The London Podiatry Centre uses a number of criteria to decide whether a length difference should be treated.  The decision depends in part on the specific condition or whether there is or has been a history of back pain.  Older patients who have fully adjusted to their leg length difference without any obvious complications may tolerate treatment poorly.  Treatment also depends on a number of specific parameters associated with the gait assessment itself.  One example is the detailed analysis of pelvic motion and how this relates to the measured leg length discrepancy.  One would naturally expect increased pelvic tilt (downward motion of the pelvis) on the shorter side but in some cases the opposite occurs and this would contraindicate the addition of heel lifts or shoe modifications because the pelvic imbalance would worsen.