'(<a href="http://www.j-archive.com/media/2008-06-23_DJ_19.jpg" target="_blank">Jimmy of the Clue Crew gives a physical demonstation.</a>)  Muscles work in pairs, so you can strengthen one by increasing flexibilty in the other. The hamstring curl strengthens the <a href="http://www.j-archive.com/media/2008-06-23_DJ_19a.jpg" target="_blank">hamstring</a> and allows <a href="http://www.j-archive.com/media/2008-06-23_DJ_19b.jpg" target="_blank">this muscle</a> at the front of the thigh to elongate'
the quadriceps
THE BODY HUMAN: Muscles work in pairs, so you can strengthen one by increasing flexibilty in the other. The hamstring curl strengthens the hamstring and allows this muscle at the front of the thigh to elongate
Muscles work in pairs, so you can strengthen one by increasing flexibilty in the other. The hamstring curl strengthens the hamstring and allows this muscle at the front of the thigh to elongate
Muscles work in pairs, so you can strengthen one by increasing flexibilty in the other. The hamstring curl strengthens the hamstring and allows this muscle at the front of the thigh to elongate
THE BODY HUMAN
the quadriceps
THE BODY HUMAN