Medical Officers of the Army of India.
65
European skeletons, according to Sir William Turner, have it the reverse of this
in 10 out of 12, and in the remaining two the diameters are equal.
It is about from the 3rd lumbar to the sacro-vertebral articulation that
motion is greatest, and hence, in any race of men, if the power of flexion is more
than usually cultivated by habit or custom, it will be in this region that morpho-
logical changes will occur, called up by increased physiological function.
The foregoing has reference to 28 vertebral columns which belonged to fully
grown adults. In Table No. 3 (Nos. XXII-XXVIII) are measurements of bones
varying in age from 12-21 years. Certain interesting points are noticeable in them.
In Nos. XXII-XXIV, and XXVI the total anterior diameter of the lumbar
region is greater than the posterior (87 mm.—85mm.
:85mm. :—80mm.:—71mm.: — 6 1
m m .
) .
The respective ages of the skeletons were 12, 14, and 12 years. It will be noted
that in these three the diameters of the individual vertebræ are either equal or
differ very slightly. The epiphyseal plates have, not as yet appeared. The
layers of hyaline cartilage (which invest the terminal faces of each vertebra,
and have the epiphyseal plates developed in them, and by which the interverte-
bral discs are attached) are comparatively thick at this age, and will be easily
modified by function. This hyaline cartilage is of course macerated off and is
not included in the measurements. Sir William Turner, quoting Aeby and
Ravenal, states that in the new-born child neither the vertebral bodies nor the
discs are wedge-shaped, and that the anterior and posterior vertical diameters
are equal. My observations above point to the conclusion that up to 12 years
of age none of the changes typical of the Panjabi lumbar region have taken
place in the bodies of the vertebræ, so that Sir William Turner's question, " At
what period of life do the bodies of the lumbar vertebræ assume the wedge-
shaped forms ?" may be answered that it does not at least occur before 12 years
of age. In Nos. XXIII, XXV, XXVII, and XXVIII, the posterior diameter
exceeds the anterior (94 mm.—94mm.: 95mm.: 98mm.: 78
mm.:—79 mm.:
91 mm.—92 mm. : . )
with the exception of No. XXIII. Now the epiphyseal plates are appearing, and
slight changes, typical of the Panjabi, are occurring in the centra of the vertebræ.
The spines were 19-21 years old. It is probable that the growth, giving a lumbar
vertebra, its wedge-shaped form occurs in the epiphysary area, and that it
progresses between puberty and 25 years of age. The base of the wedge
(deepest part of the centrum) in the Panjabi is turned backwards, and the
changes eventuate as the racial type matures.
2. As to the size and thickness of the intervertebral discs.— I have been
able to bring forward data of seven vertebral columns showing the thickness of
the fibro-cartilages in the lumbar region (Table 4, Nos. XXIX-XXXV). Professor
Macalister (Text Book of Human Anatomy) says, in speaking of the discs in Euro-
pean bodies, " Those in the dorsal region are, if anything, higher behind, those
in the lumbar are higher in the front. The last or lumbo-sacral is wedge
shaped and 2.6 higher in front." It is not stated how much higher the lumbar
K