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).
Get the Latest health and medical information delivered direct to your inbox! Hamstring: The prominent tendons at the back of the knee. They are the sidewalls of the hollow behind the knee. (This hollow is called the popliteal space). Both hamstrings connect to muscles that flex the knee.A pulled hamstring is a common athletic injury.The ham of hamstring comes from an Old Teutonic word ham meaning crooked.hey are the sidewalls of the hollow behind the knee. (This hollow is called the popliteal space). Both hamstrings connect to muscles that flex the knee. A pulled hamstring is a common athletic injury. The ham of hamstring comes from an Old Teutonic word ham meaning crooked.