tegumentar demonstrou-se mais uniforme, homogêneo e com maior jovialidade. Com redução na espessura das estrias e uma média de redução de 1,8 mm em relação ao pré-tratamento (média ± 3 mm). Conclusão: O protocolo Estriaderme demonstrou ter efeito positivo sobre a pele estriada, no que se refere a sua vascularização, vitalidade, pigmentação, relevo cutâneo, espessura e quantidade. (AU)

Introduction: Stretch marks are alterations in the integumentary tissue, mainly in the elastin and collagen fibers. They are often accompanied by psychosocial and selfesteem problems. Several techniques are used, such as micro-needling, which stimulates collagen production and dermopigmentation, which camouflages stretch marks by pigmenting the area. Objective: To verify the influence of micropuncture associated with micropigmentation on female striae alba. Methods: A Striaderm protocol was performed on three women of skin phototype II to V according to Fitzpatrick, mean age 27 ± 0.3 years with gluteus alba striae. The protocol consisted of 5 sessions at biweekly intervals, four underwent micropuncture associated with hyaluronic acid and one underwent micropigmentation. The participants were evaluated by photographs and caliper. Results: Post-treatment showed an aesthetic improvement in the application regions, the integumentary tissue was more uniform, homogeneous, and more youthful. With reduction in stretch marks and an average reduction of 1.8 mm compared to pretreatment (mean ± 3 mm). Conclusion: The Striaderme protocol has been shown to have a positive effect on striated skin with respect to its vascularity, vitality, pigmentation, skin relief, thickness, and quantity. (AU)

Calcium Participates in Migration of VSMCS Synergistically Induced by Cyclic Stretch and Platelet-Derived Microvesicles / 医用生物力学

Objective To investigate the synergistic effects of pathologically elevated cyclic stretch and platelet-derived microvesicles (PMVs) on migration of vascular smooth muscle cells (VSMCs) and the potential role of calcium in this process. Methods The FX-5000T strain loading system was used to apply cyclic stretch to VSMCs with magnitudes of 5% and 15%, which simulated physiological and hypertensive situation respectively in vitro; wound healing assay was used to analyze VSMCs migration; Ca2+-free medium was used to remove extracellular calcium; 2-APB (an antagonist of IP3R) was used to inhibit the release of intercellular stored calcium; GSK219 (an antagonist of TRPV4) and Nifedipine (an inhibitor of L-type voltage-gated calcium channel) were applied to block the activity of respective calcium channel; thrombin was used to stimulate platelets in vitro which simulated the hypertensive activation of PMVs in vivo. ResultsCompared with 5% cyclic stretch, 15% cyclic stretch significantly promoted VSMC migration. Removal of extracellular calcium inhibited VSMCs migration, but the application of GSK219 and Nifedipine did not affect the migration up-regulated by 15% cyclic stretch; while 2-APB which inhibited the release of intracellular stored calcium could also repress VSMCs migration under 15% cyclic stretch. PMVs further promoted VSMC migration under 15% cyclic stretch condition, and both extracellular calcium and intercellular stored calcium were involved in this process. Conclusions Both intracellular and extracellular calcium play important roles in VSMC migration induced by 15% cyclic stretch, and PMVs synergistically participate in the above process. The study is aimed to provide new mechanobiological insights into the molecular mechanism and clinical targets of vascular remodeling in hypertension.

Reliability and sensitivity of countermovement jump-derived variables in detecting different fatigue levels / Reprodutibilidade e sensibilidade das variáveis derivadas do salto com contra movimento na detecção de diferentes níveis de fadiga

ABSTRACT The aim was to verify the reliability and sensitivity of countermovement jump (CMJ) derived variables in detecting small, moderate and large changes and whether the capacity of CMJ-derived variables in detecting fatigue is dependent of the volume of the fatiguing exercise. Seventeen physically active men performed two fatigue protocols, on separate weeks, composed by continuous vertical jumps: short protocol (7 x 10 jumps) and long protocol (14 x 10 jumps). Jump height (JH), power output (PO), impulse (IMP) and vertical stiffness (KVERT) were measured during CMJ prior to and immediately after the fatigue protocols. Intraclass coefficient correlation, typical error, smallest worthwhile change and magnitude-based inference were analyzed. PO and JH presented excellent reliability and good sensitivity to detect small and medium changes, respectively. Negative effects of fatigue could be detected most likely by PO, regardless of fatiguing exercise volume. JH and IMP seem to be affected only after long protocol and KVERT only after short protocol. In conclusion, PO (peak and mean) is the better marker in CMJ with excellent reliability and sensibility, which allows detect even the small effects and differentiate the fatigue levels.

RESUMO O objetivo foi verificar a reprodutibilidade e a sensibilidade de variáveis derivadas do salto com contra movimento (CMJ) na detecção de pequenas, moderadas e grandes alterações e se a capacidade das variáveis em detectar fadiga é dependente do volume do exercício fatigante. Dezessete homens fisicamente ativos realizaram dois protocolos de fadiga, em semanas separadas, compostos por saltos verticais contínuos: protocolo curto (7 x 10 saltos) e protocolo longo (14 x 10 saltos). A altura do salto (JH), a potência (PO), o impulso (IMP) e a rigidez vertical (KVERT) foram mensurados durante o CMJ antes e imediatamente após os protocolos de fadiga. Foram avaliados o coeficiente de correlação intraclasse, erro típico de medida, mínima mudança valiosa e magnitude baseada em inferência. PO e JH apresentaram excelente reprodutibilidade e boa sensibilidade para detectar pequenas e médias alterações, respectivamente. Os efeitos da fadiga podem ser detectados mais provavelmente pela PO, independentemente do volume de exercício fatigante. JH e IMP parecem ser afetados somente após protocolo longo e KVERT somente após protocolo curto. Em conclusão, PO (pico e média) é o um marcador melhor durante o CMJ com excelente reprodutibilidade e sensibilidade, o que permite detectar até mesmo pequenos efeitos e diferenciar níveis de fadiga.

Flexibilidad de miembros inferiores y fuerza abdominal en futbolistas juveniles mediante aplicación del método pilates

Objetivo. Comparar el efecto del método Pilates con un método tradicional sobre la fuerza resistencia abdominal y la flexibilidad de los miembros inferiores en futbolistas de categoría juvenil en Cali. Metodología. La investigación se abordó desde el enfoque empírico-analítico con un diseño cuasi experimental. Para ello, se realizó pretest- intervención y postest en dos grupos, un grupo experimental y un grupo control con 40 futbolistas de la categoría juvenil de dos escuelas de fútbol de Cali, Colombia, que cumplieron con los criterios de inclusión. Resultados. Se encontraron diferencias estadísticamente significativas con el método Pilates al momento de valorar la flexibilidad de los deportistas, en la articulación de tobillo derecho en dorsiflexion (p- 0,00), en las articulaciones de las rodillas derecha e izquierda en flexión (p= 0,00), en las articulaciones de caderas derecha e izquierda para extensión y flexión (p= 0,00), en la articulaciones del tronco en flexión y extensión (p= 0,00; p- 0,02), al igual que flexión lateral derecha e izquierda (p= 0,01) y en fuerza abdominal (p= 0,00). Discusión y conclusiones. Si bien la utilización del método tradicional refleja un aumento en las medias de las variables estudiadas, dicho aumento no es estadísticamente significativo. Por el contrario, con la utilización del método Pilates como entrenamiento de la flexibilidad de miembros inferiores y fuerza muscular (abdominal) en jóvenes futbolistas se demuestra un importante aumento en las medias, evidenciando diferencias estadísticamente significativas.

Objective. To compare the effect of the Pilates method with a traditional method on abdominal resistance strength and lower limb flexibility in young soccer players from Cali. Materials and methods. The research was conducted from the empirical-analytical approach with a quasi-experimental design. For this, pre-test, intervention, and post-test were carried out in two groups, experimental and control, with 40 youth category soccer players from two soccer schools in Cali (Colombia) who met the inclusion criteria. Results: Statistically significant differences were found with the Pilates method when assessing the flexibility of the athletes in the right ankle joint in dorsiflexion (p = 0.00), the right and left knee joint in flexion (p = 0.00), the right and left hip joint in extension and flexion (p = 0.00), the trunk joint in flexion and extension (p = 0.00; p = 0.02), right and left lateral flexion (p = 0.01), and abdominal strength (p = 0.00). Discussion and Conclusions: While the traditional method reflects an increase in the means of the variables studied, this increase is not statistically significant. On the contrary, the Pilates method to train young soccer players' lower limb flexibility and muscular strength (abdominal) demonstrated a significant increase in means, with statistically significant differences.

Plyometric training improves swimming performance in recreationally-trained swimmers / O treinamento pliométrico melhora o desempenho de nadadores recreativos / El entrenamiento pliométrico mejora el desempeño de nadadores recreativos

ABSTRACT Introduction: Plyometric training significantly improves strength performance, including in aquatic sports. Objective: To compare changes in thigh girth, hamstring flexibility, squat jump height, and 200m swimming trial time induced by plyometric training in recreationally-trained swimmers. Methods: Eighteen recreationally-trained male swimmers (age=18-20 years) were randomly divided into a plyometric training group (PTG) and a control group (CG). All the swimmers completed a six-week speed swimming training plan. In the PTG only, the last ~15 min of each session was replaced with plyometric exercises. The physical characteristics and the thigh girth were measured before and after the six weeks of training. In addition, sit-and-reach flexibility and squat jump tests were conducted, as well as a 200m swimming trial. Results: Two-way ANOVA with post-hoc analysis revealed an increase in sit-and-reach flexibility (PRE: 4.5±5.3 cm; POST: 10.9±5.9 cm, p<0.01) and squat jump height (PRE: 24.9±3.7 cm; POST: 28.3±4.2 cm, p<0.01) and a decrease in 200m-swimming time (PRE: 220±26.5 sec; POST: 204±24.4 sec, p<0.01) for the PTG only. Comparing the absolute changes (post-pre) between the groups by the Student's t-test, the PTG showed a greater increase in distance reached in the sit-and-reach flexibility (PTG: 6.34±0.6 cm vs. CG: 2.4±1.2 cm, p<0.01) and squat jump height (PTG: 3.4±0.7 cm vs. CG: 0.7±0.3 cm, p<0.01) than the CG. In addition, the 200m swimming time decreased significantly more than in the CG (PTG: -15.1±2.4 sec vs. CG: -0.8±2.7 sec, p<0.01). Conclusion: Plyometric training improves jump height, flexibility, and 200m swimming performance in recreationally-trained adult swimmers. Level of Evidence II; Lesser quality RCT.

RESUMO Introdução: O treinamento pliométrico melhora significativamente o desempenho de força, inclusive em esportes aquáticos. Objetivo: Comparar alterações da circunferência da coxa, flexibilidade dos isquiotibiais, altura do salto em agachamento e tempo de prova de natação de 200 metros depois de treinamento pliométrico em nadadores recreativos. Métodos: Dezoito nadadores recreativos do sexo masculino (idade = 18 a 20 anos) foram divididos randomicamente em um grupo de treinamento pliométrico (GP) ou controle (GC). Todos realizaram um plano de treinamento de natação em velocidade por seis semanas. Somente o GP substituiu os últimos 15 minutos de cada sessão por exercícios pliométricos. As características físicas e a circunferência da coxa foram medidas antes e depois das seis semanas de treinamento. Além disso, foram testados a flexibilidade (sentar e alcançar), o salto em agachamento e a prova de natação de 200 metros. Resultados: Um teste ANOVA de duas vias com análise post hoc revelou aumento da flexibilidade (PRÉ: 4,5 ± 5,3 cm; PÓS: 10,9 ± 5,9 cm, p < 0,01) e altura do salto (PRÉ: 24,9 ± 3,7 cm; PÓS: 28,3 ± 4,2 cm, p < 0,01), assim como diminuição do tempo de natação de 200 metros (PRÉ: 220 ± 26,5 s; PÓS: 204 ± 24,4 s, p < 0,01), apenas para o GP. Ao comparar as alterações absolutas (pré-pós) entre os grupos com o teste t de Student, o GP mostrou aumento maior da distância alcançada na flexibilidade no teste sentar e alcançar (GP: 6,34 ± 0,6 cm; GC: 2,4 ± 1,2 cm, p < 0,01) e na altura do salto em agachamento (GP: 3,4±0,7 cm; GC: 0,7±0,3 cm, p <0,01) do que o GC. Além disso, o tempo de natação de 200 metros diminuiu significativamente mais do que o GC (GP: -15,1 ± 2,4 s vs. GC: -0,8±2,7 s, p <0,01). Conclusão: O treinamento pliométrico melhora a altura do salto em agachamento, a flexibilidade e o desempenho em 200 metros de natação em nadadores adultos recreativos. Nível de evidência II; ECRC de menor qualidade.

RESUMEN Introducción: El entrenamiento pliométrico mejora significativamente el desempeño de fuerza, inclusive en deportes acuáticos. Objetivo: Comparar alteraciones de la circunferencia del muslo, flexibilidad de los isquiotibiales, la altura del salto en agachamiento y tiempo de prueba de natación de 200 metros luego de entrenamiento pliométrico en nadadores recreativos. Métodos: Dieciocho nadadores recreativos del sexo masculino (edad= 18 a 20 años) fueron divididos aleatoriamente en un grupo de entrenamiento pliométrico (GP) o control (GC). Todos realizaron un plan de entrenamiento de natación en velocidad de seis semanas. Solamente el GP sustituyó los últimos 15 minutos de cada sesión con ejercicios pliométricos. Las características físicas y circunferencia de muslo se midieron antes y después de las seis semanas de entrenamiento. Además, se evaluó la flexibilidad (sentar y alcanzar), salto en agachamiento y la prueba de natación de 200 metros. Resultados: Un test ANOVA de dos vías con análisis post hoc reveló aumento de la flexibilidad (PRE: 4,5±5,3 cm; POST: 10,9±5,9 cm, p <0,01) y altura de salto (PRE: 24,9±3,7 cm; POST: 28,3±4,2 cm, p <0,01), así como disminución del tiempo de natación de 200 metros (PRE: 220±26 0,5 s POST: 204±24,4 s, p <0.01), solo para el GP. Al comparar las alteraciones absolutas (pre-post) entre los grupos con el test t de Student, el GP mostró mayor aumento de la distancia alcanzada en la flexibilidad en el test sentar y alcanzar (GP: 6,34±0,6 cm vs. GC: 2,4±1,2 cm, p <0,01) y en la altura del salto en agachamiento (GP: 3,4±0,7 cm vs. GC: 0,7±0,3 cm, p <0,01) que el GC. Además, el tiempo de natación de 200 metros disminuyó significativamente más que el GC (GP: -15,1±2,4 s vs. GC: -0,8±2,7 s, p <0,01). Conclusión: El entrenamiento pliométrico mejora la altura del salto en agachamiento, la flexibilidad y el desempeño en 200m de natación en nadadores adultos recreativos. Nivel de Evidencia II; ECRC de menor calidad.

Comparative Effect of Static Stretching and Mulligan Stretching on Hip Adductor Flexibility in Footballers - A Two Group Trial

Groin pain due to adductor strain is commonly seen in footballers. Many methods of stretching a muscle likeballistic stretching, static stretching etc are used to increase flexibility of hip adductors and prevent groinstrain. Static hip adductor stretching till now is more favored technique whereas mulligan adductor stretchingis very new and popular method of increasing muscle flexibility. The present study was undertaken to comparethe effectiveness of 2 stretching programs i.e. Mulligan adductor stretching and static stretching on tight hipadductor. In this trial, 42 athletes who fulfilled the selection criteria were selected and then divided into twogroups based on block randomization. Group-1 received Mulligan’s adductor stretching while Group-2 receivedstatic stretching of hip adductors for 3 alternative days. Hip abduction range of motion (Abd-ROM) wasmeasured on baseline, after first day treatment and finally after third day treatment by a universal goniometer.Mean difference of Abd-ROM within groups on baseline, 1st day after treatment and 3rd day after treatmentwere -8.07, -12.76, -4.69 which shows highly significant difference (p = 0.00) between 3 sessions. MeanAbd-ROM between two groups has not shown significant different (F = 2.99, p > 0.05). It is concluded thatMulligan’s adductor stretching and static stretching both are equally effective in increasing Abd-ROM

Comparative Effectiveness Of Sleeper Stretch And Cross - Body Stretch For Improving Posterior Shoulder Tightness, Pain And Function In Patients With Adhesive Capsulitis – A Randomized Controlled Trial

Background: Adhesive Capsulitis usually involves the posterior capsule tightness, which can be stretched either by sleepers or cross-body stretch techniques. The present study aimed to compare and see the effectiveness of two stretching techniques on horizontal adduction and internal rotation range of motion along with pain and disability. Methodology: The study was conducted on 30 subjects diagnosed with adhesive capsulitis (12 females and 18 males) of age group 40-65 years and meeting the inclusion as well as the exclusion criteria. Subjects were divided into three groups- Cross body stretch group (Group 1), Sleeper Stretch group (Group 2), and Control group (Group 3) randomly. Both groups 1 & 2 received the intervention given to group 3 along with the different stretching techniques three times a week for four weeks. Clinical outcome measures were horizontal adduction and internal rotation as measured with a goniometer, pain intensity on a numeric pain rating scale, and shoulder disability with the help of shoulder pain and disability index. Result: Data was collected at baseline and after four weeks of intervention in all three groups. Data were checked for normal distribution. For non-normally distributed data, Kruskal Wallis test-Pain (p-value> 0.419) and Function (p-value>0.665) and for normally distributed data, one-way repeated measure ANOVA-Shoulder Horizontal Adduction (p-value>0.284) and Internal Rotation (p-value>0.334) was used and the p-value was fixed to < 0.05. Conclusion: Both the type of stretches were equally effective for four weeks.

Research advances in pathomechanism and treatment of joint contracture / 中国骨伤

Joint contracture is one of the common musculoskeletal disorders. It has seriously disturbed patients' activities of daily living in various aspects. The pathogenesis of it is eager to explore to distinct degree. Nowadays the thickeness and fibrosis of joint capsular is redarded as the major reason to joint contracture. It is reported that excessive fibroblasts and myofibroblasts activity, collagen hyperplasia, and extracellular matrix (ECM) deposition in these fibrotic condtions lead to the contracture. In addition, upregulators of myofibroblast and collagen synthesis, transforming growth factor-beta 1 (TGF-β1), and connective tissue growth factor (CTGF) were shown to be increased. Altered levels of cytokines were also thought to play a role in this process as elevated levelsof tumor necrosis factor-α(TNF-α), matrix metalloproteinases(MMPs) and abnormal distribution tissue inhibitors of MMPs(TIMPs) were demonstrated in contracted capsules. At present, the methods for clinical treatment of joint contracture mainly include two major categories:stretching therapy, physical factor therapy, exercise therapy, botulinum toxin injection and other non-surgical treatments, arthroscopic lysis, open lysis, and other surgical treatments. Surgical treatment is performed when non-surgical treatment is difficult to achieve further improvement. It has a good effect on mild to moderate joint contracture, but it is difficult to completely restore joint activity for serious joint contracture. Although clinical treatment methods are diverse, the clinical effects are staggered and the effectiveness of their treatment is controversial. Joint contracture is an important challenge faced by orthopedics and rehabilitation physicians, therapists and patients. The review summarized the pathogenesisand treatment of joint contracture and provided a theoretical basis for clinical diagnosis and treatment.

Therapeutic application of skin stretch closure device for treatment of limbs skin wound defects in children / 中国骨伤

OBJECTIVE@#To analyze the clinical application value of adjustable skin retractor in large area of limb wound defect in children.@*METHODS@#From January 2017 to January 2019, 11 children including 9 males and 2 females, aged 4 to 12 (8.3±2.7) years old with severe lower extremity wound defects were treated with adjustable skin stretch and closure device, all of them were unilateral lower extremity large area wound defects, including 4 cases of limb skin defect caused by traffic accident, 3 cases of failure to close after osteofasciotomy and decompression, 3 cases of plate exposure after internal fixation of lower extremity fracture and 1 case of ischemic necrosis after debridement and suturing of skin avulsion. The width of the wound was (5.6±1.2) cm and the length was (7.0±1.6) cm. VSD negative pressure drainage and expanded suture were used in all the patients. Four of them had been treated with free skin graft and two had been treated with local flap transfer. The graft or flap operation failed, and the effect of the early treatment was not good.@*RESULTS@#After 5 to 14 (10.5±2.6) days of continuous traction, the wound was closed and no skin grafting or flap repair was performed. No complications such as poor blood supply, skin infection and necrosis, peripheral sensory disturbance occurred. All 11 patients were followed up for 3 to 18 (8.9±3.8) months. The wound edge skin was linear healing with slight scar.@*CONCLUSION@#It is in accordance with Wolff's law and the concept of natural tissue reconstruction to treat large-scale limb wound defects in children with adjustable skin stretch and closure device, which provides an effective method for the treatment of limb skin and soft tissue defects in children.

Berberine Inhibits Mechanical Stretch Stress induced MAPK Phosphorylation，Proliferation and Migration of Vascular Smooth Muscle Cells / 中山大学学报(医学科学版)

@#【Objective】To observe whether berberine can inhibit vascular smooth muscle cells（VSMC）proliferation induced by mechanical strength stress and to investigate the role of MAPK pathway in it.【Methods】The cultured VSMC were divided into 4 groups：negative control group（NC group），stretch stress group（SS group），berberine pretreated and stretch stress stimulation group（BBR+SS group），and berberine group. In NC group，phosphate buffer saline was used as a negative control；in SS group，stretch stress was given to VSMC；in BBR+SS group，VSMC were pretreated with berberine for 1 hour and then exposed to stretch stress；in BBR group，VSMC were treated only with berberine for 1 hour and cultured in serum- free DMEM afterwards. We collected VSMC in each group ，detected and analyzed their MAPK phosphorylation，proliferation and migration by using Western blotting，immunofluorescence and wound-healing assay respectively. 【Results】 Compare with NC group，stretch stress markedly induced VSMC proliferation and migration ，which could be inhibited significantly by berberine. Stretch stress obviously increased phosphorylation of MAPK （ERK，JNK，p38），which could be inhibited by berberine in a concentration dependent manner. 【Conclusion】 Berberine inhibits hypertension-induced proliferation and migration of VSMC through MAPK pathway. The results revealed the new use and mechanism of berberine，and provided important data for further study on the prevention and treatment of vascular remodeling caused by abnormal increase of mechanical stress in hypertension.

Effect of An-pressing manipulation on post-stroke muscle spasticity in rats and its mechanism study / 针灸推拿医学（英文版）

Objective: To explore the mechanism of An-pressing manipulation in improving post-stroke muscle spasticity, by observing the changes of γ-aminobutyric acid (GABA) and glycine (Gly) in plasma and gray matter of L1-L3 spinal cord anterior horn in post-stroke rats with muscle spasticity after An-pressing manipulation intervention. Methods: Ten of 80 adult male Sprague-Dawley (SD) rats were randomly selected as the blank group, and the remaining 70 were used for modeling. The middle cerebral artery occlusion (MCAO) rat model was established by insertion suture occlusion method in the left external carotid artery. Thirty rats with a Longa neurological score of 2-3 points and a modified Ashworth spasticity scale score of 1-, 1+, or 2 were included in the experiment. Using the random number table method, the 30 successfully modeled rats were randomly divided into a model group, an An-pressing tendon group and an An-pressing muscle belly group. Two days after modeling, rats in the An-pressing tendon group and An-pressing muscle belly group received An-pressing manipulation on the tendon and belly of quadriceps femoris muscle respectively, with the pressure of (350±50) g and the frequency of 5 s/time, 15 min per session, once a day for 5 continuous days. After the 5th treatment, the tension of the rat quadriceps femoris muscle was evaluated using the modified Ashworth spasticity scale. The Gly levels in rat plasma and L1-L3 segments of spinal cord were determined by enzyme-linked immunosorbent assay (ELISA). The GABA levels in rat plasma and L1-L3 segments of spinal cord were measured by high performance liquid chromatography (HPLC). Results: The decrease in rat muscle tension scored by the modified Ashworth spasticity scale in the An-pressing tendon group was more significant than that in the An-pressing muscle belly group (P<0.01); the increases in Gly and GABA levels in the rat plasma and L1-L3 segments of spinal cord were more significant in the An-pressing tendon group than those in the An-pressing muscle belly group (all P<0.01). Conclusion: Based on the theory of 'anti-stretch reflex' of tendon organs, the use of An-pressing manipulation to induce the 'anti-stretch reflex' by stimulating the tendon organs can improve the muscle spasticity of rats, which is better than An-pressing the muscle belly. Increased levels of Gly and GABA in rat plasma and L1-L3 segments of spinalcord may be one mechanism of An-pressing manipulation to improve muscle spasticity by stimulating tendon organs.