Lateral curvature of the spine and round shoulders . ated in thecenter of gravity, and the de-termination of the relation be-tween the center of gravity andthe bearing points determinesthe lines of stress. The Defects of the UprightPosition.—An important mat-ter in the mechanics of thespine and its appendages is that it is evolved with comparativelyslight modifications from the quadruped spine, and, in fact, ishardly more than the quadruped spine set upright. In thequadruped the spine is a horizontal sustaining structure archedupward, supported at one end by two anterior limbs and at theother
Lateral curvature of the spine and round shoulders . ated in thecenter of gravity, and the de-termination of the relation be-tween the center of gravity andthe bearing points determinesthe lines of stress. The Defects of the UprightPosition.—An important mat-ter in the mechanics of thespine and its appendages is that it is evolved with comparativelyslight modifications from the quadruped spine, and, in fact, ishardly more than the quadruped spine set upright. In thequadruped the spine is a horizontal sustaining structure archedupward, supported at one end by two anterior limbs and at theother by two posterior limbs; the viscera hang directly downfrom this, being supported by ligaments and attachrnents at rightangles to the supporting structure. On account of the angle of theribs the thoracic cavity is helped in inspiration by gravity as theribs fall into the position of thoracic expansion, but they must bepulled up to contract the thorax; and, finally, equilibrium is muchmore easily maintained than in the biped, because the supporting. Fig. 32.—The Right Side of the PelvisOF the Cadaver is Raised and the UpperPart of the Spine Falls to the Left,Making a Lateral Curve Convex to theRight. MECHANISM OF SCOLIOSIS 45 base is broad and the weight of the mass to be supported is compara-tively small. When this structure with only comparatively sHght modificationsis set on end and made to fulfil the functions of a weight-bearingcolumn in a plane at right angles to that for which it is best adapted,certain unfavorable factors are introduced which serve as distinct
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Keywords: ., bookauthorlovettrobertwrobertwi, bookcentury1900, bookdecade1910
