What is ADHD? ADHD (attention deficit-hyperactivity disorder) affects both adults and school-aged children. Symptoms include restlessness, difficulty paying attention, and hyperactivity. The causes of ADHD are unknown, however factors such as diet, environment and genetics may contribute to symptoms.
The knee muscles control how the knee joint and patella move. There are two main groups of muscles, the quadriceps and the hamstrings, as well as a small muscle behind the knee (popliteus).
1) Bakers Cyst. What is it: Inflammation of the popliteal bursa (fluid filled sac) at the back of the knee. It is the most common cause of pain behind the knee. Symptoms: Swelling (like a small water balloon), tightness and pain behind the knee. Aggravating Activities: Bending and straightening the knee, walking, kneeling. Onset: Can come on after a blow to the back of the knee but usually comes on gradually.