  The sin-Gordon equation for Josephson junctions with arbitrary misaligned
anisotropic banks is derived. As an application, the problem of Josephson
vortices at twin planes of a YBCO-like material is considered. It is shown that
for an arbitrary orientation of these vortices relative to the crystal axes of
the banks, the junctions should experience a mechanical torque which is
evaluated. This torque and its angular dependence may, in principle, be
measured in small fields, since the flux penetration into twinned crystals
begins with nucleation of Josephson vortices at twin planes.
