These symptoms include: 

Often loses temper
Is often touchy or easily annoyed
Is often angry and resentful
Often argues with authority figures or, for children and adolescents, with adults
Often actively defies or refuses to comply with requests from authority figures or with rules
Often deliberately annoys others
Often blames others for their mistakes or misbehavior
Has been spiteful or vindictive at least twice within the past six monthsThese behaviors are mostly directed towards an authority figure such as a teacher or a parent. Although these behaviors can be typical among siblings, they must be observed with individuals other than siblings for an ODD diagnosis. Children with ODD can be verbally aggressive. However, they do not display physical aggressiveness, a behavior observed in conduct disorder. Furthermore, they must be perpetuated for longer than six months and must be considered beyond a normal childs age, gender and culture to fit the diagnosis. For children under five years of age, they must occur on most days over a period of six months. For children over five years of age, they must occur at least once a week for at least six months. If symptoms are confined to only one setting, most commonly home, it is considered mild in severity. If it is observed in two settings, it is characterized as moderate, and if the symptoms are observed in three or more settings, it is considered severe.These patterns of behavior result in impairment at school or other social venues. Etiology
There is no specific element that has yet been identified as directly causing ODD.
Pes anserinus ("goose foot") refers to the conjoined tendons of three muscles of the thigh. It inserts onto the anteromedial (front and inside) surface of the proximal tibia. The muscles are the sartorius, gracilis and semitendinosus sometimes referred to as the guy ropes. The name "goose foot" arises from the three-pronged manner in which the conjoined tendon inserts onto the tibia. Structure
The three tendons, from front to back, that conjoin to form the pes anserinus come from the sartorius muscle, the gracilis muscle, and the semitendinosus muscle. It inserts onto the proximal anteromedial surface of the tibia.The pes anserinus is around 5 cm below the medial tibial joint line. It lies superficial to the tibial insertion of the medial collateral ligament of the knee. Clinical significance
Pes anserine bursitis is a cause of chronic knee pain and weakness. It occurs when the medial portion of the knee is inflamed. If the bursa underlying the tendons of the sartorius, gracilis, and semitendinosus gets irritated from overuse or injury, a person can develop this ailment. This condition usually occurs in athletes from overuse. This pathology is characterized by pain, swelling, and / or tenderness.The semitendinosus tendon can be used in certain techniques for reconstruction of the  anterior cruciate ligament. History
The name "goose foot" arises from the three-pronged manner in which the conjoined tendon inserts onto the tibia. Additional Images
References
External links
Pes anserinus at the Duke University Health Systems Orthopedics program