My father fears that he is gonna fall, and is very inactive. How can i help him to overcome this ?

Is he only fearful of falling, or is he fearful in general? Agree with getting PT to address balance and OT to address environmental issues, but anxiety is a REAL issue for many elders.

There are antidepressants with good antianxiety properties that might be used to address the underlying fear and depression that we often see in elders, which exist due to changes in brain chemistry. Just something to think about.

Have your father's doctor prescribe balance therapy. My mother did this at a PT clinic earlier this year. If the patient is compliant, it can be very helpful.

Overcome his fear of falling, or provide home adaptations and equipment to make sure that he does not fall?

The point is, is your father's fear of falling based on physical difficulties or not?

Physical therapy focused on falls prevention includes exercises to improve sense of balance and strengthen the key muscle groups involved.

Occupational therapy involves an assessment of your father's living environment, taking into account his physical needs, Activities of Daily Living and personal preferences, followed by recommendations about ways to help him get about safely.

But the third factor that might be at work is that your father is would just rather sit tight in his chair than do much of anything. In that case, the fear of falling is a combination of excuse, plus loss of balance and physical ability because he's been scrunched up in a heap for too long. You can see how the vicious circle would develop.

Don't ask more of him than he is happy with, but if it were me I'd book a couple of home visits and see how it went.