Has anyone living with FTD (frontal temporal dementia) family member had the person be very stiff when walking, contracture of an extremity?

Check with doctor and go on FTD wrbsites. You'll probably find references to MND motor neuron disease, something on the FTD spectrum. It is likely to get worse as the brain degeneration continues. In general FTD may start out as semantic (language problems), behavioral (screw up in judgement and behavior), or motor (muscle) function. As time passes they may sort of mush together.

I think if you got updated brain imaging you will see that the damage has gone well beyond the front and is invading the temporal region more and more. Ask the MD about muscle relaxers and pain relief.