He welcome to Health care magic forum. According to your description, your husbands problelem is probably filarial fever
and motion may be secondary to indigestion
of the fever. Other causes may Ac arthritis
of the ankle with fever due to infection.
I advise you to consult a physician, for diagnosis and treatment. You may need to get the mid night blood smear for micro filaria in the blood. as microfilariae circulate in the blood stream only in the night, along with other routine tests for confermation of the disease.
Besides i advise you some diet recommendations as take more of easily digestible foods with more calories.
Avoid taking potato, other tubers, tomato, cauliflower, coconut egg, and sea foods as these foods increase the pain and swelling of the swollen joints.
Wishing for a quick recovery and thanks for calling.