<prompt> Whip-lash injury is caused due to:A fall from a height.Acute hyperextension of the spine.A blow on top to head.Acute hyper flexion of the spine.  <response>: Ans. is b i.e. acute hyperextension of the spine Whiplash injuryIt is a term given to soft tissue sprains of the neck seen commonly after automobile accidents. It is mainly seen after hyperextension of the spine however it can also occur with flexion and rotationMechanism of injuryIt usually follows a rear end collision of automobile in which the occupants body is thrown forwards and the head jerked backwards with hyperextension of the lower cervical spine.Clinical features: -Pain Stiffness of the neck appears within 12 to 48 hrs. of accidentsNeck tendernessNeurological deficits uncommonDiagnosis -X-ray - straightening out of the normal cervical lordosis a sign of muscle spasmMRI -may show disc abnormalities.TreatmentSimple pain relieving methods analgesics needed for the first few weeks.Then physiotherapy is needed.collars are more likely to hinder than to help recovery 