To determine the motion analysis ofthe normal lumbar spine, 61 ofthe 152 radiograps of healty young medical students in the neutral erect, active maximm flexon and maximum extensionpositions were carefully selected. Analysis of coordinates of the etension-to-flexion motion of each vertebra. İn extension - to - flexion motion, the L4 verte-bra shoved a translation- predominant motion characterristic.
The L5 vertebra had a rotation-prodominant motion characteristic.
Keywords: Spine, motion, lumbar spine