A contribution to the study of the mechanics of the spine / by Robert W. Lovett.

  • Lovett, Robert W. (Robert Williamson), 1859-1924.
Date:
1903
Catalogue details

Licence: In copyright

Credit: A contribution to the study of the mechanics of the spine / by Robert W. Lovett. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    This is the case because from a mechanical point of view the spine is a flexible rod permanently curved by the physiological curves in the antero posterior plane. Side bending necessitates movement in another plane and consequently a twist, and twisting for a similar reason causes side bending. In lateral curvature the problem is simplified by a recognition of these facts. Any lateral yielding of the spine at any part must be accompanied by a twist of the spine and the transverse axis of the shoulder girdle will no longer be parallel to that of the pelvis. As the lateral curve increases, the twist will tend to increase. But in addition to being a flexible rod the human spine must be regarded as a flexible rod endowed with a sense of equilibrium and adjustment. In a general way in the upright posi- tion the head must be kept over the base of support and the head pointing approximately straight ahead. This is a matter of continual and in- stinctive muscular effort on the part of the patient. If now a lateral curve has been acquired, the shoulders will be twisted in their relation to the pelvis and as the curve increases, the twist would naturally increase. That a twist exists in each case of lateral curve is easily seen in any case of postural lateral curvature looked down on from above in the standing position, wThen the shoulders can be seen to be no longer parallel to the pelvis. But the twist cannot increase beyond a certain point because of the patient’s instinctive effort to keep the shoulders parallel to the pelvis. The lateral curve is a present and probably increasing factor, and to bring the shoulders again parallel to the pelvis, a compensating twist must be added to the one already existing which results in the phenome- non known as rotation and enables the shoulders to be again brought into approximate parallelism with the pelvis. To this resultant combination of two twists which results in the prominence of the ribs on one side of the spine, or of the transverse processes of the lumbar vertebrae on one side of the spine, or to both together, the name “ rotation ” has been applied in the nomenclature of lateral curvature. REFERENCES. 1. Lorenz.—Path, und Ther. der Seitl. Ruckgrats-Yerkrummimgen, p. 28, Wien, 1886. 2. Enlenburg.—Die Seitl. Ruckgrats-Yerkrummimgen, Berlin, 1876, p. 116. 3. Hughes.—Archiv fur Anat., 1892, 265. 4. Bibliography in Riedinger.—Morph, und Mech. der Skol., Wiesbaden, 1901. Wullstein.--Die Skoliose, Stuttgart, 1902.