Leg Training Myths

You know the guy who floats around the gym nit-picking everybody's technique? The guy who offers constructive criticism without being constructive? Well, we got sick of listening to his pseudo-knowledge about leg training, so we decided to give you the low down to some of the most common "tips" you hear.

The Parallel Universe

Myths:
"When doing leg presses, don't go more than half-way down."
"When squatting, don't go below parallel."

Real-World Response
Have you ever watched kids learn to stand? They begin in a full squat. In fact, the fetal position is a full squat. That's how your knee actually developed — in the full squat position.

Don't come back at me saying that a fetal position isn't loaded. That statement actually proves my point. It's not the position itself that's dangerous. If you're an idiot and don't know how to load properly, then we have big problems.

Ask any orthopedic surgeon or physical therapist at what degree of knee-bend one performs the "drawer test?" It's at 90 degrees. In this position, the knee joint is most unstable. If you're trying to assess the integrity of the ligaments, you want minimal interference from other structures.

You can imagine how much force is on the knee ligaments if the athlete descends with a weight and then at the most unstable point (90 degrees), reverses momentum and accelerates in the opposite direction. Couple this with the fact that nearly everyone is capable of squatting more weight to parallel than to the full squat position, and you set your body up for a problem.

Myth:

"Don't let your knee pass your foot during lunges."

Real-World Response
This one is really easy. My answer is, what about the other knee? In a lunge, it's apparently too dangerous for the knee of the front leg to extend past the toes. Meanwhile the knee of the back leg is past the toes the whole time.

I've had people respond by saying that there's no load on the back leg during a lunge. Okay then, put 70kg on your back and go down to the bottom of a lunge. Now lift your back foot off the floor. I rest my case.

Scientific Response
When talking about knees going forward, one study jumps out. Fry, Smith, and Schilling (2003) examined joint kinetics during back squats under two conditions.
The first condition placed a board in front of the participants' shins, which restricted forward displacement of the knee. In the second condition, movement wasn't restricted at all. They squatted normally and the knees were allowed to pass the toes.

The researchers found that restricting the forward excursion of the knees during the squat increased anterior lean of the trunk and promoted an increased "internal angle at the knees and ankles."

The results showed a 22% decrease in knee torque and a 1070% increase in hip torque! That stress has to go somewhere. Keeping the knees behind the toes definitely reduces the forces on the knee, but those forces were transferred more than tenfold to the hips and lower back.

Obviously this study was in regard to squatting. However, the knee angle in a lunge would be similar and we could expect similar findings.

Wrap-Up
• For strength and joint health, using the full range of motion on squats is more beneficial than squatting to parallel.
• Squatting deep isn't any more hazardous to the knees than squatting shallow.
• Keeping your knees behind your toes when squatting or lunging is a little better for your knees, but much, much worse for your hips and lower back.