Samenvatting

The wrist allows the hand to combine
dorsopalmar flexion and radioulnar deviation, a
unique combination of functions that is made
possible by a highly complex system of joints. The
morphologic features of the carpal bones and
of the radiocarpal and intercarpal contacts can
be functionally interpreted by the mechanism
that underlies the movements of the hand to
the forearm. Displacements of the carpals take
place in longitudinal articulation chains, with the
proximal carpals having the position of an intercalated
bone. The three articulation chains,
radial, central, and ulnar, have interdependent
movements at the radiocarpal and midcarpal
levels. The linkage of movements in the longitudinal
direction is associated to a transverse
linkage by mutual joint contacts and by specific
ligamentous interconnections. Kinematic analyses
of the carpal joint motions have provided convincing
evidence that each motion of the hand
to the forearm demonstrates a specific motion
pattern of the carpal bones. The stability of the
carpus essentially depends on the integrity of the
ligamentous system which consists of interwoven
fiber bundles that differ in length, direction, and
mechanical properties. Distinct separations into
morphologic entities are difficult to make. From a
functional point of view, the ligamentous interconnections
can be regarded as a system that
passively restricts movements of the carpals on
one another and on the radius, but in a very
differentiated way. The ligamentous system
controls the linkage of the movements of the
carpals, with the geometries of the bones and of
the joint surfaces being, first of all, responsible
for the kinematic behavior of the carpal joint.