302 P. P. DIAKONOW- — L'ANGLE SACRO-PELVIEN ET L'INCLINAISON 
nale que deux mémoires envisageant la question de points de vue 
tout différents; ceux de MM. Morris 1 et Le Damany 2 . 
M. Morris considère avant tout les articulations sacro-iliaques 
comme presque immovables (pp. 138 et 139) : « Being doubly 
wedge-shaped, wîth its broader surfaces ai t lie base and on the 
front, dislocations by forces acting from above downwards, as well 
as from before backwards, is amply provided against.... The anterior 
and downward displacements of the sacrum are likewise prevented 
by the interosseous and posterior sacro-scialic ligaments.... Thèse 
ligaments, too, while they resist forces directed downwards and 
forwards upon the sacrum, at the same time draw the bones more 
tightly together » 
L'action des contractions musculaires, comme telle, ne pourrait 
pas selon lui, attribuer aucun mouvement h cet articulation (p. 136) : 
« It will be noticed lhat each of the muscles arises fromboth bones, 
so thatduring their action they are not exercising any strain upon the 
ligaments of the articulation by pulling the bones aparl, as might 
be the case, if each muscle had been connected with only one 
bone. )) 
Les contractions du muscle sacro-épineux, en particulier, hormis 
leur pouvoir « érecteur du tronc » proprement dit, pourraient 
exercer une influence sur l'articulation de la dernière pièce lom- 
baire avec la première pièce sacrée sur l'inclinaison du pelvis 
(p. 110) : « The movements resemble, but are somewhat less li- 
mited, than those which occur between any two of the lumbar ver- 
tebra. As the diameter of the contiguos bones is less in an antero 
posterior than in a transverse direction, the backward and forward 
movements ne freer than the latéral. Thèse backward and forward 
movements, take place each time the sitting is exchanged for the 
standing position and vice versa. In rising from the sitting position 
the back is extended upon the pelvis at the sacro-lumbar union, 
and the pelvic inclination is also no doubt somewhat increased at 
the sacro-ilîac joints by the action of the erector spinae muscles. In 
1. Henry Morris, The anatomy of the joints of man. London, 1879. 
2. Le Damany, l'Angle sacro-pelvien; ses variations professionnelles, Journal de 
Vanatomie et tic la physiologie, 1909, N° 3. 
