HOW: In a seated position in the leg curl machine, get set up with the leg straight and the pad just below the calf muscles. The other pad will be just above the kneecap, ensuring the leg does not move.
Hold onto the handles in front or to the side to stabilize the upper body and core.
Initiate the knee bend on one side by bringing the heel down. The opposite side is going to remain straight the entire time using the quadriceps or front of the thigh. Slowly return back to that starting position to where the knee is just about straight again.
Repeat for the prescribed repetitions.
FEEL: The back of the thigh is working.
COMPENSATION: Do not move the torso. Do not rotate the leg.