458 HUMAN REMAINS FROM THE NORTH KURGAN. 
of the neck which are subjected to the pressure, while the central depressed part 
is less affected. Accordingly the cartilaginous covering of the joint is spread 
especially over the two lateral swellings of the neck; the depression between these 
remains free (plate 95, fig. 3, 6). But now the two swellings act very differently. 
The medial swelling presents a direct continuation of the medial edge of the sur- 
face of the trochlea, as we can see by taking a corresponding impression with 
lead wire (fig. 495, e). The action of the lateral swelling is wholly different. 
It rises sharply from the surface of the trochlea (fig. 495, f). Consequently, when 
the foot is flexed in a dorsal direction, the medial swelling slides smoothly under 
the articular surface of the tibia, without altering essentially the edge of the latter; 
at most it deepens a little more the depression of the articular surface at the base 
of the malleolus. On the other hand, the lateral swelling presses itself against 
the edge of the articular surface, flattens it and produces the above-mentioned 
overspreading of the cartilage on the anterior surface of the bone. If this explana- 
tion is right, the edges of the cartilage-covered surfaces on the astragalus and 
tibia must fit each other exactly, when brought into an extreme dorsiflexion. 
Indeed that is so in our case. ‘This, too, gives a certain proof that our astragalus 
belongs really to the fragment of tibia. 
That the squatting position gives rise to this strong dorsal flexion is shown 
by the fact that the change just described on the lower joint is often accompanied 
by a corresponding one on the upper joint. We find there often a rounding 
off of the posterior edge of the joint-surface, which shows itself especially on the 
lateral joint-groove and causes the joint-groove to appear convex in its posterior 
segment. Also this characteristic is indicated on the left tibia head, even if 
not very marked (fig. 495,@). It would correspond about to No. 2-3 of Thomson’s 
scheme (1890, p. 211). The cause of this variation is doubtless to be found in the 
strong flexure of the knee, through which the posterior, upper surface of the 
condyles is brought against the posterior edge of the joint-surface of the tibia. 
It is at least doubtful whether the backward divergence of the head of the tibia 
(plate 95, fig. 2) is also produced, or increased, by strong bending of the knee, 
since it seems to occur in cases where such a function can not be shown as a cause. 
An examination of this divergence by Manouvrier’s method (1893, p. 231) gave 
an angle of inclination of 10°. The angle of retroversion could not be measured; 
with the considerable curvature of the tibia it is not possible to speak of a straight 
diaphysis axis so that we have no criterion for the position. An inclination angle 
of 10° lies perfectly within the range of variation of modern Europeans and exceeds 
but little the average value, 8.5°, found by Manouvrier for 72 European tibize 
(French) (1893, p. 236). The described curvature of the thigh bone, as well as 
of the tibia, by enlarging the space for the flexure muscles of the upper and lower 
part of the leg, facilitates squatting; this is so self-evident that one might consider 
whether this habit did not contribute to the increase of those curvatures. 
Also the low position of the condylus medialis tibiz seems to be more common 
among ‘primitive ‘peoples (plate 96, fig. 1). 
