The following is an excerpt from ‘Starting Strength’ by Mark Rippetoe and Len Kilgore. It breaks down in detail, why the squat should always be performed to full depth (where injuries do not prevent it) and describes the stresses on or around the knee and hips.
The full squat is the preferred lower body exercise for safety as well as athletic strength. The squat, when performed correctly, is not only the safest leg exercise for the knees, it produces a more stable knee than any other leg exercise. The important part of the last statement is the “when performed correctly” qualifier. Correctly is deep, with hips dropping below level with the top of the patella. Correctly is full range of motion.
Any squat that is not deep is a partial squat, and partial squats stress the knee and the quadriceps without stressing the glutes, the adductors, and the hamstrings. The hamstrings, groin muscles, and glutes perform their function in the squat when the hips are stretched to the point of full flexion, where they get tight — the deep squat position.
The hamstring muscles, attached to the tibia and to the ischial tuberosity of the pelvis, and the adductors, attached between the medial femur and various points on the medial pelvis, reach a full stretch at the very bottom of the squat, where the pelvis tilts forward with the torso, stretching the ends of the muscles apart. At this stretched position they provide a slight rebound out of the bottom, which will look like a “bounce,” and which you will learn more about later. The tension of the stretch pulls the tibia backwards, the posterior direction, balancing the forward-pulling force produced by the quadriceps, which pull from the front. The hamstrings finish their work, with help from the adductors and glutes, by straightening out, or “extending,” the hip.
Muscular actions on the knee. The anterior force provided by the quadriceps is balanced by the posterior force provided by the hamstrings in the deep squat position. The depth is the key: partial (high) squats are predominately quadriceps/anterior and lack balance.
In a partial squat, which fails to provide a full stretch for the hamstrings, most of the force against the tibia is upward and forward, from the quadriceps and their attachment to the front of the tibia below the knee. This produces an anterior shear, a forward-directed sliding force, on the knee, with the tibia being pulled forward from the patellar tendon and without a balancing pull from the opposing hamstrings. This shearing force — and the resulting unbalanced strain on the prepatellar area — may be the biggest problem with partial squats. Many spectacular doses of tendonitis have been produced this way, with “squats” getting the blame.
The variation in squat depth often seen in the gym. A Quarter-squat, B Half-squat, C A position often confused with parallel, where the undersurface of the thigh is parallel to the ground. D A parallel squat according to the criteria established.
The hamstrings benefit from their involvement in the full squat by getting strong in direct proportion to their anatomically proper share of the work in the movement, as determined by the mechanics of the movement itself. This fact is often overlooked when considering anterior cruciate tears and their relationship to the conditioning program. The ACL stabilizes the knee: it prevents the tibia from sliding forward relative to the femur. As we have already seen, so does the hamstring group of muscles. Underdeveloped, weak hamstrings thus play a role in ACL injuries, and full squats work the hamstrings while partial squats do not. In the same way the hamstrings protect the knee during a full squat, hamstrings that are stronger due to full squats can protect the ACL during the activities that we are squatting to condition for. In fact, athletes who are missing an ACL can safely squat heavy weights, because the ACL is under no stress in a correctly performed full squat (fig below).
Another problem with partial squats is the fact that very heavy loads may be moved, due to the short range of motion and the greater mechanical efficiency of the quarter squat position. This predisposes the trainee to back injuries as a result of the extreme spinal loading that results from putting a weight on his back that is possibly in excess of three times the weight that can be safely handled in a correct deep squat. A lot of football coaches are fond of partial squats, since it allows them to claim that their 17 year-old linemen are all squatting 600 lbs. Your interest is in getting strong (at least it should be), not in playing meaningless games with numbers. If it’s too heavy to squat below parallel, it’s too heavy to have on your back.
Olympic weightlifters provide a perfect illustration of the safety and benefits of the full squat. As of the 2004 Olympics 167 of the 192 countries in the world compete in Olympic Weightlifting. More than 10,000 individuals compete annually in IWF (International Weightlifting Federation) events alone, and the number of participants in total from the 167 countries would be staggering, likely on the order of 2 to 5 million (China alone boasts over 1 million lifters). All over the world, weightlifters squat way below parallel safely, most often using some form of the exercise, either back squats or front squats, every day. That is correct: they squat way below parallel every training day, and most programs call for six days per week.
Isn’t it fascinating that they are both strong and not under the care of an orthopedic surgeon? There is simply no other exercise, and certainly no machine, that produces the level of central nervous system activity, improved balance and coordination, skeletal loading and bone density enhancement, muscular stimulation and growth, connective tissue stress and strength, psychological demand and toughness, and overall systemic conditioning than the correctly performed full squat. In the absence of an injury that prevents their being performed at all, everyone that lifts weights should learn to squat, correctly.
Forces on the knee in the squat. The hamstrings and adductors exert a posterior tension on the tibia, and the net effect of the anterior quadriceps tendon insertion is an anterior force against the tibial plateau. With sufficient depth, anterior and posterior forces on the knee are balanced. The anterior and posterior forces on the knee are balanced. The anterior and posterior cruciate ligaments stabilise anterior and posterior movement of the distal femur relative to the tibial plateau. In the correct squat, these ligaments have very little to do.
Article is an excerpt from the chapter ‘The Squat’ – Starting Strength 2nd Edition – Mark Rippetoe & Len Kilgore
Anyone that exercises whether it be weightlifting or running or even if you don’t exercise and work in an office or typically have to sit at work all day – You need to start using a foam roller. If you struggle with posture or tight muscles or are just looking to improve your flexibility/mobility, buy yourself a roller! – They are cheap and easy to use and far more effective than stretching, they will alleviate typically tight and/or sore areas like lower back, hips or shoulder pain with simple easy to learn techniques as detailed below (article/guide originally posted on T-Nation)
Feel Better for 10 Bucks
Self-myofascial release: no doctor required!
by Eric Cressey and Mike Robertson
Ten bucks doesn’t buy much nowadays. You could pick up a day pass at some commercial gym, or pull off the co-pay on a visit to the chiropractor. If you’re lucky, you might even be able to swing a mediocre Russian mail order bride.
Or, you could just go the safe route with your $10, take our advice, and receive a lifetime of relief from the annoying tightness so many athletes and weekend warriors feel from incessantly beating on their bodies. Don’t worry, this isn’t an infomercial. We just want you to pick up a foam roller for self-myofascial release and deep tissue massage.
How does it work?
Self-myofascial release (SMR) on a foam roller is possible thanks to the principle known as autogenic inhibition. You’ve likely heard of the Golgi Tendon Organ (GTO) at some point in your training career. The GTO is a mechanoreceptor found at the muscle-tendon junction; it’s highly sensitive to changes in tension in the muscle.
When tension increases to the point of high risk of injury (i.e. tendon rupture), the GTO stimulates muscle spindles to relax the muscle in question. This reflex relaxation is autogenic inhibition. The GTO isn’t only useful in protecting us from injuries, but it also plays a role in making proprioceptive neuromuscular facilitation (PNF) stretching techniques highly effective.
The muscle contraction that precedes the passive stretch stimulates the GTO, which in turn causes relaxation that facilitates this passive stretch and allows for greater range of motion. With foam rolling, you can simulate this muscle tension, thus causing the GTO to relax the muscle. Essentially, you get many of the benefits of stretching and then some.
It’s also fairly well accepted that muscles need to not only be strong, but pliable as well. Regardless of whether you’re a bodybuilder, strength athlete, or ordinary weekend warrior, it’s important to have strength and optimal function through a full range of motion. While stretching will improve the length of the muscle, SMR and massage work to adjust the tone of the muscle. Performing one while ignoring the other is like reading T-Nation but never actually lifting weights to put the info to good use.
What’s SMR good for?
Traditional stretching techniques simply cause transient increases in muscle length (assuming that we don’t exceed the “point of no return” on the stress-strain curve, which will lead to unwanted deformities). SMR on the foam roller, on the other hand, offers these benefits and breakdown of soft tissue adhesions and scar tissue.
One mustn’t look any further than the overwhelmingly positive results numerous individuals have had with Active Release Techniques (ART) to recognize the value of eliminating adhesions and scar tissue. Unfortunately, from both a financial and convenience standpoint, we can’t all expect to get ART done on a frequent basis.
SMR on the foam roller offers an effective, inexpensive, and convenient way to both reduce adhesion and scar tissue accumulation and eliminate what’s already present on a daily basis. Just note that like stretching, foam rolling doesn’t yield marked improvements overnight; you’ll need to be diligent and stick with it (although you’ll definitely notice acute benefits).
Those of you who have been following our Neanderthal No More series will definitely be interested in the valuable role foam rollers can play in correcting postural afflictions. Get to work on those tight muscles and you’ll definitely see appreciable returns on your efforts!
So let’s get started!
What you need to get:
1) 6″ foam roller (either the 1′ long or 3′ long version)
2) Marvin Gaye’s “Sexual Healing” CD
3) A leopard-skin thong
4) Two quarts of baby oil to lube yourself up
Note: If you thought we were really serious on numbers two through four, you need to get your mind out of the gutter and find a new favorite website!
These techniques are actually very simple to learn. Basically, you just use your body weight to sandwich the roller between the soft tissue to be released and the floor. Roll at a slow pace and actually stop and bear down on the most tender spots (“hot spots”). Once the pain in these spots diminishes, roll the other areas.
In order to increase the pressure on the soft tissue, simply apply more of your body weight to the roller. The simplest way to do this is by either moving from working both legs at once to one leg, or by “stacking” one of your legs on top of the other to increase the tension.
As you get more comfortable with SMR, you’ll really want to be bearing down on the roller with most (if not all) of your body weight. As with almost anything in the training world, there’s considerable room for experimentation, so you’ll definitely want to play around with the roller to see what works best for you. Be careful to avoid bony prominences, though. (Insert your own joke here.)
One other technique we’ve found to be beneficial is to work from the proximal (nearest the center of the body) to the distal (away from the center of the body) attachment of the muscle. For instance, instead of working your quadriceps from top to bottom all in one shot, shorten your stroke a little bit. Work the top half first, and after it has loosened up, move on to the bottom half.
This is an important strategy because as you get closer to the distal muscle-tendon junction, there’s a concomitant increase in tension. By working the top half first, you decrease the ensuing tension at the bottom, essentially taking care of the problem in advance.
Note: Those with circulatory problems and chronic pain diseases (e.g. fibromyalgia) should NOT use foam rollers.
Demonstrations and Descriptions
Hamstrings: You’ll want to try these with the feet turned in, out, and pointing straight ahead to completely work the entire hamstring complex. Balance on your hands with your hamstrings resting on the roller, then roll from the base of the glutes to the knee. To increase loading, you can stack one leg on top of the other.
Hip Flexors: Balance on your forearms with the top of one thigh on the roller. Roll from the upper thigh into the hip. Try this with the femur both internally and externally rotated. To do so, just shift the position of the contralateral pelvis. (In the photo, Mike would want to lift his right hip to externally rotate the left femur).
Tensor Fascia Latae and Iliotibial Band: These are a little tricky, so we’ve included pictures from two different angles. Without a doubt, this one will be the most painful for most of you.
In the starting position, you’ll be lying on your side with the roller positioned just below your pelvis. From here, you’ll want to roll all the way down the lateral aspect of your thigh until you reach the knee. Stack the opposite leg on top to increase loading.
Adductors: Balance on your forearms with the top of one of your inner thighs resting on the roller. From this position, roll all the way down to the adductor tubercle (just above the medial aspect of the knee) to get the distal attachments. You’ll even get a little vastus medialis work in while you’re there. Watch out for your twig and berries on this one, though!
Quadriceps: This one is quite similar to the hip flexor version; you’re just rolling further down on the thigh. You can perform this roll with either one or two legs on the roller.
Gluteus Medius and Piriformis: Lie on your side with the “meaty” part of your lateral glutes (just posterior to the head of the femur) resting on the roller. Balance on one elbow with the same side leg on the ground and roll that lateral aspect of your glutes from top to bottom.
Gluteus Maximus: Set up like you’re going to roll your hamstrings, but sit on the roller instead. Roll your rump. Enough said.
Calves: This, too, is similar in positioning to the hamstrings roll; you’re just rolling knee to ankle. Try this with the toes up (dorsiflexion) and down (plantarflexion). Stack one leg on top of the other to increase loading.
Tibialis Anterior: This is just like the quad roll, but you’re working on your shins instead.
Peroneals: This one is similar to the TFL/ITB roll; we’re just working on the lower leg now. Roll along the lateral aspect of the lower leg from the knee to the ankle.
Thoracolumbar Fascia: With your arms folded across your chest, lie supine with the roller positioned under your midback. Elevate the glutes and roll from the base of the scapulae to the top of the pelvis. You’ll want to emphasize one side at a time with a slight lean to one side.
Thoracic Extensors, Middle and Lower Trapezius, Rhomboids: With your arms behind your head (not pulling on the neck), lie supine with roller positioned in the middle of your back; your glutes should be on the ground. Roll upward, reversing direction when you reach the level of the armpits. This is an excellent intervention for correcting kyphosis.
Latissimus Dorsi and Teres Major: Lie on your side with the same side arm overhead. The roller should be positioned at the attachment of the lat on the scapula in the starting position. You’ll want to roll toward the attachment on the humerus (roll toward the armpit).
Triceps: Start with your body in the same position as you would for the latissimus dorsi. Now, however, you’ll want to place the roller at the top of your triceps (near your armpit) and your noggin on top of your arm to increase the tension (and no, you don’t have to be that geeky kid from Jerry Maguire to know the human head weighs 8 pounds!)
Pectoralis Major and Anterior Deltoid: Lie prone with the roller positioned at an angle slightly to one side of the sternum; the arm on this side should be abducted to about 135° (halfway between completely overhead and where it would be at the completion of a lateral raise). Roll toward the humeral head (toward the armpit).
Hopefully, this article has been proof enough that SMR on the foam roller is an excellent adjunct to your training, diet, supplementation, and restoration efforts. And, even if it isn’t, we’re only talking about ten bucks here, people! For crying out loud, just look under the couch cushions for change and you’re halfway there!
Where do you buy one? Try Perform Better:
Pick one up and give it a shot. Your body will thank you for years to come!
About the Authors
Eric Cressey, BS, CSCS is currently pursuing a Master’s Degree in Kinesiology with a concentration in Exercise Science at the University of Connecticut. He graduated from the University of New England with a double major in Exercise Science and Sports and Fitness Management. Eric has experience in athletic performance, rehabilitation, and general conditioning settings. He can be contacted at firstname.lastname@example.org.