RESUMO
An instrumented wheel system for three-dimensional kinetic analysis of upper extremity during wheelchair propulsion has been designed and validated. This system allows the direct measurements of three-dimensional dynamic forces and moments on the handrim during wheelchair propulsion in a laboratory setting as well as in the field. Static loading tests showed a high linearity and little drift (coefficient of determination, r2 > 0.999). Under dynamic loading, the instrumented wheel provided the well-matched measurement forces and moments with the predicted values from the inverse dynamic method using video-based kinematic data (correlation coefficient, p > 0.97). The three-dimensional handrim forces and moments during wheelchair propulsion by a non-disabled subject were demonstrated.
Assuntos
Mãos/fisiologia , Locomoção/fisiologia , Atividade Motora/fisiologia , Análise Numérica Assistida por Computador , Processamento de Sinais Assistido por Computador , Gravação de Videoteipe , Cadeiras de Rodas , Fenômenos Biomecânicos , Humanos , Análise de Regressão , Reprodutibilidade dos Testes , Cadeiras de Rodas/efeitos adversosRESUMO
This study examines psychoanalytic psychology, theories of cognitive style, and cognitive developmental psychology to examine the relationship between cognitive style and defensive style. A new set of cognitive styles of visual attention is formulated at the following developmental levels: (1) global, (2) local, (3) global-plus-local at the concrete operational level, and (4) global-plus-local at the formal operational level, 50 subjects were administered global-local sorting tasks, the Sentence Preference Test, the Embedded Figures Test, and the Defense Style Questionnaire. Analysis provided mixed support for the hypothesized cognition-defense relationship. Results suggested that the "pure" character types are not typical and that their styles of cognition and defense are positively correlated, not independent as expected. However, possible measurement problems preclude any firm conclusions at this time.
Assuntos
Mecanismos de Defesa , Controle Interno-Externo , Reconhecimento Visual de Modelos , Adulto , Atenção , Aprendizagem por Discriminação , Feminino , Humanos , Masculino , Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Orientação , Inventário de Personalidade , Teoria PsicanalíticaRESUMO
Total elbow arthroplasty is often used to replace elbow joints that have been severely damaged by arthritis or trauma. A great disparity of designs exists, however, in currently available elbow prostheses. This study evaluated the intrinsic stability of one popular resurfacing implant, the Capitellocondylar (Johnson and Johnson Orthopaedics, Inc., New Brunswick, NJ) total elbow. The in vitro response of this unconstrained prosthesis to valgus-varus and supination-pronation loading was investigated using a materials testing machine. The influence of compressive loading and flexion angle on the intrinsic stability of the prosthesis was studied. The Capitellocondylar prosthesis was found to have little intrinsic constraint, relying on external forces for component stabilization. Dislocations were common at 111 N of compressive loading, while larger loads progressively stabilized the prosthesis. Joint flexion angle had little influence on the intrinsic constraint of the implant except to increase varus stability at lower flexion angles. The Capitellocondylar total elbow prosthesis, as designed by F. C. Ewald, behaves as an unconstrained implant. Adequate soft tissue supports, which are properly balanced to provide controlled loading, are essential to prevent instability of this arthroplasty.
