Some of your character’s joints or segments of geometry appear out-of-scale with their parent joints or other geometry. This can occur if you have the Segment Scale Compensate attribute for a joint turned on. When Segment Scale Compensate is on, scaling parent joints also scales lower joints in the chain, a process that conflicts with the HumanIK solver.
If you experience out-of-scale geometry or joints, make sure that you have Segment Scale Compensate turned off. The Segment Scale Compensate attribute is automatically turned off when you map the joint in a HumanIK skeleton definition. (See also Create a HumanIK skeleton definition.)
See Segment Scale Compensate for more information on this attribute.