  An extended test body moving in a curved spacetime does not typically follow
a geodesic, because of forces that arise from couplings between its multipole
moments and the ambient curvature. An illustration of this fact was provided by
Wisdom, who showed that the motion of a quasi-rigid body undergoing cyclic
changes of shape in a curved spacetime deviates, in general, from a geodesic.
Wisdom's analysis, however, was recently challenged on the grounds that the
body's motion should be described by the Mathisson-Papapetrou-Dixon equations,
and that these predict geodesic motion for the kind of body considered by
Wisdom. We attempt to shed some light on this matter by examining the motion of
an internally-moving tripod in Schwarzschild spacetime, as viewed by a Fermi
observer moving on a timelike geodesic. We find that the description of the
motion depends sensitively on a choice of cycle for the tripod's internal
motions, but also on a choice of "center of mass" for the tripod; a sensible
(though not unique) prescription for this "center of mass" produces a motion
that conforms with Wisdom's prediction: the tripod drifts away from the
observer, even when they are given identical initial conditions. We suggest
pathways of reconciliation between this conclusion and the null result that
apparently follows from the Mathisson-Papapetrou-Dixon equations of motion.
