RESUMO
The important role played by the rotator cuff in the stability and movement of the glenohumeral joint make it susceptible to damage and injury in patients of all age groups. A number of extrinsic and intrinsic mechanisms have been described for the development of rotator cuff disease, although it is more likely that the actual etiology in any one individual is multifactorial. The key to successful management in a particular patient is an accurate diagnosis of the underlying cause by thorough clinical examination and the use of appropriate investigations. The mainstay of treatment of patients with rotator cuff disease is nonoperative. Surgical intervention is usually considered only after failure of at least 6 months of conservative therapy. However, there are a few situations where early surgical intervention is indicated.
Assuntos
Manguito Rotador , Algoritmos , Humanos , Manguito Rotador/patologia , Manguito Rotador/fisiopatologia , Manguito Rotador/cirurgia , Lesões do Manguito Rotador , Síndrome de Colisão do Ombro/diagnóstico , Síndrome de Colisão do Ombro/etiologia , Síndrome de Colisão do Ombro/cirurgia , Articulação do Ombro/patologia , Articulação do Ombro/fisiopatologia , Articulação do Ombro/cirurgia , Dor de Ombro/diagnóstico , Dor de Ombro/etiologia , Dor de Ombro/cirurgiaRESUMO
The motor unit is the basic unit for force production in a muscle. However, the position and shape of the territory of a motor unit within the muscle have not been defined precisely. The territories of five motor units in the cat tibialis anterior muscle were reconstructed three-dimensionally (3-D) from tracings of the glycogen-depleted fibers belonging to each unit. The motor unit territories did not span the entire length of the muscle and their cross-sectional areas tapered along the proximodistal axis producing a conical shape. In addition, the position of the territory of each unit shifted in an anterior-posterior plane along the longitudinal axis of the muscle, presumably as a consequence of the pinnation of the fibers. The area of the motor unit territory at any given level along the proximodistal axis was highly correlated with the number of fibers within the territory at that level. Connective tissue boundaries (outlining fascicles) appeared to have a strong influence on the shape of the territory, territories showed abrupt changes at connective tissue boundaries as groups of motor unit fibers within a fascicle often terminated together while motor unit fibers in neighboring fascicles did not terminate. It is likely that the mechanical impact of the recruitment of a motor unit is affected by the location and shape of motor units within the same muscle area.(ABSTRACT TRUNCATED AT 250 WORDS)