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bibliography * The PainScience Bibliography contains plain language summaries of thousands of scientific papers and others sources, like a specialized blog. This page is about a single scientific paper in the bibliography, Machleder 1986.

The anterior scalene muscle in thoracic outlet compression syndrome. Histochemical and morphometric studies


original abstractAbstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.

Histochemical studies and morphometric fiber type analysis were done on biopsy specimens of anterior scalene muscle (ASM) from patients with thoracic outlet compression syndrome (TOS), without structural abnormality. Hypertrophy and atrophy factors were determined from muscle fiber histograms of ASM from controls, patients with TOS, and after scalene tenotomy. Scalene muscle from patients with TOS showed marked type 1 (tonic contracting) fiber predominance (85.1% +/- 5.1%) and type 1 fiber hypertrophy (55.6 +/- 2.7 microns). After tenotomy there is a reduction of type 1 fiber representation, selective atrophy in the type 1 fiber system (atrophy factor, 0.66 +/- 0.24), and increase of type 2 fibers. These distinctive changes indicate that ASM is uniquely structured in fiber composition to sustain prolonged contraction. The ASM in patients with TOS demonstrates an extraordinary adaptive transformation and recruitment response in the type 1 fiber system reflecting chronic increased tone or motor neuron stimulation. These observations form a basis for clarifying the structural and pathophysiologic changes in TOS.

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This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights: