squats
the quads loosen and the calves tighten so that you can put your leg down or so that you can stand up.
Quadriceps get exercised by- -knee extension exercises. -reverse mini squats. -reverse forward and side lunges. - descending staircase.
hamstrings
Electronic pulses from our brains travel down nerves and make the muscles contract, they are joined onto cartilage and that onto bones that make us move, the muscles store glogegen in muscle cells...