Squats have long been claimed to be one of the best exercises for throwing strength and mass on someone. Unfortunately they’ve also gotten a bad wrap from people who have gotten hurt while performing them incorrectly. In this article, we examine a few basic principles of the squat motion and what you can do to eliminate potential weak points that may be limiting your performance.

The Bad Rap of Squats

Figure 1. The Almighty Squat. Image Source³

In today’s world, I still hear too many “fitness experts” make claims such as “squats are bad for the knees”, or the ridiculous claim that if you “roll your knee too far forward, you will BLOW OUT YOUR PATELLA TENDON”. Even better yet are statements such as “Individual should not squat. The risk-reward ratio is just too high. If they want to work their legs, just put them on a leg press or Smith machine.” Are you serious? Are the individuals making these preposterous statements joking ? Have they not read Squat Mechanics or Smith vs. Free Weight Squats?

With that being said, let’s examine a few basic principles of the squat motion.

The Motion – Weight Distributions

Throughout the squat, the bar has to remain over the mid-foot. In other words, throughout any part of the movement, one should be able to drop a vertical line straight down from the bar and it should land directly over the middle of his/her foot. Deviations to this ideal placement occur if one’s knees move too far forward or their back is too flat. When this occurs, the weight shifts towards the front of the athlete’s foot, producing a more acute knee angle which increases the torque placed on the knee joint. Furthermore, this has a detrimental effect on hip extension as it decreases the hamstrings ability to contribute to hip extension. Why does this happen you ask? Simple, any time the knee angle closes, the hamstrings have shortened from the distal end. As a result, they have been removed/contribute less power to the movement. This is analogous to a rubber band; in a stretched (ie-lengthened) position they snap hard. Yet, if not fully stretched (ie-shortened), their snap is not nearly as forceful.

On the flip side of the equation, allowing the weight to shift behind the mid-foot is not ideal either. You often hear coaches talk about “loading the heals” during the squat movement. However, this statement is not truly accurate and often leads to problems; especially in beginning squatters who interpret it as “load ALL the weight” on your heels. In trying to “load the heals”, they start to fall back, despite the fact that stance and bar position may be correct. Thus, it’s important for individuals to distribute the weight across the entire foot, with the bar centered over the middle of it.

Troublesome Weak Points Along the Posterior Chain

Many well known coaches and trainers have stated that the back tends to be the weakest link in the posterior chain and I tend to agree with this position. For example, let’s look at the role of the erector spinae muscles. They serve to lock the pelvis and lower back together into a rigid structure, protect the vertebral column from movement under load and prevent the intervertebral column from excessive damage. As squat depth increases, and the torso assumes a more forward tilt, the bottom of the pelvis, locked into the rigid spine, tilts away from the back of the knee.

Next, I’d like to discuss the hamstring which originates from the ischial tuberosity (bottom posterior side of pelvis just under the glutes – aka “butt” muscles) and inserts on the posterior side of the tibia. While descending into the squat position, the hamstrings become eccentrically loaded. As I’m sure many of you know, eccentric movements refer to the ability of a muscle to be stretched WHILE it’s contracting. If any of those qualities are “subpar”, problems will result. Let’s first examine the importance of hamstring flexibility — If hamstring extensibility is lacking, they will exert tension on the bottom of the ischium, potentially pulling the pelvis out of its locked position. This breaks muscular tension which leads to a “rounding” of the back.

Now let’s examine what will happen if the strength part of an eccentrically loaded hamstring is compromise — With their insertion on the posterior side of the tibia, the hamstrings provide posterior tension, limiting forward knee movement. This tension heightens (or at least should) with increasing squat depth as the other attachment points on the pelvis tilts away. If the tension is inadequate to keep the knees from sliding excessively forward during the descent, performance will be compromised and/or you’ll have anterior hip pain. (I stress the word excessively because there will be some forward movement of the knee during the eccentric portion of the lift which is completely natural¹).

Figure 2. The Anterior Hip Flexors. ASIS = Anterior Superior Iliac Spine, TFL = Tensor Fascia Lata. Picture has been modified from it’s original source⁵.

To understand why this happens, once again we have to look at a little functional anatomy (see Figure 3). When the knees travel forward during the descent, tension is placed on the rectus femoris, sartorius, and tensor fascia latae (TFL). The primary function of these muscles is knee extension while squatting. However, most people commonly forget that they also cross the hip joint, inserting around the anterior superior iliac spine (ASIS). [For reference, the superior iliac spine is the bony point on the upper front side of the pelvis]. Thus, these muscles have the potential to extend the knee AND flex the hip. Obviously we want the former (knee extension) and not the latter (hip flexion) of those actions to occur while squatting! Taking this into account, let’s look at what can occur at the hip joint as a result of excessive forward knee motion:

Excessive forward knee motion —> Increased Muscle Tension —> Increased Tension On ASIS (pull on hip can be pretty tremendous) —> Tendonitis and Anterior Hip Pain.

It’s for the reason stated above that some people feel tension or perhaps an uncomfortable pain in the hip flexor area while/after squatting.

Posterior Chain Exercises

If the posterior chain happens to be your weakest link, then simply do exercises that strengthen these areas. Besides the traditional core exercises (glute bridges, pillars, etc) , the following are excellent assistance exercises for enhancing the posterior chain and will be of great assistance when rotated into your training program:

• Stiff Leg Deadlifts (SLDL’s) – Heavy dumbbell or barbell
• Glute- Ham Raise and reverse Glute-Ham Raise
• Good Mornings – Great exercise that is more specific to squats (and deadlifts for that matter) vs. the first 2 exercises mentioned

At the Bottom – Squat Depth

Now that we’ve got the weight properly distributed on your foot, your posterior chain issues covered, let’s shift gears and look squat depth… Deep squats MAY increase susceptibility to patella-femoral degeneration given the high amount of patella-femoral stress that arises from contact of the underside of the patella (knee cap) with the articulating aspect of the femur during high knee flexion². However, there is little evidence to show a cause-effect relationship implicating an increased squat depth with injury to these structures in healthy subjects. Squat depth has been shown to have a significant effect on muscular development at the hip and knee joints, particularly with respect to the gluteus maximus. Research from Caterisano et al. demonstrated that while average muscle activity of the GM was not significantly different in both the partial squat (16.92 ± 8.78%) and parallel squat (28.00 ± 10.29%), it increased significantly during the full squat (35.47 ± 1.45%)³. Similar results were shown for peak values, which displayed significantly greater activity during performance of the full squat as compared to lesser squat depths.

Finish strong – Don’t “Raise the Chest” or Turn it Into a Good-Morning

We’ve covered everything in the squat motion now except the final motion – Rising from bottom position of the squat, which is commonly referred to as “rising from the hole”. Unfortunately, when completing this motion, most people “drive their chest up”. Driving the chest, instead of the hips, destroys the power generated by the hamstring & glute maximus right in the middle of the squat. Likewise adductor power is likely compromised as well.

Upon “rising from the hole”, many individuals will turn the concentric phase of the full squat into a good morning. Maintaining torso tightness (keeping the chest up) but NOT RAISING THE CHEST will assist those in this situation. Through experience however, when heavier loads are used, “Hip drive” becomes less pronounced, and can possibly cause a more forward tilt on the concentric phase. Therefore, it is of critically importance that individuals are anatomically and kinesthetically aware of what they are doing.

On a final note… Want to push heavier weights? Ditch the bodybuilding stance!

When one is using a “bodybuilding style” stance, which is characterized by it’s narrow stance and a greater forward knee movement, hamstring activity is minimized, from both a biomechanical and possibly physiologically (i.e. motor unit recruitment) perspective. As previously discussed, any time the knee angle closes, the hamstrings contribution to the movement is compromised vs. a wider stance with less forward knee movement. Moreover, it’s very difficult for everyday people, who typically lack proper flexibility, to perform deep squats with a narrow stance. Thus the hamstring are never fully engaged. Adductor activity is also reduced in a narrow stance due to being in a “shortened” position when squatting in a traditional bodybuilder style.

Bottom Line

One of the reasons many people don’t squat is that it’s hard. It’s very difficult to balance hundreds of pounds of one’s back. However, in the realm of performance, or regardless of one’s goal’s, the hard things give individuals the best results. Make sure you’ve ironed out the problems discussed above, stick to the basics, and simply SQUAT!

Now that you’ve finished Squatology 101, be sure to check out Squatology 202 where we discuss the “How’s” and “Why’s” of including various squat variations into your training routine.

References

¹ Fry AC, Smith JC, Schilling BK. Effect of knee position on hip and knee torques during the barbell squat. J Strength Cond Res. 2003 Nov;17(4):629-33.

² Caterisano A, Moss RF, Pellinger TK, Woodruff K, Lewis VC, Booth W, and Khadra T. The effect of back squat depth on the EMG activity of 4 superficial hip and thigh muscles. Journal of Strength and Conditioning Research. 16(3):428 – 432. 2002

³ Escamilla RF, Fleisig GS, Zheng N, Lander JE, Barrentine SW, Andrews JR, Bergemann BW, and Moorman CT. Effects of technique variationson knee biomechanics during the squat and leg press. Medicine and Science in Sports and Exercise. 33:1,552 – 1,566. 2001.

⁴ Image created by Everkinetic and is under creative commons licensure. Accessed July 23, 2011 from: http://everkinetic.com/exercise/wide-stance-squat

⁵ Image under the public domain and accessed July 23, 2011 from: http://en.wikipedia.org/wiki/File:Gray430.png