03-12-2009, 11:00 PM
Proven, with science, even:
03-13-2009, 06:11 AM
I really don't like some of the wording in this article, but some of it is interesting for sure.
The usual suspects were used for this study: nine men and six women, all young (about 22 years old), healthy, and most likely university students. But here’s a cool thing: All participants were required to have at least one year’s experience with front and back squatting at least once a week. Yup, everybody in the study had been back and front squatting once a week for at least 52 weeks. I’m surprised they found 15 people!
While the lifters were “experienced” (unlike the commonly used untrained subjects), they weren’t huge people. Their average height was 171.2 cm (5’7”ish) and average weight was 69.7 kg (149.25 lb). Nor were they unusually strong people. On average the lifters’ 1 repetition maximum was 90% of their mass (61.8 kg -136.2 lb) for the back squat and 70% of their mass (48.5 kg - 106.9 lb) for the front squat. Not exactly world class but hey, we all have to begin somewhere, right? At least these folks were squatting, which is a great start!
I'm sorry but if you've been lifting in the squat for a year and you can't lift more than 90% of your mass you don't know how to squat, or you are weak as hell. I would not call these people experienced by any degree.
The individual then extends the hips and knees until reaching the beginning, with emphasis with keeping the back flat, the heels on the floor, and the knees aligned over the feet”.1
Knees can go past the feet and do in an good front squat or back squat. "Thighs parallel to the floor" is rather subjective, and I'm not joining to watch the videos.
EMG data showed no difference between front and back squats in any of the activities of muscles measured. That’s right, no difference in any of the quadriceps, hamstring or back muscles –- at least from a statistics standpoint. If you look at the data closely, there are some differences that in a larger group might be statistically significant. In cases with small differences between measures, statistics usually requires more samples –- in this case lifters -– to determine a difference. (But good luck finding more people with such desirable squat histories!)
Comparing just the averages, we find the back squat had higher hamstring activity (biceps femoris and semitendinous) compared to the front squat. The back squat also had lower quadriceps activity in two of the three muscles measured (vastus lateralis and rectus femoris), while vastus medialis activity was nearly identical in both squats. Last, front squats had higher back muscle (erector spinae) activity compared to back squats.
The first bold section makes sense - muscles just don't take a break between the two. Both squats use all those muscles. The important part that is I believe pretty common knowledge on this board is in the second bolded section.
While front squats showed no difference, or marginally less muscle activation, you have to remember that lifters also used less weight. So it really isn’t a surprise that compressive forces on the knee during front squats are lower.
This about sums up why I think this is a pretty poor scientific study. Some of it is right, some of it I chalk up to using poor subjects and poor methodology.
03-13-2009, 08:29 AM
I thought this was the most interesting part, even if it was from a different study:
"Oh, and machine squats were found to have 30-40% higher shear forces than free weight squats"
Andrews JG, Hay JG and Vaughan CL. Knee shear forces during a squat exercise using a barbell and a weight machine. Biomechanics VIII B.H. Matsui and K. Kobayashi, eds. Champaign: Human Kinetics, 1983: 923-927
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