  We report an anomalous local structural response in the CuO2 planes
associated with the appearance of charge inhomogeneities at low temperature in
underdoped but superconducting La2-x(Sr,Ba)xCuO4. We used pair distribution
function analysis of neutron powder diffraction data. The increase in the Cu-O
bond length distribution at low temperature has an onset temperature which
correlates with observations of charge and spin freezing seen by other probes.
