  When an inextensible elastic rod is 'injected' through a sliding sleeve
against a fixed constraint, configurational forces are developed, deeply
influencing the mechanical response. This effect, which is a consequence of the
change in length of the portion of the rod included between the sliding sleeve
and the fixed constraint, is theoretically demonstrated (via integration of the
elastica) and experimentally validated on a proof-of-concept structure
(displaying an interesting force reversal in the load/deflection diagram), to
provide conclusive evidence to mechanical phenomena relevant in several
technologies, including guide wire for artery catheterization, or wellbore
insertion of a steel pipe.
