Aerosmith guitarist Joe Perry was injured Thursday afternoon when he was rear-ended in Middleborough, Massachusetts.  He was riding his 2009 Ducati Monster 696 motorcycle when he was struck from behind by an automobile drived by 62-year old Linda O'Brien.  Damage to both vehicles was minimal because both were moving at slow speeds, but Ms. O'brien was cited for following too closely.  Perry was taken to a local hospital, where he was treated and released within two hours.  Hospital officials refused to disclose the nature of the injuries to Perry, who lives in nearby Duxbury.  The accident is not expected to have any effect on Aerosmith's touring schedule.