The Front Squat vs. Back Squat

Image courtesy of benbruno.com

Back in February there was a series of articles written by Jim Reeves posted on Ben Bruno's website comparing front squats to back squats.  In the second article of this series, which can be found here, there are pictures of a man at the bottom of both his front squat and his back squat.  The pictures are then (poorly) analyzed for the motion that happened at specific joints throughout the movement and conclusions are drawn based on these measurements and then further discussed in the third installment of this article series, found here.

Now, I will not waste your time ranting about how poor of a job was done analyzing joint motion, but just so you know I am not full of crap, I will give you one example.

Image courtesy of benbruno.com

The caption for this photo reads "...the angle calculated for the hip and ankle motion measured at the bottom of the squat motion."  Two things.  First, where the shaded area is indicating "hip" motion, that is actually indicating how far forward the torso is leaning, the position of which is probably a product of both hip flexion and trunk flexion but the shaded area is really only indicating trunk motion relative to the alleged positioning of the femur.  Even then, the number is inaccurate because right now it would indicate that if your torso is fully folded up on top of your thighs you are very close to zero degrees of trunk/hip/whatever the heck he is trying to measure flexion when, in fact, 180 degrees of motion would be a more accurate assessment.  Likewise, in this picture, 136.2 degrees of motion would be the correct assessment of motion, assuming the depicted femur and spine positions are remotely accurate.

Second, and going along the same lines as what I just said, if you are actually looking at that picture and trying to determine "hip" motion, you, once again, have to look at the opposite side of the axis and measure to the femur rather than where the spine currently is relative to the femur.  Reason being when you stand straight up, as you normally do at the top of a squat, it would be said that you are in a position that is closer to zero degrees of hip flexion rather than 180 degrees of hip flexion.  Therefore, just as above, the number of degrees that are assigned to "hip flexion" should be much greater than what is currently presented in the article.

Okay, I tried to hold myself back from a rant.  I think I did alright.  If not, I apologize, but I felt it was a point that needed to be made.  Now, on to the major issue at hand.

So the issue, among other things, of joint motion is brought up in these articles and how during front squats there is "this much joint motion here" and during back squats there is "this much joint motion there", etc.  I have already demonstrated how these assessments are not accurately done, but nevertheless you can kind of eyeball it and see what they are talking about even though their numbers are off and therefore their argument is misguided.  BUT, but but but but BUT what was COMPLETELY left out of  the discussion was 1) placement of the load and 2) direction of the line of force.  Without knowing and/or discussing these, any argument being made in regards to muscular participation and requirement as well as the effects of the motion and load on the joints themselves is incomplete and, until this information is taken into consideration, invalid.

Why is the placement of the load and the direction of the force so important to know?  These variables help to determine the length of the moment arm (moment) of the resistance at each joint.  If you don't know the moment, you cannot determine the amount of torque that is occurring at the joint and, subsequently, you are unable to calculate the joint forces as well as the amount of force that has to be generated by the muscles in order to move that load.

The point that was never discussed in any of the four articles is that there are significantly different moments created to the ankles, knees, hips, and spinal levels, along with every other joint in the body that rests below the placement of the load, when comparing the front squat and back squat, not only at the bottom position, but at every position between the bottom and the top of the movement.

And that, in my opinion, is one of the most important factors that has to be considered when determining whether to prescribe front squats or back squats, or any exercise for that matter, to an individual.
Your Body.  Your Training.

Get big or die tryin'.

Charlie Cates, MATs, CSCS
Self Made_®, Owner and Founder

Charlie Cates is a Muscle Activation Techniques _® specialist and a strength and conditioning specialist.  He is the owner and founder of Self Made_® (http://selfmadefitness.com/) in Chicago, IL.  He has worked with competitive and everyday athletes of all ages and ability levels, from 9-year-old kids to NFL MVP’s.  He can be reached via e-mail at charlie@selfmadefitness.com.
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