Whether you want more booty or quads, being a mechanic can alter your squat perception.
One of the most misunderstood and abused exercises that I see in the gym is the squat. While being an amazing total body exercise (placing emphasis in the lower body of course) technique can make it one of the worst, with serious consequences. In this first part I’m going to show you how different body positions can alter things.
3 main variations of the squat:
High bar squat, low bar squat and the front squat. Most people when they think about squatting think quads. With a little knowledge of biomechanics though, you will realise how the above variations place emphasis on different musculature! I’ll try not to bore you with too much science. Here goes:
In any given exercise there are points of rotation (POR) or fulcrums. In our discussion the ones of interest are the hip and the knee joint. When you come up from the bottom position of a squat, you perform extension at both of these joints (POR). Hip extensors are the glutes and hamstrings aka the “posterior chain”. Knee extensors are the quadriceps. In order to do that, you need to overcome some external resistance be that your bodyweight or some form of extra resistance (barbell).
A moment arm is the distance between a POR (hips, knee) and the point at which the rotational force is applied (in this case the barbell or to be precise gravity acting on the barbell), measured at 90 degrees from the point of force application (Fig.1)
The moment force is expressed in M= F (force applied to the bar) x d (length of moment arm). The magnitude of M tells us how much the object (knee, hips) is striving to turn. Shit that was boring! Bear with me….
From the equation we realize that the greater the distance of the rotational force from the fulcrum the greater the moment arm (that’s what we want!) Just imagine having a small ass wrench opposed to a big ol’ one to try and screw a bolt. I’ll take the big one any day!!
For muscle to contract, crossbridges must be formed between the myofilaments. Crossbridge formation is prevented either by excessive lengthening or shortening of the sarcomere. Maximum tension and therefore force can be achieved when muscle is slightly lengthened or about 120% of its resting length. In layman’s terms you need to slightly stretch a muscle that you want to maximally activate.
I can hear you snoring already. Ok, ok I’ll shut up. Trust me, this is more info than you’ll ever need! That’s all for your plumbing course…err…. biomechanics I meant!
We got wrenches we got bolts! Let’s put theory into practice and make something happen!
As mentioned earlier we have 3 squat variations:
The name refers to the fact that the bar sits low on the back. How low? The lowest safest position is right below the spine of the scapula (Pic 1). Any lower than that and the bar would be difficult to handle with appreciable weight loaded on it. So let’s apply the aforementioned knowledge on this type of squat. It is obvious that in order not to fall backward and to keep our base of support over the midfoot (that’s were it should always be when squatting) you will need to lean more forward. What this does:
- The back can be more horizontal relative to the floor, which means that there is a better lever relative to the hips, so the posterior chain does the work. Think hamstrings and glutes. Back gets a beating too, especially the lower part.
- The hamstrings are a biarticular (crosses two joints) muscle, which cross the hips and the knees. On the bottom position of the squat we can see that they are shortened at the knee joint. Therefore, in order to maximize hamstring involvement we need to at least stretch them at the hip end. Bending more forward accomplishes just that. Glutes get a better stretch as well.
High bar is the style that you will see more often in the gym. For a novice it feels a little more natural and it’s not as tricky in the execution. In this type of squat the bar sits higher on the upper traps (pic. 2). In order for the lifter to balance and not fall face forward, (as much as it would be tempting to watch) he/she is forced to stay more upright. The result:
- The back is more vertical; therefore the lever is more advantageous to the knee. This type of squat places more emphasis in the anterior chain (or the quads).
- Because of the fact that the athlete stays more upright, the knee angle is more closed therefore we get a slight stretch on the quads, whereas the hip angle is more open therefore less activation of the hamstrings and glutes.
The front squat puts the lifter in an even more upright position than the other two variations. What this does, it lessens the torque (forward lean), compression (high spinal loads) and flexion. A recent study (5) also shows that the front squat works the quads harder with less stress on the knees. It is also shown to be more effective at activating the vastus lateralis and the rectus femoris. An excellent variation is the goblet squat, which I am going to analyze on the second instalment of the squat series.
- Back is as vertical as possible to compensate for the weight that rests in front of the body so the base of support can be kept over midfoot. That makes the moment arm of the knee more favorable.
- Knee angle is even more closed and hip angle remains relatively open. This activates the quads maximally.
But wait. What do I do?
One variation does not cancel the other. It all depends on:
- Who your client is
- His/her needs
- What limitations he/she has (joint health, mobility, muscle imbalances, technical proficiency)
- Goals (sports, general fitness etc)
Powerlifters mainly use low bar squats. It increases forward leaning, puts more emphasis on the posterior chain and a greater stress on the back muscles. Glutes are the most powerful muscle in the body (hint: want more booty? Stick with low bar!). This type of squat is probably going to allow you to push the most weight.
Actually in order of difficulty (not technical necessarily) it goes like this: Low bar, high bar, front (easier to harder). If your goal is physic enhancement or transference to Oly lifts I would stick to the high bar and especially front squats.
My advice? Unless your client is an athlete of a specific sport that would benefit strictly from the use of one, I would use them all to activate as much muscle fibers as possible while taking the following under consideration:
For a client that has poor glute and/or posterior chain activation I would probably stick with a low bar squat. On the other hand, if low back pain was a problem and technique was an issue I would stay away from them (low bar). As mentioned earlier biomechanical analysis indicates that the front squat places less compressive forces on the knees. Therefore an athlete/client with knee problems/sensitivity should probably stick to a more upright squat.
Coming up: Squat myths and how to solve squat technique problems. See you soon!
1. Baechle TR and Earle R. Essentials of Strength and Conditioning (2nd ed). Champaign: Human Kinetics, 2000. Print.
2. Rippetoe, Mark and Stef Bradford. Starting Strength Basic Barbell Training 3rd Edition. Wichita Falls, Texas: The Aasgaard Company, 2011. Kindle.
3. Wirhed, Rolf. Athletic Ability and the Anatomy of Motion. Orebro, Sweden: Harpoon Publications AB, 1984. Print.
4. Thompson, Walter R. ACSM’S Resources for the Personal Trainer. Baltimore, MD: Lippincott Williams & Wilkings, 2010. Print.
5. Gullett JC, Tillman MD, Gutierrez GM, Chow JW. A biomechanical comparison of back and front squats in healthy trained individuals. Journal of Strength and Conditioning Research. 2009 Jan;23(1):284-92.
6. Boyle, Michael. Advances in Functional Training: Training techniques for Coaches, Personal Trainers and Athletes. Santa Cruz, California: On Target Publications, December 2011. Kindle.