It can be other things not related to Frozen shoulder, such as, Cervical spondylosis or Carpal Tunnel.
You can ask if someone is near him or with him to download the app and get him consulted because giving medicine is also important so even if you get a consult on call, but it's imperative to get the medicine. So how will you get that!
Next Steps
It's better to get a video consult because then the doctor can assess his movements also and that will be helpful via this app if you are looking online or to get him to the nearest safest clinic for a proper examination and then follow the treatment plan.
Health Tips
It normally takes 3 to 4 months to heal but it also depends on your father current health levels like his
Calcium, Vit D and Vit
B12 levels.