Electromyographic study of muscular overflow during precision handgrip.

This study was designed to describe the "overflow" of muscular activity to muscles beyond the essential prime mover and synergists during a precision handgrip exercise. Five subjects performed a 10-minute isometric handgrip exercise consisting of one-second contractions alternated with one-second rests. Four different force levels were assigned: 5, 15, 25, and 40 percent of each subject's maximum handgrip force.

Muscle formation in Ehlers-Danlos syndrome.

Ehlers-Danlos Syndrome (EDS) is a familial connective tissue disorder characterized by marked joint hypermobility, skin hyperdistensibility and fragility. To determine the influence of connective tissue hyperdistensibility on muscle function, a young woman with classic EDS underwent extensive muscle function testing which included a controlled strengthening exercise program. Quantitative muscle strength testing revealed generalized muscle weakness characteristic of this disease.

Muscular strength as an index of response to therapy in childhood dermatomyositis.

Dermatomyositis, an inflammatory disease of unknown etiology, causes diffuse symmetrical weakness and atrophy, muscular pain and tenderness, induration of muscles, and the tendency to develop contractures. The disease may follow a prolonged course which can best be managed with steroids and regulation of physical activity if there is an objective criterion for determining the extent of clinical involvement. In 6 children with dermatomyositis, quantitative muscular strength was compared with clinical evaluation of the state of the disease, serum enzyme levels, and other laboratory measures of systemic inflammation.