Claimant is a 58 year old woman who earned her BA from Harris Stowe State College, and two Master's Degrees from Washington University and St. Louis University, respectively. Claimant's first job teaching math began in 1980 with St. Louis Job Corps. In 1983, Claimant went to work for Employer, where she continued to work as a teacher until her retirement in December 2012.
Claimant had two significant injuries prior to 2010. In 1998, she injured her neck in a motor vehicle accident. Claimant testified she was offered surgery, but chose conservative treatment including physical therapy that was effective in resolving her neck pain. In March 2006, Claimant was at work when she fell on crumbling steps. She put out her right hand to break her fall, and hurt her right arm, neck and hip. As a result of the 2006 fall, Claimant experienced burning, throbbing pain in her right arm. She treated with Dr. Roy Jerome Williams ${ }^{2}$, her personal physician, who diagnosed right cervical radiculopathy and ordered physical therapy. The pain, according to Claimant's testimony, went away, although she settled the workers' compensation claim flowing from the March 2006 injury for 5\% PPD of the whole body referable to the neck and 5 % PPD of the right hip.
There are no records prior to 2007 in evidence, although the physical therapy records confirm a history of neck pain dating back to the 1998 MVA, and the problems with the right shoulder and neck following the 2006 fall. Claimant's rating doctor, Dr. David Volarich, noted that a cervical MRI from May 18, 2006 ordered by Dr. Doll showed advanced degenerative disc disease at C4-5, C5-6, and C6-7 with spondylotic spurs and dorsal projecting bony spurs which abutted the chord. Dr. William's handwritten records mention ongoing or resolving symptoms of the neck, right upper extremity, flank and/or back pain in 11 of the 15 entries between 2007 and the date of injury. The prior problems in the neck and right shoulder seemed to wax and wane, but improved with treatment.
On Wednesday, September 15, 2010, around 10:00 in the morning, Claimant was standing at the whiteboard in the front of the room instructing the class. She stood with her arm raised, writing on the board, with her head slightly turned. Suddenly, she felt something strike her on the right side of her head, above her glasses. Startled, she turned her head quickly towards in the direction of the projectile, and her body followed. She did not fall, trip or stumble. Claimant felt immediate radiating neck pain. Her head also hurt.
Upon inspection, Claimant discovered she had been struck by a ping pong ball-sized wad of crumpled paper wrapped around sunflower seed hulls. She confronted the person whose name was written on the paper, and although he denied having thrown the paper, Claimant sent a request to have the student removed from the classroom. Claimant felt violated, upset, and ang