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).
The muscles of the knee include the quadriceps, hamstrings, and the muscles of the calf. These muscles work in groups to flex, extend and stabilize the knee joint. These motions of the knee allow the body to perform such important movements as walking, running, kicking, and jumping.