  A model of relativistic extended particle is considered with the help of
generalization of space-time inter-val. Ten additional dimensions are connected
with six rotational and four deformational degrees of freedom. An obtained
14-dimensional space is assumed to be an embedding one both for usual
space-time and for 10-dimensional internal space of rotational and
deformational variables. To describe such an internal space relativistic
generaliza-tions of inertia and deformation tensors are given. Independence of
internal and external motions from each other gives rise to splitting the
equation of motion and some conditions for 14-dimensional metric. Using the
14-dimensional ideology makes possible to assign a unique proper time for all
points of extended object, if the metric will be degenerate. Properties of an
internal space are discussed in details in the case of absence of spatial
rotations.
