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).
Bakerâs (popliteal) cyst behind knee: Causes, symptoms, and natural treatment options. A Bakerâs cyst (popliteal) is a fluid-filled sac that causes a bulge, along with feelings of tightness, behind the knee. The pain can worsen when the leg is extended at the knee or when the knee flexes as a result of activity.