This exercise is best performed on a machine, one leg at a time. With few exceptions, most machines are similar in structure to the one shown below. Higher-quality equipment usually allows you to adjust the seat and leg roller; set them so you situate your knee on the axis of the machine, with the ankle just below the leg roller
Steps
Options: A variation of this exercise involves pulling the bar in front of your body to about mid-chest height. If you have time, perform both exercises. If time is limited, select one or alternate between the two.
Keep control while raising and lowering the weight. Don’t let the bar swing back excessively as you return to a starting position