A Fifty Four Year Old Nephew Was Recently Hospitalized With

A fifty four year old nephew was recently hospitalized with pneumonia and treated with intravenous antibiotics. He has a history of heavy smoking and a prior hospitalization for pneumonia which required placement of a chest tube about 8 years ago. He is slowly recovering but has generalized weakness and pain going down both legs from upper thigh to ankle. What might be the cause of the leg pain and is there treatment for it?