Use the Leg Press Wisely
To be clear, Charles R. Poliquin preferred squats over leg presses. But he insisted that if you’re going to perform leg presses, you better do them right.
One of the Strength Sensei’s concerns about the leg press was that because the back is supported during the leg press, it can cause muscular imbalances if performed excessively. For this reason, you should assume that if your leg press poundages increase, this may not be reflected in how much you can squat.
Another issue with the leg press is that if your legs flex too much (against your chest), you may round your lower back and place excessive stress on your spine. Flexing your spine may also occur if you lower or press the weight too quickly.
Finally, avoid getting locked into a single method of performing the exercise. Consider experimenting with different foot positions (higher/lower, wider/narrower, feet neutral/feet out) to stimulate the muscles differently and enhance muscle growth. (TSS)
BOTTOM LINE: Avoid using an excessive range of motion in the leg press, moving the weight too rapidly, or performing it at the exclusion of squats.
— Miloš Šarčev photo