Could The Pain In The Lower Back While Walking Be Due To Sciatica?

on 21.08.2011 we took our father to Dr. S Dalai, Vertico vein specialist from South india who visits Kolkata, west Bengal, Indai twice a week.. After seeing and listening he said this case is related to sciatica and referred to another doctor. We took appointment of that Dr. on 31.08.2011 . My father aged about 62 yrs can t walk properly. He felt pain lower back leg pain during walking and sleeping. Please advise. YYYY@YYYY