On May 31, 2011, at approximately 6 p.m., plaintiff Julianne Haro, 37, a sales representative, was jogging downhill on a 400-yard-long horse trail, near the intersection of Etiwanda Avenue and Wilson Avenue, in Rancho Cucamonga. As she reached the bottom of the hill, she was struck from behind by an automobile tire that was rolled down the hill by 12-year-old David Uribe. Haro primarily claimed to her right shoulder, hip and knee, as well as aggravations of prior neck, back and head . Haro sued Luis Uribe (David’s father), individually and as David’s guardian ad litem. Haro also sued David’s friend who was with him when he rolled the tire, Andrew Villegas, by and through Andrew’s guardian ad litem, Maria Villegas (Andrew’s mother) and sued Andrew’s father, Daniel Villegas, individually. Haro alleged that David and Andrew were negligent for rolling the tire downhill. She also alleged that Luis Uribe was negligent in the supervision of David and that Daniel Villegas was negligent in the supervision of Andrew. Prior to trial, Haro dismissed Andrew and Daniel Villegas from the case. Haro also dismissed her negligent supervision claim against Luis Uribe. Thus, the matter proceeded to trial on Haro’s negligence claim against David Uribe only. Haro claimed that she was already 160 yards downhill when David initially rolled the tire. Thus, she claimed that David should have known that if he rolled the tire, it was likely to have hit her. David’s counsel contended that there was no negligence and that David acted reasonably for a 12-year-old boy in rolling the tire down the hill. Counsel also contended that Haro was contributorily negligent for wearing headphones at the time of the incident, which prevented her from hearing a neighbor, who was cooking on a bar-b-que nearby, yell at her to “look out.”, One day after the incident, Haro went to a hospital with abrasions to her arms and knees, and complaints of right knee, hip and shoulder pain. She also claimed she suffered a concussion, resulting in concussion syndrome, and claimed the incident aggravated pre-existing neck and back from a prior automobile accident. Haro was ultimately diagnosed with a torn right meniscus, bursitis of her right hip, and impingement syndrome in her right shoulder. She subsequently treated her conservatively, off-and-on, for three years. Her treatment consisted of physical therapy, acupuncture, and pain management through a neurosurgeon. Haro claimed that as a result of her condition, she was not been able to return to work as a sales representative for roughly two years. She also claimed that despite undergoing conservative treatment, she still cannot run like she used to. She alleged that as a result, she requires arthroscopic surgery on her right knee. However, Haro claimed that while her knee requires surgery, her shoulder and hip conditions will eventually resolve with some more physical therapy. Thus, Haro sought recovery of $200,000 in past lost earnings, $30,000 in past medical costs and $17,500 in future medical costs. She also sought recovery of $100,000 in damages for her past pain and suffering and $25,000 in damages for her future pain and suffering. David’s counsel argued that Haro’s only related to the subject incident were some minor abrasions/bruises and possibly some minor aggravations of Haro’s neck and back . Counsel further argued that Haro’s alleged meniscal tear, shoulder impingement, hip bursitis and new concussion were all unrelated to the accident and/or were pre-existing. Thus, David’s counsel contended reasonable medical treatment for Haro’s equaled roughly $2,000.