If this is truly a new symptom for you, then you should be evaluated soon by a neurologist
. When a patient reports that their leg drags when they walk, it is often do to a phenomenon called foot drop. This is when someone loses the ability, or has a reduced ability to raise the toes when a foot is brought forward. This causes one leg to drag as the toes fall and scrape across the ground. This is never a normal finding and is not a part of "old age". Probably the most common cause of foot drop is either a pinched nerve coming out of the back, or nerve damage due to another disease such as diabetes. If you are also having back pain, a slipped disc is a likely possibility.
I suggest that you schedule an appointment with a neurologist. He or she can take a detailed history of your symptoms, review your past medical history, and perform a thorough neurological exam. If you are displaying a foot drag or foot drop on your neurological exam, then the doctor
will most likely want to get an MRI
of your lower back to look for a herniated disc. If there is another more obvious cause for your foot drop, then the doctor will likely pursue the best initial treatment for you.