- Jun 25, 2006
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by Charles Poliquin
The squat is one of the best exercises for athletes and the general population. The different squat variations can improve structural balance in the body, build strength, increase vertical jump, increase running speed and power, and build muscle and bones. This article will review the new research on how to get the greatest training results from squats and briefly address some of the misconceptions surrounding the squat.
#1: Don’t Be Afraid To Squat ALL THE WAY DOWN
A common misconception is that full squats in which you go all the way down below parallel to a point where the hamstring covers the calf should be avoided because they are “bad for the knees.” This bogus “rule” comes in part from the concern that it is bad for the knee to travel forward over the toes, as they do during full squats. Did you realize that the knee travels forward over the toes every time you go up and down the stairs?
Plus, research shows that this forward movement does not hurt the knees or increase knee laxity. For example, an 8-week study that compared parallel with below parallel squats showed no difference in knee laxity, and elite weightlifters who regularly deep squat with near maximal loads have less knee laxity than controls.
Take Away: Training full squats in which you go all the way down can improve functional mobility and help you avoid pain or dysfunction associated with movements in which the knee travels forward, such as when you go up and down the stairs.
#2: Train Full Squats For Optimal Lower Body Strength
The fear about full squats being bad for the knees also comes from the concern that there is an increase in shear force on the knee in the lowest part of the squat. Now, it is true that the peak force at the knee is progressively greater as squat depth increases from a half squat to parallel to the deep squat.
Shear force also increases as you increase the load lifted from a body weight squat to a loaded squat that is 50 percent of the 1RM to a heavy load that is 85 percent of the 1RM, and so forth. However, the increase is not linear. Rather, the shear force increases most when you go from body weight to a 50 percent of the 1RM load. The rate of increase then levels off and is very gradual up to maximal loads.
In addition, one study found that the greatest shear force on the knee is at the start of the squat when the lifter initiates the bend of the knee. The authors note that an analysis performed on cadavers showed that the pressure on the knee decreases as the knee flexion angle increases from parallel to 120° (the bottom part of the squat).
Doing a parallel squat in which trainees made sure their knees did not travel forward past the toes was found to put much greater force on the hip joint than when the full squat was trained. Restricting the forward motion of the knee altered the trainees’ center of mass, increasing the force at the hip and the proportion of load on the lower back.
Take Away: What all this amounts to is that there is greater force at the knee as you increase depth and as you increase load, but the force is not something to be scared of. Restricting the forward motion of the knees during the squat is an unnatural movement pattern that can increase the force at the hip joint, displace the center of mass, reduce stability, and put greater stress on the lumbar spine. This needs to be avoided, especially when heavy loads are lifted.
When you run, jump, and lift weights you increase the force on the joints, and if your muscles aren’t structurally balanced you are at risk of injury. Therefore, just as you wouldn’t avoid training with weight because it increases force at the knee, you shouldn’t avoid going all the way down in the squat.
#3: Do Full Squats To Optimally Build Muscle Mass & Strength
Research suggests that the hamstrings, glutes, quads, and calves are all maximally trained as squat depth increases. Although there is not yet a definitive consensus on this from the research, a biomechanical analysis suggests that the best way to train the gluteus and hamstrings of the posterior chain is with a heavy load (over 80 percent of the 1RM) and to squat below parallel.
As both load and depth increased, the posterior chain performed more work. For the quadriceps, squat depth was most important. The load lifted didn’t influence the contribution of the quads, whereas for the calves the greatest muscular effort was with the heaviest 90 percent load when trainees squatted all the way down.
Electromyographic (EMG) studies that test muscle activation aren’t very helpful because there are no EMG studies that compare muscle activation using a standardized load, and none that compare the deep and parallel squat. However, in a review of the EMG data we do have, the authors write that “partial squats will result in reduced muscle activation of the prime movers, and therefore arguably produce an inferior training effect in comparison to parallel or full squats.”
The real evidence of the superiority of full squats is with a study that found that in experienced recreational trainees, deep squats are more effective for increasing jump height than partials. In addition, the trunk muscles of the lower back and abdominal area are maximally trained with full squat variations and heavy loads.
Take Away: Full squats are a super bang for your buck exercise because they will provide near optimal stimulus to the entire posterior chain, the quadriceps, and the trunk muscles. Use them as a primary training lift to increase jump height.
#4: Train Unilateral Squats For Structural Balance: Build a Stronger, More Powerful Back Squat
The bilateral back squat may be the “king” of all exercises, however, unilateral squats are just as important as a fundamental lift. One of the principal outcomes of squat related studies this past year was a reinforcement of the value of unilateral squatting:
• For example, unilateral evaluations are necessary to identify structural imbalances—the bilateral overhead squat won’t reveal all imbalances, especially to an evaluator without extensive experience.
• Bilateral asymmetry is extremely common among competitive athletes and the general population. It impairs strength and power development in compound lifts like the back squat because it results in uneven force output and excessive bar horizontal displacement. Single-leg training with split squats and step-up variations can build structural balance and promote bilateral symmetry for a better squat.
• Limited range of motion in the ankles and hips can render a bilateral back squat useless for training purposes or even dangerous because it puts the trainee at risk of injury. A recent study showed that poor ankle mobility altered muscle activation in the lower body, leading to greater activity of the soleus in the calf and less activity in the vastus medialis obliquus (VMO). This increased the chance that an athlete’s knee will cave inward during the squat—a very concerning outcome since weakness in the VMO is very common and it will greatly increase risk of injury.
Unilateral lifts such as the deep split squat in which the knee comes forward over the toes will promote ankle and hip range of motion, while promoting structural balance.
To solve range of motion issues in lower body joints, do soft tissue work and mobility exercises. Use modifications like squatting on a wedge board that elevates the heels and increases range of motion of the ankle if necessary.
Take Away: Every trainee should go through a structural balance assessment before training the bilateral squat. Nearly every trainee will require at least some unilateral squatting to promote balance, avoid asymmetry, and promote proper movement patterns.
#5: Use Squat Variations To Overcome Plateaus
Once structural balance and base levels of strength are developed, you can use squat variations to continually make gains and overcome plateaus. For example, a heavy full-range front squat is excellent for training vertical acceleration, and it will optimally activate the abdominals, the quads, and the lower back.
The front squat also requires superior technique, and it keeps you honest if you are lifting a heavy load since you will likely drop the bar or get injured if you cheat. If there is legitimate concern about the compressive force on the knee from full-range back squats, deep front squats can be used since they place less force on the knee. Front squats also require flexibility in the hip, ankle, wrist, and shoulder joints, making them an incentive to work on range of motion, and the arm position mimics the catch position of the clean.
Partial-range squats can occasionally be trained by advanced lifters and athletes to overcome a plateau, but never at the exclusion of deep squats. For instance a study that used trained athletes showed that power and force output were greatest when athletes did partial squats using an 83 percent of the 1RM load. Velocity was greatest with full squats using a lighter 67 percent load. This provides a classic example of how variations can be used for athletes to train speed and a quick first step for short sprints (do full range squats), or power and force for contact sports (do heavy partials).
Take Away: A commitment to full-range training is critical. Manipulate variables such as tempo, intensity, load, bar placement, and type of contraction using a full range first. For advanced trainees, specificity and partial-range lifts may allow you to overcome plateaus, but you must program them with strategic precision.
References:
Lorenzetti, S., Bulay, T., et al. Comparison of the Angles and Corresponding Moment in the Knee and Hip during Restricted and Unrestricted Squats. Journal of Strength and Conditioning Research. 2012. 26(10), 2829.
Cotter, J., et al. Knee Joint Kinetics in Relation to Commonly Prescribed Squat Loads and Depths. Journal of Strength and Conditioning Research. 2012. Published Ahead of Print.
Marcum, E., Bell, D., et al. Effect of Limiting Ankle-Dorsiflexion Range of Motion on Lower Extremity Kinematics and Muscle-Activation Patterns During a Squat. Journal of Sport Rehabilitation. 2012. 21(2), 144-150.
Ronei, P., Gomes, N., et al. Effect of Range of Motion on Muscle Strength and Thickness. Journal of Strength and Conditioning Research. 2012. 26(8), 2140-2145.
McBride, J., Skinner, J., et al. Comparison of Kinetic Variables and Muscle Activity During a Squat Vs. A Box Squat. Journal of Strength and Conditioning Research. 2010. 24(12), 3195-3199.
Bryanton, M., Kennedy, M., et al. Effect of Squat Depth and Barbell Load on Relative Muscular Effort in Squatting. Journal of Strength and Conditioning Research. 2012. 26(190, 2820-2828.
Comfort, P., Haigh, A., et al. Are Changes in Maximal squat Strength During Preseason Training Reflected in Changes in Sprint Performance in Rugby League Players? Journal of Strength and Conditioning Research. 2012. 26(3), 772-776.
Simao, A., Avelar, N., et al. Functional Performance and Inflammatory Cytokines After Squat Exercises and Whole-Body Vibration in Elderly Individuals with Knee Osteoarthritis. Archives of Physical Medicine and Rehabilitation. April 2012. 93(10), 1692-1700.
Matuschek, C., Schmidtbleicher, D. Influence of Squatting depth on Jumping Performance. Journal of Strength and Conditioning Research. 2012. 26(12), 3243-3261.
Clark, D., Lambert, M., et al. Muscle Activation in the Loaded Free Barbell Squat: A Brief Review. Journal of Strength and Conditioning Research. 2012. 26(4), 1169-1178.
Bird, Stephen and Casey, Sean. Exploring the Front Squat. Strength and Conditioning Journal. February 2012. Published Ahead of Print.
Cissik, John. Coaching the Front Squat. Strength and Conditioning Journal. October 2000. 22(5), 7-12.
Shinkle, J., Nesser, T., et al. Effect of Core Strength on the Measure of Power in the Extremities. Journal of Strength and Conditioning Research. January 2012. 26(2), 373-380.
Okada, T., Huxel. K., Nesser, T. Relationship Between Core Stability, Functional Movement, and Performance. Journal of Strength and Conditioning Research. January 2011. 25(1), 252-261.
Sharrock, C., Cropper, J., Mostad, J., Johnson, M., Malone, T. A Pilot Study of Core Stability and Athletic Performance: Is There a Relationship? International Journal of Sports Physical Therapy. June 2011. 6(2), 63-74
Keiner, M., Sander, A., et al. Trainability of Adolescents and Children in the Back and Front Squat. Journal of Strength and Conditioning Research. 2012. Published Ahead of Print.
The squat is one of the best exercises for athletes and the general population. The different squat variations can improve structural balance in the body, build strength, increase vertical jump, increase running speed and power, and build muscle and bones. This article will review the new research on how to get the greatest training results from squats and briefly address some of the misconceptions surrounding the squat.
#1: Don’t Be Afraid To Squat ALL THE WAY DOWN
A common misconception is that full squats in which you go all the way down below parallel to a point where the hamstring covers the calf should be avoided because they are “bad for the knees.” This bogus “rule” comes in part from the concern that it is bad for the knee to travel forward over the toes, as they do during full squats. Did you realize that the knee travels forward over the toes every time you go up and down the stairs?
Plus, research shows that this forward movement does not hurt the knees or increase knee laxity. For example, an 8-week study that compared parallel with below parallel squats showed no difference in knee laxity, and elite weightlifters who regularly deep squat with near maximal loads have less knee laxity than controls.
Take Away: Training full squats in which you go all the way down can improve functional mobility and help you avoid pain or dysfunction associated with movements in which the knee travels forward, such as when you go up and down the stairs.
#2: Train Full Squats For Optimal Lower Body Strength
The fear about full squats being bad for the knees also comes from the concern that there is an increase in shear force on the knee in the lowest part of the squat. Now, it is true that the peak force at the knee is progressively greater as squat depth increases from a half squat to parallel to the deep squat.
Shear force also increases as you increase the load lifted from a body weight squat to a loaded squat that is 50 percent of the 1RM to a heavy load that is 85 percent of the 1RM, and so forth. However, the increase is not linear. Rather, the shear force increases most when you go from body weight to a 50 percent of the 1RM load. The rate of increase then levels off and is very gradual up to maximal loads.
In addition, one study found that the greatest shear force on the knee is at the start of the squat when the lifter initiates the bend of the knee. The authors note that an analysis performed on cadavers showed that the pressure on the knee decreases as the knee flexion angle increases from parallel to 120° (the bottom part of the squat).
Doing a parallel squat in which trainees made sure their knees did not travel forward past the toes was found to put much greater force on the hip joint than when the full squat was trained. Restricting the forward motion of the knee altered the trainees’ center of mass, increasing the force at the hip and the proportion of load on the lower back.
Take Away: What all this amounts to is that there is greater force at the knee as you increase depth and as you increase load, but the force is not something to be scared of. Restricting the forward motion of the knees during the squat is an unnatural movement pattern that can increase the force at the hip joint, displace the center of mass, reduce stability, and put greater stress on the lumbar spine. This needs to be avoided, especially when heavy loads are lifted.
When you run, jump, and lift weights you increase the force on the joints, and if your muscles aren’t structurally balanced you are at risk of injury. Therefore, just as you wouldn’t avoid training with weight because it increases force at the knee, you shouldn’t avoid going all the way down in the squat.
#3: Do Full Squats To Optimally Build Muscle Mass & Strength
Research suggests that the hamstrings, glutes, quads, and calves are all maximally trained as squat depth increases. Although there is not yet a definitive consensus on this from the research, a biomechanical analysis suggests that the best way to train the gluteus and hamstrings of the posterior chain is with a heavy load (over 80 percent of the 1RM) and to squat below parallel.
As both load and depth increased, the posterior chain performed more work. For the quadriceps, squat depth was most important. The load lifted didn’t influence the contribution of the quads, whereas for the calves the greatest muscular effort was with the heaviest 90 percent load when trainees squatted all the way down.
Electromyographic (EMG) studies that test muscle activation aren’t very helpful because there are no EMG studies that compare muscle activation using a standardized load, and none that compare the deep and parallel squat. However, in a review of the EMG data we do have, the authors write that “partial squats will result in reduced muscle activation of the prime movers, and therefore arguably produce an inferior training effect in comparison to parallel or full squats.”
The real evidence of the superiority of full squats is with a study that found that in experienced recreational trainees, deep squats are more effective for increasing jump height than partials. In addition, the trunk muscles of the lower back and abdominal area are maximally trained with full squat variations and heavy loads.
Take Away: Full squats are a super bang for your buck exercise because they will provide near optimal stimulus to the entire posterior chain, the quadriceps, and the trunk muscles. Use them as a primary training lift to increase jump height.
#4: Train Unilateral Squats For Structural Balance: Build a Stronger, More Powerful Back Squat
The bilateral back squat may be the “king” of all exercises, however, unilateral squats are just as important as a fundamental lift. One of the principal outcomes of squat related studies this past year was a reinforcement of the value of unilateral squatting:
• For example, unilateral evaluations are necessary to identify structural imbalances—the bilateral overhead squat won’t reveal all imbalances, especially to an evaluator without extensive experience.
• Bilateral asymmetry is extremely common among competitive athletes and the general population. It impairs strength and power development in compound lifts like the back squat because it results in uneven force output and excessive bar horizontal displacement. Single-leg training with split squats and step-up variations can build structural balance and promote bilateral symmetry for a better squat.
• Limited range of motion in the ankles and hips can render a bilateral back squat useless for training purposes or even dangerous because it puts the trainee at risk of injury. A recent study showed that poor ankle mobility altered muscle activation in the lower body, leading to greater activity of the soleus in the calf and less activity in the vastus medialis obliquus (VMO). This increased the chance that an athlete’s knee will cave inward during the squat—a very concerning outcome since weakness in the VMO is very common and it will greatly increase risk of injury.
Unilateral lifts such as the deep split squat in which the knee comes forward over the toes will promote ankle and hip range of motion, while promoting structural balance.
To solve range of motion issues in lower body joints, do soft tissue work and mobility exercises. Use modifications like squatting on a wedge board that elevates the heels and increases range of motion of the ankle if necessary.
Take Away: Every trainee should go through a structural balance assessment before training the bilateral squat. Nearly every trainee will require at least some unilateral squatting to promote balance, avoid asymmetry, and promote proper movement patterns.
#5: Use Squat Variations To Overcome Plateaus
Once structural balance and base levels of strength are developed, you can use squat variations to continually make gains and overcome plateaus. For example, a heavy full-range front squat is excellent for training vertical acceleration, and it will optimally activate the abdominals, the quads, and the lower back.
The front squat also requires superior technique, and it keeps you honest if you are lifting a heavy load since you will likely drop the bar or get injured if you cheat. If there is legitimate concern about the compressive force on the knee from full-range back squats, deep front squats can be used since they place less force on the knee. Front squats also require flexibility in the hip, ankle, wrist, and shoulder joints, making them an incentive to work on range of motion, and the arm position mimics the catch position of the clean.
Partial-range squats can occasionally be trained by advanced lifters and athletes to overcome a plateau, but never at the exclusion of deep squats. For instance a study that used trained athletes showed that power and force output were greatest when athletes did partial squats using an 83 percent of the 1RM load. Velocity was greatest with full squats using a lighter 67 percent load. This provides a classic example of how variations can be used for athletes to train speed and a quick first step for short sprints (do full range squats), or power and force for contact sports (do heavy partials).
Take Away: A commitment to full-range training is critical. Manipulate variables such as tempo, intensity, load, bar placement, and type of contraction using a full range first. For advanced trainees, specificity and partial-range lifts may allow you to overcome plateaus, but you must program them with strategic precision.
References:
Lorenzetti, S., Bulay, T., et al. Comparison of the Angles and Corresponding Moment in the Knee and Hip during Restricted and Unrestricted Squats. Journal of Strength and Conditioning Research. 2012. 26(10), 2829.
Cotter, J., et al. Knee Joint Kinetics in Relation to Commonly Prescribed Squat Loads and Depths. Journal of Strength and Conditioning Research. 2012. Published Ahead of Print.
Marcum, E., Bell, D., et al. Effect of Limiting Ankle-Dorsiflexion Range of Motion on Lower Extremity Kinematics and Muscle-Activation Patterns During a Squat. Journal of Sport Rehabilitation. 2012. 21(2), 144-150.
Ronei, P., Gomes, N., et al. Effect of Range of Motion on Muscle Strength and Thickness. Journal of Strength and Conditioning Research. 2012. 26(8), 2140-2145.
McBride, J., Skinner, J., et al. Comparison of Kinetic Variables and Muscle Activity During a Squat Vs. A Box Squat. Journal of Strength and Conditioning Research. 2010. 24(12), 3195-3199.
Bryanton, M., Kennedy, M., et al. Effect of Squat Depth and Barbell Load on Relative Muscular Effort in Squatting. Journal of Strength and Conditioning Research. 2012. 26(190, 2820-2828.
Comfort, P., Haigh, A., et al. Are Changes in Maximal squat Strength During Preseason Training Reflected in Changes in Sprint Performance in Rugby League Players? Journal of Strength and Conditioning Research. 2012. 26(3), 772-776.
Simao, A., Avelar, N., et al. Functional Performance and Inflammatory Cytokines After Squat Exercises and Whole-Body Vibration in Elderly Individuals with Knee Osteoarthritis. Archives of Physical Medicine and Rehabilitation. April 2012. 93(10), 1692-1700.
Matuschek, C., Schmidtbleicher, D. Influence of Squatting depth on Jumping Performance. Journal of Strength and Conditioning Research. 2012. 26(12), 3243-3261.
Clark, D., Lambert, M., et al. Muscle Activation in the Loaded Free Barbell Squat: A Brief Review. Journal of Strength and Conditioning Research. 2012. 26(4), 1169-1178.
Bird, Stephen and Casey, Sean. Exploring the Front Squat. Strength and Conditioning Journal. February 2012. Published Ahead of Print.
Cissik, John. Coaching the Front Squat. Strength and Conditioning Journal. October 2000. 22(5), 7-12.
Shinkle, J., Nesser, T., et al. Effect of Core Strength on the Measure of Power in the Extremities. Journal of Strength and Conditioning Research. January 2012. 26(2), 373-380.
Okada, T., Huxel. K., Nesser, T. Relationship Between Core Stability, Functional Movement, and Performance. Journal of Strength and Conditioning Research. January 2011. 25(1), 252-261.
Sharrock, C., Cropper, J., Mostad, J., Johnson, M., Malone, T. A Pilot Study of Core Stability and Athletic Performance: Is There a Relationship? International Journal of Sports Physical Therapy. June 2011. 6(2), 63-74
Keiner, M., Sander, A., et al. Trainability of Adolescents and Children in the Back and Front Squat. Journal of Strength and Conditioning Research. 2012. Published Ahead of Print.