It seems both problem different.
leg injury can produce weak leg but not shivering to whole body , these are Parkinson type old age problems .
He need attaintion from both side , physio to complete the rehabilitation .
Physician for Parkinson.
Your observations of shivering in right leg just after injury was due to weakness in muscles.
These days' s shivering have fault in brain , common , Parkinson , happens to many oldes
Next Steps
take care of right leg , because of central shivering , this place is prone to highly unstable , result fall.
Health Tips
start rehab soon