Instantaneous Angle of Rotation (IAR) for the mid-lower cervical spine in flexion/ extension is _____. MCQ 07:44 Biomechanics Instantaneous Angle of Rotation (IAR) for the mid-lower cervical spine in flexion/ extension is _____. a. the anterior body of the vertebra below b. the anterior body of the vertebra above c. the spinal cord d. the IVD Answer: a Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+