Purpose The primary aim of this study is to determine the prevalence of vitamin D deficiency and insufficiency among Asian athletes participating in indoor and outdoor sports in equatorial Singapore.Secondary aims are...Purpose The primary aim of this study is to determine the prevalence of vitamin D deficiency and insufficiency among Asian athletes participating in indoor and outdoor sports in equatorial Singapore.Secondary aims are to examine the relationship between vitamin D status and skeletal muscle strength and performance,and bone density.Methods Serum 25(OH)D concentrations were determined in 95 indoor and outdoor athletes across various sports.Skeletal muscle strength and performance were assessed using the isometric mid-thigh pull(IMTP),drop jump test and 30 m sprint test.Bone Mineral Density(BMD)was measured using Dual-energy X-ray Absorptiometry(DXA).Results Mean serum 25(OH)D concentrations were 28.6±8.9 ng/mL among indoor,and 39.2±13.2 ng/mL among outdoor sport athletes respectively(P<0.05).More indoor sport athletes(62%)had insufficient vitamin D compared to outdoor sport athletes(30%)(P<0.05).Outdoor sport athletes exhibited significantly greater peak force generation than indoor sport athletes(2079±470 N vs.1869±546 N,P=0.027).Other markers of muscle function were not significantly different between groups.Indoor and outdoor sport athletes did not have significantly different BMDs although none of the athletes studied presented with poor BMD.Athletes who were deficient in vitamin D had significantly lower BMD compared to athletes with sufficient vitamin D(P=0.01).Conclusion Forty-seven percent of Singaporean athletes studied had suboptimal vitamin D status.Routine monitoring of vitamin D levels among indoor sport athletes should be in place to ensure optimal health and performance.展开更多
Elbow flexion is essential to help position the hand in space and for functional use of the upper extremity.Loss of elbow function can be secondary to many etiologies,including but not limited to brachial plexus injur...Elbow flexion is essential to help position the hand in space and for functional use of the upper extremity.Loss of elbow function can be secondary to many etiologies,including but not limited to brachial plexus injury,traumatic muscle loss,oncologic treatment,poliomyelitis or congenital absence of motor function.The end result is a significant functional limitation of the upper extremity.One method to address the loss of elbow flexion is the use of a functional muscle transfer.These transfers can be performed as pedicled rotational transfers or free functional muscle transfers.This article reviews functional muscle transfers for restoration of elbow flexion as a treatment option for patients with an otherwise unreconstructable extremity.展开更多
In order to study the function of muscles of driver shoulder during vehicle steering, identification of relations between electromyograph (EMG) activity of 10 shoulder muscles and steering force was performed. The pro...In order to study the function of muscles of driver shoulder during vehicle steering, identification of relations between electromyograph (EMG) activity of 10 shoulder muscles and steering force was performed. The procedure was to perform controlled steering maneuver by right hand in a driving simulator, and based on analyzing the EMG data with steering force in the steering wheel plane, the function was identified. It was found that muscle function depends strongly on both steering rotation and steering torque directions. In clockwise steering, the long head of triceps brachii was the prime mover and an important contributor to clockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. In contrast, in counterclockwise steering, the anterior, middle and posterior deltoid, the clavicular portion of the pectoralis major and infraspinatus were the prime movers and also the important contributors to counterclockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. We conclude that the prime movers are primarily a consequence of steering direction, while the stabilizers or fixators are primarily constant. These results can be used to improve the neuromuscular model and estimate the steering comfort of driver.展开更多
Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration ...Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration arriving at the injury site results in unsatisfactory outcomes.Therefore,there is an urgent need for a treatment method that can increase the effective drug concentration in the injured area.In this study,we first fabricated a gelatin modified by methacrylic anhydride hydrogel and loaded it with vascular endothelial growth factor that allowed the controlled release of the neurotrophic factor.This modified gelatin exhibited good physical and chemical properties,biocompatibility and supported the adhesion and proliferation of RSC96 cells and human umbilical vein endothelial cells.When injected into the epineurium of crushed nerves,the composite hydrogel in the rat sciatic nerve crush injury model promoted nerve regeneration,functional recovery and vascularization.The results showed that the modified gelatin gave sustained delivery of vascular endothelial growth factors and accelerated the repair of crushed peripheral nerves.展开更多
Background: Infants with congenital muscular torticollis are born with an asymmetric range of motion and a muscular imbalance in the cervical spine, as a result of a shortening or excessive contraction of the sternocl...Background: Infants with congenital muscular torticollis are born with an asymmetric range of motion and a muscular imbalance in the cervical spine, as a result of a shortening or excessive contraction of the sternocleidomastoid muscle. Purpose: The study aimed to investigate passive range of motion (PROM) for rotation and lateral flexion, and muscle function of the cervical spine in children that had a history of CMT as infants. Study design: a prospective cohort study. Patient sample: 58 children at the age of 3.5 to 5 years that had been treated for CMT have infants participated in the study. Method: PROM was measured with protractors and muscle function was estimated with a modified Muscle Function Scale. Data from infancy were taken from earlier records. Result: PROM in rotation of the neck was mean 98.7° and PROM in lateral flexion of the neck was mean 69.1°. Symmetric PROM of the neck was found in 74% of the children for rotation and in 88% of the children for lateral flexion. Multiple regression showed that gender and PROM in rotation as infants had a significant impact on asymmetric PROM. Forty-five percent of the children had some degree of muscular imbalance in the lateral flexors of the neck. Conclusion: Possible risk factors for later asymmetric PROM are: gender, birth weight, gestation week and PROM in rotation as infants. These factors ought to be taken into consideration when developing guidelines for long-term follow-up.展开更多
A nonlinear dynamical system is proposed as a qualitative mathematical model with the twofold aim to reasonably describe the force behavior in a fatiguing sub-maximal contraction and to be possibly employed in assessi...A nonlinear dynamical system is proposed as a qualitative mathematical model with the twofold aim to reasonably describe the force behavior in a fatiguing sub-maximal contraction and to be possibly employed in assessing muscular activation indexes. The model＇s properties are studied in terms of its equilibria and their stability properties and the existence of the fatigue equilibrium is ensured as the only system＇s attractor in the feasibility range of the parameters. Suitable mathematical indicators -- related to the dynamical properties of resilience and reactivity -- are introduced to characterize the asymptotic and the transient system＇s behavior. The practical impact of the analytical results is elucidated and a connection is established between the introduced mathematical indicators and muscle functionality indexes as rate of force development, task failure time and complete restore time. Experimental validation with handgrip force signal at high load and possible practical applications are also presented.展开更多
Angiotensin （Ang）-（1-7） is recognized as a new bioactive peptide in renin-angiotensin system （RAS）. Ang-（1-7） is a counter-regulatory mediator of Ang-II which appears to be protective against cardiovascular di...Angiotensin （Ang）-（1-7） is recognized as a new bioactive peptide in renin-angiotensin system （RAS）. Ang-（1-7） is a counter-regulatory mediator of Ang-II which appears to be protective against cardiovascular disease. Recent studies have found that Ang-（1-7） played an important role in reducing smooth muscle cell proliferation and migration, improving endothelial function and regulating lipid metabolism, leading to inhibition of atherosclerotic lesions and increase of plaque stability. Although clinical application of Ang-（1-7） is restricted due to its pharmacokinetic properties, identification of stabilized compounds, including more stable analogues and specific delivery compounds, has enabled clinical application of Ang-（1-7）. In this review, we discussed recent findings concerning the biological role of Ang-（1-7） and related mechanism during atherosclerosis development. In addition, we highlighted the perspective to develop therapeutic strategies using Ang-（1-7） to treat atherosclerosis.展开更多
Aim:Quadriceps strength and knee extension,the most important factors limiting the ability to rise from a chair,are crucial for walking at an appropriate speed,ascending and descending stairs,and performing activities...Aim:Quadriceps strength and knee extension,the most important factors limiting the ability to rise from a chair,are crucial for walking at an appropriate speed,ascending and descending stairs,and performing activities such as running,dancing,and jumping.Resection of the anterior compartment of the thigh,including all four quadriceps muscles,for the treatment of a sarcoma is uncommon;however,when necessary,it is very debilitating and adversely affects a patient's quality of life without functional reconstruction.Currently,there are a limited number of complex and difficult reconstructions to restore quadriceps function that have been described with variable outcomes.We describe a simple technique that employs a single gracilis functional muscle transfer to replace essential quadriceps function.Methods:This is a case series describing the use of either a free or pedicled single gracilis muscle to restore quadriceps function following sarcoma resection.Results:Four patients underwent an anterior compartment sarcoma resection that resulted in a large segmental defect and/or denervation of all four quadriceps muscles such that no quadriceps function would remain without reconstruction.All four patients underwent a functional reconstruction using a single gracilis.Three of the living patients achieved British Medical Research Counsel Grade 4 strength,can achieve full knee extension,are able to navigate stairs,and are able to ambulate without a brace.The fourth patient unfortunately was deceased in under three months following his tumor resection.Conclusion:Despite its small size in comparison to the quadriceps muscles,with physiotherapy and training,the gracilis muscle demonstrates the capacity to hypertrophy and replace quadriceps function following limb salvage surgery.展开更多
Restoration of upper extremity function poses a unique surgical challenge.With considerations ranging from ensuring appropriate skeletal support and musculotendinous and ligamentous anatomy,restoring adequate vascular...Restoration of upper extremity function poses a unique surgical challenge.With considerations ranging from ensuring appropriate skeletal support and musculotendinous and ligamentous anatomy,restoring adequate vascularity and innervation,and providing sufficient soft tissue coverage,upper extremity injuries present a diverse range of reconstructive problems.Recent history has been marked by an expansion of novel techniques for addressing these complex issues.Sophisticated modalities,such as targeted muscle reinnervation,free functional muscle transfer,and vascularized composite allotransplantation,have become some of the most powerful tools in the armamentarium of the reconstructive surgeon.This review article aims to define the distinguishing features of each of these modalities and reviews some of their unique advantages and limitations.展开更多
The management of extremity soft tissue sarcoma is constantly evolving, and, in recent decades, limb salvage has been the main goal. More commonly, this is being achieved with a combination of neo-adjuvant radiotherap...The management of extremity soft tissue sarcoma is constantly evolving, and, in recent decades, limb salvage has been the main goal. More commonly, this is being achieved with a combination of neo-adjuvant radiotherapy,followed by wide excision and soft tissue reconstruction in the form of vascularised soft tissue transfer. Although limb salvage is now readily achievable, the resultant functional disabilities following excision of major musculotendinous and neurovascular structures can be life changing. In recent years, there has been a move towards functional limb reconstruction in the form of free functioning muscle transfer. This paper reviews the advances in functional limb reconstruction in the setting of preoperative radiation and reports our experience in this challenging reconstructive field.展开更多
文摘Purpose The primary aim of this study is to determine the prevalence of vitamin D deficiency and insufficiency among Asian athletes participating in indoor and outdoor sports in equatorial Singapore.Secondary aims are to examine the relationship between vitamin D status and skeletal muscle strength and performance,and bone density.Methods Serum 25(OH)D concentrations were determined in 95 indoor and outdoor athletes across various sports.Skeletal muscle strength and performance were assessed using the isometric mid-thigh pull(IMTP),drop jump test and 30 m sprint test.Bone Mineral Density(BMD)was measured using Dual-energy X-ray Absorptiometry(DXA).Results Mean serum 25(OH)D concentrations were 28.6±8.9 ng/mL among indoor,and 39.2±13.2 ng/mL among outdoor sport athletes respectively(P<0.05).More indoor sport athletes(62%)had insufficient vitamin D compared to outdoor sport athletes(30%)(P<0.05).Outdoor sport athletes exhibited significantly greater peak force generation than indoor sport athletes(2079±470 N vs.1869±546 N,P=0.027).Other markers of muscle function were not significantly different between groups.Indoor and outdoor sport athletes did not have significantly different BMDs although none of the athletes studied presented with poor BMD.Athletes who were deficient in vitamin D had significantly lower BMD compared to athletes with sufficient vitamin D(P=0.01).Conclusion Forty-seven percent of Singaporean athletes studied had suboptimal vitamin D status.Routine monitoring of vitamin D levels among indoor sport athletes should be in place to ensure optimal health and performance.
文摘Elbow flexion is essential to help position the hand in space and for functional use of the upper extremity.Loss of elbow function can be secondary to many etiologies,including but not limited to brachial plexus injury,traumatic muscle loss,oncologic treatment,poliomyelitis or congenital absence of motor function.The end result is a significant functional limitation of the upper extremity.One method to address the loss of elbow flexion is the use of a functional muscle transfer.These transfers can be performed as pedicled rotational transfers or free functional muscle transfers.This article reviews functional muscle transfers for restoration of elbow flexion as a treatment option for patients with an otherwise unreconstructable extremity.
基金supported by the National Natural Science Foundation of China (Grant No. 51005133)the National High Technology Research and Development Program of China (Grant No. 2011AA11A244)Special Financial Grant of the National Science Foundation for Post-doctoral Scientists of China (Grant No. 201104098)
文摘In order to study the function of muscles of driver shoulder during vehicle steering, identification of relations between electromyograph (EMG) activity of 10 shoulder muscles and steering force was performed. The procedure was to perform controlled steering maneuver by right hand in a driving simulator, and based on analyzing the EMG data with steering force in the steering wheel plane, the function was identified. It was found that muscle function depends strongly on both steering rotation and steering torque directions. In clockwise steering, the long head of triceps brachii was the prime mover and an important contributor to clockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. In contrast, in counterclockwise steering, the anterior, middle and posterior deltoid, the clavicular portion of the pectoralis major and infraspinatus were the prime movers and also the important contributors to counterclockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. We conclude that the prime movers are primarily a consequence of steering direction, while the stabilizers or fixators are primarily constant. These results can be used to improve the neuromuscular model and estimate the steering comfort of driver.
基金supported by the Interdisciplinary Program of Shanghai Jiao Tong University,China,No.YG2021QN60(both to WL)Fundamental Research Program Funding of Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,China,No.JYZZ086B(both to WL).
文摘Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration arriving at the injury site results in unsatisfactory outcomes.Therefore,there is an urgent need for a treatment method that can increase the effective drug concentration in the injured area.In this study,we first fabricated a gelatin modified by methacrylic anhydride hydrogel and loaded it with vascular endothelial growth factor that allowed the controlled release of the neurotrophic factor.This modified gelatin exhibited good physical and chemical properties,biocompatibility and supported the adhesion and proliferation of RSC96 cells and human umbilical vein endothelial cells.When injected into the epineurium of crushed nerves,the composite hydrogel in the rat sciatic nerve crush injury model promoted nerve regeneration,functional recovery and vascularization.The results showed that the modified gelatin gave sustained delivery of vascular endothelial growth factors and accelerated the repair of crushed peripheral nerves.
文摘Background: Infants with congenital muscular torticollis are born with an asymmetric range of motion and a muscular imbalance in the cervical spine, as a result of a shortening or excessive contraction of the sternocleidomastoid muscle. Purpose: The study aimed to investigate passive range of motion (PROM) for rotation and lateral flexion, and muscle function of the cervical spine in children that had a history of CMT as infants. Study design: a prospective cohort study. Patient sample: 58 children at the age of 3.5 to 5 years that had been treated for CMT have infants participated in the study. Method: PROM was measured with protractors and muscle function was estimated with a modified Muscle Function Scale. Data from infancy were taken from earlier records. Result: PROM in rotation of the neck was mean 98.7° and PROM in lateral flexion of the neck was mean 69.1°. Symmetric PROM of the neck was found in 74% of the children for rotation and in 88% of the children for lateral flexion. Multiple regression showed that gender and PROM in rotation as infants had a significant impact on asymmetric PROM. Forty-five percent of the children had some degree of muscular imbalance in the lateral flexors of the neck. Conclusion: Possible risk factors for later asymmetric PROM are: gender, birth weight, gestation week and PROM in rotation as infants. These factors ought to be taken into consideration when developing guidelines for long-term follow-up.
文摘A nonlinear dynamical system is proposed as a qualitative mathematical model with the twofold aim to reasonably describe the force behavior in a fatiguing sub-maximal contraction and to be possibly employed in assessing muscular activation indexes. The model＇s properties are studied in terms of its equilibria and their stability properties and the existence of the fatigue equilibrium is ensured as the only system＇s attractor in the feasibility range of the parameters. Suitable mathematical indicators -- related to the dynamical properties of resilience and reactivity -- are introduced to characterize the asymptotic and the transient system＇s behavior. The practical impact of the analytical results is elucidated and a connection is established between the introduced mathematical indicators and muscle functionality indexes as rate of force development, task failure time and complete restore time. Experimental validation with handgrip force signal at high load and possible practical applications are also presented.
基金This work was supported by National Natural Science Foundation of China （NSFC） （No. 81400265 and No. 81270274）, and Peking University People＇s Hospital Research and Development funds （RDB2014-16）.
文摘Angiotensin （Ang）-（1-7） is recognized as a new bioactive peptide in renin-angiotensin system （RAS）. Ang-（1-7） is a counter-regulatory mediator of Ang-II which appears to be protective against cardiovascular disease. Recent studies have found that Ang-（1-7） played an important role in reducing smooth muscle cell proliferation and migration, improving endothelial function and regulating lipid metabolism, leading to inhibition of atherosclerotic lesions and increase of plaque stability. Although clinical application of Ang-（1-7） is restricted due to its pharmacokinetic properties, identification of stabilized compounds, including more stable analogues and specific delivery compounds, has enabled clinical application of Ang-（1-7）. In this review, we discussed recent findings concerning the biological role of Ang-（1-7） and related mechanism during atherosclerosis development. In addition, we highlighted the perspective to develop therapeutic strategies using Ang-（1-7） to treat atherosclerosis.
文摘Aim:Quadriceps strength and knee extension,the most important factors limiting the ability to rise from a chair,are crucial for walking at an appropriate speed,ascending and descending stairs,and performing activities such as running,dancing,and jumping.Resection of the anterior compartment of the thigh,including all four quadriceps muscles,for the treatment of a sarcoma is uncommon;however,when necessary,it is very debilitating and adversely affects a patient's quality of life without functional reconstruction.Currently,there are a limited number of complex and difficult reconstructions to restore quadriceps function that have been described with variable outcomes.We describe a simple technique that employs a single gracilis functional muscle transfer to replace essential quadriceps function.Methods:This is a case series describing the use of either a free or pedicled single gracilis muscle to restore quadriceps function following sarcoma resection.Results:Four patients underwent an anterior compartment sarcoma resection that resulted in a large segmental defect and/or denervation of all four quadriceps muscles such that no quadriceps function would remain without reconstruction.All four patients underwent a functional reconstruction using a single gracilis.Three of the living patients achieved British Medical Research Counsel Grade 4 strength,can achieve full knee extension,are able to navigate stairs,and are able to ambulate without a brace.The fourth patient unfortunately was deceased in under three months following his tumor resection.Conclusion:Despite its small size in comparison to the quadriceps muscles,with physiotherapy and training,the gracilis muscle demonstrates the capacity to hypertrophy and replace quadriceps function following limb salvage surgery.
文摘Restoration of upper extremity function poses a unique surgical challenge.With considerations ranging from ensuring appropriate skeletal support and musculotendinous and ligamentous anatomy,restoring adequate vascularity and innervation,and providing sufficient soft tissue coverage,upper extremity injuries present a diverse range of reconstructive problems.Recent history has been marked by an expansion of novel techniques for addressing these complex issues.Sophisticated modalities,such as targeted muscle reinnervation,free functional muscle transfer,and vascularized composite allotransplantation,have become some of the most powerful tools in the armamentarium of the reconstructive surgeon.This review article aims to define the distinguishing features of each of these modalities and reviews some of their unique advantages and limitations.
文摘The management of extremity soft tissue sarcoma is constantly evolving, and, in recent decades, limb salvage has been the main goal. More commonly, this is being achieved with a combination of neo-adjuvant radiotherapy,followed by wide excision and soft tissue reconstruction in the form of vascularised soft tissue transfer. Although limb salvage is now readily achievable, the resultant functional disabilities following excision of major musculotendinous and neurovascular structures can be life changing. In recent years, there has been a move towards functional limb reconstruction in the form of free functioning muscle transfer. This paper reviews the advances in functional limb reconstruction in the setting of preoperative radiation and reports our experience in this challenging reconstructive field.
