forte is a medicine containing glucosamine
and chondroitin and is used in person suffering from osteoarthritis
.It helps to repair the damage caused by age related changes or disease to a certain extent.
A good effect of this medicine can be seen after using it for a longer period.
Also along with this medicine he should take anti inflammatory and analgesic
to help relieve the pain.
For more information you should write in detail about the problem your father is having.