The application of the parallel mechanism is still limited in the humanoid robot fields, and the existing parallel humanoid robot joint has not yet been reflected the characteristics of the parallel mechanism complete...The application of the parallel mechanism is still limited in the humanoid robot fields, and the existing parallel humanoid robot joint has not yet been reflected the characteristics of the parallel mechanism completely, also failed to solve the problem, such as small workspace, effectively. From the structural and functional bionic point of view, a three degrees of freedom（DOFs） spherical parallel mechanism for the shoulder complex of the humanoid robot is presented. According to the structure and kinetic characteristics analysis of the human shoulder complex, 3-PSS/S（P for prismatic pair, S for spherical pair） is chosen as the original configuration for the shouder complex. Using genetic algorithm, the optimization of the 3-PSS/S spherical parallel mechanism is performed, and the orientation workspace of the prototype mechanism is enlarged obviously. Combining the practical structure characteristics of the human shouder complex, an offset output mode, which means the output rod of the mechanism turn to any direction at the point a certain distance from the rotation center of the mechanism, is put forward, which provide possibility for the consistent of the workspace of the mechanism and the actual motion space of the human body shoulder joint. The relationship of the attitude angles between different coordinate system is derived, which establishs the foundation for the motion descriptions under different conditions and control development. The 3-PSS/S spherical parallel mechanism is proposed for the shoulder complex, and the consistence of the workspace of the mechanism and the human shoulder complex is realized by the stuctural parameter optimization and the offset output design.展开更多
The structure design for high ratio of carrying capacity to deadweight is one of the challenges for the bionic mechanism,while the problem concerning high carrying capacity has not yet be solved for the existing shoul...The structure design for high ratio of carrying capacity to deadweight is one of the challenges for the bionic mechanism,while the problem concerning high carrying capacity has not yet be solved for the existing shoulder complex.A new type biomimetic shoulder complex,which adopts 3-PSS/S（P for prismatic pair,S for spherical pair） spherical parallel mechanism（SPM）,is proposed.The static equilibrium equations of each component are established by using the vector method and the equations for constrain forces with certain load are solved.Then the constrain force on the middle limb and that on the side limbs are compared in order to verify the unloading performance of the mechanism.In addition,the prototype mechanism of the shoulder complex is developed,and the force feedback experiment is conducted to verify the static analysis,which indicates that the middle limb suffers most of the external force and the effect of mechanics unloading is achieved.The 3-PSS/S spherical parallel mechanism is presented for the shoulder complex,and the realization of mechanics unloading is benefit for the improvement of the carrying capacity of the shoulder complex.展开更多
Posterior instability of the shoulder is a rare condition and represents about 10% of shoulder instability. It has become more frequently recognized in the last year,even though it is more difficult to diagnose than a...Posterior instability of the shoulder is a rare condition and represents about 10% of shoulder instability. It has become more frequently recognized in the last year,even though it is more difficult to diagnose than anterior shoulder instability. As this form of shoulder pathology is somewhat rare,biomechanical knowledge is limited. The purpose of our study was to perform an extensive literature search,including PubMed and Medline,and to give an overview of the current knowledge on the biomechanics of posterior shoulder instability. The Pub Med/Medline databases were utilized,and all articles related to posterior shoulder instability and biomechanics were included to form a comprehensive compilation of current knowledge. A total of 93 articles were deemed relevant according to our inclusion and exclusion criteria. As expected with any newly acknowledged pathology,biomechanical studies on posterior shoulder instability remain limited in the literature. Current biomechanical models are performed in a static manner,which limits their translation for explaining a dynamic pathology. Newer models should incorporate dynamic stabiliza-tion of both the rotator cuff and scapulothoracic joint. There is a current lack of knowledge with regards to the pathomechanism of posterior shoulder instability,with no consensus on appropriate treatment regimens. Further investigation is therefore required at both basic science and clinical levels.展开更多
We selected 106 hemiplegic patients with shoulder pain hospitalized after stroke from three hospi- tals in Nanjing, China between February 2007 and January 2012. All patients had complete clinical data sets and accoun...We selected 106 hemiplegic patients with shoulder pain hospitalized after stroke from three hospi- tals in Nanjing, China between February 2007 and January 2012. All patients had complete clinical data sets and accounted for 45.5% of the inpatients because of stroke. Results showed that the number of patients with hemiplegic shoulder pain post stroke increased yearly, attacking mainly males 50-69 years of age. Of 106 patients, there were 60 cases （56.6%） of adhesive capsulitis, 19 （17.9%） of shoulder subluxation, 14 （13.2%） of complex regional pain syndrome, and 13 （12.6%） of central pain. The main symptoms were shoulder pain （100%）, limit of shoulder mobility （98.1%）, and adhesion of the scapula （56.6%）. MRI of the shoulder showed tendon and ligament lesions （57.1%） and rotator cuff tear （38.1%）. 53.8% of central pain was related to the thalamus, in addition to the basal ganglia, brain stem, and cerebellopontine angle. Shoulder pain, upper limb motor function, and function independence were significantly improved after comprehensive rehabilitation. In par- ticular, electroacupuncture based on basic physical therapy exhibited efficacy on shoulder subluxa- tion and complex regional pain syndrome. Multiple linear regression results showed a negative re- lationship of efficacy of pain management with the attack period of shoulder pain, involvement of the posterior limb of the internal capsule, and duration between onset and rehabilitation treatment, but a positive correlation with pain-related education, pain regression period, and pain diagnosis.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51275443)Key Project of Ministry of Education of China(Grant No.212012)+2 种基金Hebei Provincial Natural Science Foundation of China(Grant No.E2012203034)Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20111333120004)Research Fund for Outstanding Youth in Higher Education Institutions of Hebei Province,China(Grant No.Y2011114)
文摘The application of the parallel mechanism is still limited in the humanoid robot fields, and the existing parallel humanoid robot joint has not yet been reflected the characteristics of the parallel mechanism completely, also failed to solve the problem, such as small workspace, effectively. From the structural and functional bionic point of view, a three degrees of freedom（DOFs） spherical parallel mechanism for the shoulder complex of the humanoid robot is presented. According to the structure and kinetic characteristics analysis of the human shoulder complex, 3-PSS/S（P for prismatic pair, S for spherical pair） is chosen as the original configuration for the shouder complex. Using genetic algorithm, the optimization of the 3-PSS/S spherical parallel mechanism is performed, and the orientation workspace of the prototype mechanism is enlarged obviously. Combining the practical structure characteristics of the human shouder complex, an offset output mode, which means the output rod of the mechanism turn to any direction at the point a certain distance from the rotation center of the mechanism, is put forward, which provide possibility for the consistent of the workspace of the mechanism and the actual motion space of the human body shoulder joint. The relationship of the attitude angles between different coordinate system is derived, which establishs the foundation for the motion descriptions under different conditions and control development. The 3-PSS/S spherical parallel mechanism is proposed for the shoulder complex, and the consistence of the workspace of the mechanism and the human shoulder complex is realized by the stuctural parameter optimization and the offset output design.
基金Supported by National Natural Science Foundation of China(Grant No.51275443)Key Project of Ministry of Education of China(Grant No.212012)+2 种基金Hebei Provincial Natural Science Foundation of China(Grant No.E2012203034)Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20111333120004)Research Fund for Outstanding Youth in Higher Education Institutions of Hebei Province,China(Grant No.Y2011114)
文摘The structure design for high ratio of carrying capacity to deadweight is one of the challenges for the bionic mechanism,while the problem concerning high carrying capacity has not yet be solved for the existing shoulder complex.A new type biomimetic shoulder complex,which adopts 3-PSS/S（P for prismatic pair,S for spherical pair） spherical parallel mechanism（SPM）,is proposed.The static equilibrium equations of each component are established by using the vector method and the equations for constrain forces with certain load are solved.Then the constrain force on the middle limb and that on the side limbs are compared in order to verify the unloading performance of the mechanism.In addition,the prototype mechanism of the shoulder complex is developed,and the force feedback experiment is conducted to verify the static analysis,which indicates that the middle limb suffers most of the external force and the effect of mechanics unloading is achieved.The 3-PSS/S spherical parallel mechanism is presented for the shoulder complex,and the realization of mechanics unloading is benefit for the improvement of the carrying capacity of the shoulder complex.
文摘Posterior instability of the shoulder is a rare condition and represents about 10% of shoulder instability. It has become more frequently recognized in the last year,even though it is more difficult to diagnose than anterior shoulder instability. As this form of shoulder pathology is somewhat rare,biomechanical knowledge is limited. The purpose of our study was to perform an extensive literature search,including PubMed and Medline,and to give an overview of the current knowledge on the biomechanics of posterior shoulder instability. The Pub Med/Medline databases were utilized,and all articles related to posterior shoulder instability and biomechanics were included to form a comprehensive compilation of current knowledge. A total of 93 articles were deemed relevant according to our inclusion and exclusion criteria. As expected with any newly acknowledged pathology,biomechanical studies on posterior shoulder instability remain limited in the literature. Current biomechanical models are performed in a static manner,which limits their translation for explaining a dynamic pathology. Newer models should incorporate dynamic stabiliza-tion of both the rotator cuff and scapulothoracic joint. There is a current lack of knowledge with regards to the pathomechanism of posterior shoulder instability,with no consensus on appropriate treatment regimens. Further investigation is therefore required at both basic science and clinical levels.
基金supported by the Qinglan Engineering of Higher Institutes Foundation for Outstanding Young Teachers of Jiangsu Province in China
文摘We selected 106 hemiplegic patients with shoulder pain hospitalized after stroke from three hospi- tals in Nanjing, China between February 2007 and January 2012. All patients had complete clinical data sets and accounted for 45.5% of the inpatients because of stroke. Results showed that the number of patients with hemiplegic shoulder pain post stroke increased yearly, attacking mainly males 50-69 years of age. Of 106 patients, there were 60 cases （56.6%） of adhesive capsulitis, 19 （17.9%） of shoulder subluxation, 14 （13.2%） of complex regional pain syndrome, and 13 （12.6%） of central pain. The main symptoms were shoulder pain （100%）, limit of shoulder mobility （98.1%）, and adhesion of the scapula （56.6%）. MRI of the shoulder showed tendon and ligament lesions （57.1%） and rotator cuff tear （38.1%）. 53.8% of central pain was related to the thalamus, in addition to the basal ganglia, brain stem, and cerebellopontine angle. Shoulder pain, upper limb motor function, and function independence were significantly improved after comprehensive rehabilitation. In par- ticular, electroacupuncture based on basic physical therapy exhibited efficacy on shoulder subluxa- tion and complex regional pain syndrome. Multiple linear regression results showed a negative re- lationship of efficacy of pain management with the attack period of shoulder pain, involvement of the posterior limb of the internal capsule, and duration between onset and rehabilitation treatment, but a positive correlation with pain-related education, pain regression period, and pain diagnosis.
