The present study was carried out on 200 subjects with 100 asymptomatic control ( 50 male and 50 female) and 100 symptomatic cases( 50 male and 50 female). The symptomatic subjects were having complaints of low backache, sciatica and neurogenic claudication of more than 6 months duration. Their age group was between 30 -80 years. The aim of the study was to find out the Jone__ampersandsignrsquo;s spinal index on plain radiographs of the lumbar spine in normal and symptomatic subjects and to compare them. It was found that the lower normal limit of the Jone__ampersandsignrsquo;s spinal index was 1:2.21 which indicated a wider canal. The highest value observed in controls was 1:6.08. Jone__ampersandsignrsquo;s Spinal Index, when positive is suggestive of narrowing of the lumbar spinal canal but when negative does not exclude the possibility of narrow spinal canal