What All Squatters Need To Know

written by Frederick C. Hatfield, Ph.D., MSS, International Sports Sciences Association

Editor’s Note: Dr. Fred Hatfield isn’t called "Dr. Squat" for nothing. In 1987, after 30 years of squatting, he performed a competitive squat of 1014 pounds. By his own estimate, over the previous ten years he had exceeded 800 pounds in the squat more than 1500 times. That’s roughly 500 squat workouts averaging three such monster squats per workout. When asked why he’d do such a thing to himself, he replied, "I KNEEded to!" To this day, his knees are fine.

Squats can be bad for your knees. Period. But they’re good for everything else.

So good, in fact, that you MUST do them. I don’t care if you’re a bodybuilder, a powerlifter or a ballerina. Ya gotta do them! Question is, how? The answer is, as safely as possible without losing any of the benefits! Sorta like drugs, no? The art and science of medicine dictates that while using drugs, you must minimize the risks while maximizing the benefits. If there’s one way to take your iron pill, then, it’s in large doses! That means SQUATTING!

In sports, knee problems are nigh unto a way of life, but squatting isn’t the primary culprit. Among bodybuilders who have knee problems, however, squatting is the only culprit. In both cases, squatting properly can reduce, prevent or ameliorate many, many of the common knee problems inherent in sports. That they will make you a better bodybuilder or athlete is an unquestioned fact.

Speaking of the world of medicine and the practitioners thereof, you’ll find precious few who have any real, first-hand knowledge of squatting technique or its effects (good and bad) on the knees. One who does is three-time California powerlifting champion Dr. Sal Arria, my fellow co-founder of the International Sports Sciences Association. He’s the guy right behind me in the photo of me squatting 1014 pounds. Dr. Arria, in the ISSA’s course text, Fitness: Complete Guide for personal fitness trainers, listed many common nee problems and ways to prevent them. I’ve drawn heavily from that text in writing this article. I also drew from several other sources (see references).


Keeping your knees healthy and asymptomatic begins with developing a functional understanding of how this unique joint is constructed (anatomy) and how it does and doesn't function (biomechanics).

The knee is a hinge-type joint, roughly equivalent to a door hinge, but with a little "twist" to lock it into full extension. Instead of a fixed axis (such as a door hinge has), however, it’s a complicated movement consisting of gliding and rotation in such a fashion that the articulating surfaces are always changing. Hence, the axis is always changing. That can lead to trouble, particularly during unweighted exercises such as leg extensions.

It’s almost a law that your quads and hammies should be of approximately equal strength in order to provide "balanced" development. Some experts claim that a ham-to-quad strength ratio of 1 to 1 reduces shear and hamstring pulls. At best, this is mere speculation. When I was a powerlifter, my hamstrings were close to twice or three times the strength of my quads. Most sprinters are much stronger in the mammie department too, because that’s what they all use! If you give attention to muscle balance, beware that speculation is rampant.

Seven different types of tissue comprise the knee -- bones, ligaments, tendons, muscles, synovial fluid (bursa), adipose tissue and articular cartilage.

Bone: The bony structures forming the knee joint are the femur, tibia, and the patella.

Ligaments: Fibrous connective tissue which connects bone to bone, providing stability and integrity to the joint. The knee’s ligaments are divided into two groups, eight interior and six external ligaments.

Muscle: We all have a clear idea as to what muscles are. Clearly, there are no muscles in the knee joint itself. The ones which act upon the knee joint are all external to the knee. They are listed below:


Despite the inherent problems with squatting, all of us have for years put up with them. We squat no matter what, because it has always been thought of as best to do so. That we've gotten by and made progress with the three conventional squatting techniques mentioned below is due in no small measure to the fact that squats are a necessary part of our training. It's what we do.

Powerlifting Squats (wide, intermediate or narrow stance): The distinguishing characteristic of this squatting technique is that the hip angle is acute and the knee is kept close to a right angle. The knees remain over the feet. This places the load on the gluteals and hamstrings, enabling greater loads to me moved. The danger is the shear placed on the lumbar spine, so great erector spinae strength must be developed prior to attempting this technique with heavy weights.

Olympic Squats (also called "High Bar Squats" or "Bodybuilding Squats"): Olympic lifters trained this way many years ago, and bodybuilders favor it because the brunt of the load is caried by the quads. Bodybuilders claim that squatting this way “prevents” getting overly-developed gluteals. The hip is at a right angle and the knees are acutely flexed, placing great shear on the knees.

Athlete’s Squats: If you’re going to squat for fitness or sports, and do not have a safety squat bar, this is the safest way to go. Please refer to the sidebar accompanying this article for a detailed description of the proper technique. Bear in mind that shear at both the knees and at the lumbar spine is still present, though far less than in the powerlifting or Olympic styles of squatting.


Here are a few leg exercises (including some techniques I’ve developed over the years). Some may provide both protection from and ways around knee injuries. Others, however, are merely alternatives to squatting, with little justification or with little in the way of added benefit beyond what squatting affords. Still others are downright dangerous and should be avoided.

Safety Squats: The "safety squat bar" (sometimes called the "Hatfield Bar") is, in my opinion, the safest method of squatting because the shear on knees and low back are reduced significantly. The accompanying sidebar compares safety squats with the conventional methods of squatting.

Leg Extensions and Leg Curls: These two exercises are favorites of bodybuilders and fitness enthusiasts. While they may be "OK" for them, they are decidedly useless for otherwise healthy athletes. Eliminate them from your training except during times when, due to injury, they're the only movements you can perform safely and pain-free. Further, most therapists nowadays recognize that unloaded movements such as the leg extension places great shear on the knee joint, and is potentially dangerous, particularly the lower half of the movement.

Lunge Squats: There are many variations to the squat movement. One extremely important one is the "lunge" squat. Lunge squats can be done to the left, right or forward, placing the weight on the lead leg. The quad muscles of the lead leg are targeted with both front and side lunges. Side lunges also target the groin muscles (especially the adductor gracilis of the opposite leg). Careful though! Advancing in a forward direction into the lunge position places tremendous shear on the knee joint! It’s best to lower into the position insterad of lunging into it.

Twisting Squats: From a front lunge position, you can "twist" to the opposite side of your lead leg while ascending from the lunge position. This is an exercise which I had originally developed for athletes like down-linemen or shot putters who are required to explode laterally while twisting upwards out of a lunge or squat position. Bodybuilders and all other athletes benefit too, in that fuller leg development is achieved in the sartorius and adductor muscles of the upper leg. "Twisting squats," as they're called, require a special harness to wear on your chest and shoulders to hold the short bar in place. DO NOT attempt to do twisting squats with a long bar, or with the bar placed on your shoulders! Loss of control in this exercise can mean groin, knee and low back injury. Also, remember that torque shear forces within the knee must be held to a minimum through careful, controlled movement.

Hack Squats and Leg Presses: Hack squat machines and leg press machines of all varieties come in handy if 1) you haven't learned how to do squats properly yet, 2) you don't have a safety squat bar, 3) you don't have a spotter to help you do squats, or 4) if your back is tired or injured and you can't do regular squats. At best, they're poor substitutes for conventional or safety squats, especially due to the fact that destructive shear forces in the knee can be as much as 30 percent higher than with conventional techniques. This caution also applies to Sissy Squats, Front Squats and Overhead Squats (also called snatch grip squats).

Smith Machine Squats: Assuming that the machine is bolted to the floor (most are not) and has a safety device (most do not), it’s a pretty safe alternative to conventional or safety squats. since he same technique rules apply to Smith squats as apply to safety squats. The effect is derived from the fact that you’re actually “leaning” against the bar, thereby minimizing shear forces in the lower back. However, shear on the knees is still considerable. Beware!

Partial Squats: Contrary to popular belief, squatting above the parallel position -- knees at approximately 90 degrees flexion -- is actually more dangerous that going to parallel or below. There are two reasons for this. When you look at the structure of the knee, you’ll note that at about 90 degrees flexion, the tibia’s sloped shape allows it to shear upwards and over the femur. This causes a lot of compressive force against the patella, and pulls forcefully against the posterior cruciate ligament. These potentially destructive forces become significantly less as you descend further into the squat postion, largely due to the fact that the tibia’s surface isn’t as sloped posteriorly, where it articulates with the femur. The second reason is that, because of better leverage while doing partials, you’re obliged to use a far heavier weight in order to gain any sort of adaptive overload on the muscles involved -- dangerous to the entire shoulder girdle, neck, low back and knees.

Heel or Block Squats: The practice of putting a block of wood nder your heels is widespread among bodybuilders in order to gain better isolation of the quads while squatting. The problem is that your knees go way out over your feet, placing great shear and compression on both the cartialge and ligaments of the knee. This allpies to Olympic or Athlete squats, but not to powerlifting squats where a conscious effort is made to keep your knees above your feet. As a powerlifter, I used 2 inch heel inserts in order to reduce the time it took me to get my hips back under the weight during the ascent. This practice gave me at least a 5 percent advantage in weight hoisted.


Two pieces of standard squatting gear -- your shoes and knee wraps -- should be carefully selected and used, not only to maximize both the short- and long-term health of your knees.

Shoes: Your shoes are literally where the rubber hits the road. Think of your shoes as the foundation of your leg training sessions. Wearing old or broken down fitness shoes for heavy squatting is like putting old, worn-out tires on a race car! There are several reasons to avoid training in your "tennies." First, most general purpose fitness shoes simply lack adequate longitudinal or transverse stability, and have little or no arch support for heavy lifting. As you squat, your feet may develop a tendency to pronate, or "cave in" toward the inner side. When this happens, the knees are also forced inward, leading to a constant strain on the medial collateral ligaments, excessive shear force on the meniscus, and improper patellar tracking, which in turn can lead to chondromalacia. If your feet tend to pronate anyway, or if you're prone to being"knock kneed" (and these two conditions are very often associated with one another), it becomes even more important to select good training shoes.

Another important reason for using specialized shoes for squatting is that they provide a deep and solid heel cup, which prevents the foot from rocking and rolling to the outside, causing great stress on the lateral collateral ligaments of your knees.

Finally, there is a difference between a shoe being worn out and being broken down. Even if your shoes look fine, they still may offer no arch or heel support at all, either because they never had any to start with, or because after months of use, the supports have compressed to the point to where they no longer function as they were intended. Think about it -- a tennis shoe is meant to support a 160 pound tennis player, NOT a 600 pound squat! Loads like these cause the shoe to break down without visual signs of wearing out.

Knee wraps have long been a mainstay for competitive powerlifters, and for good reason. When properly used, wraps can dramatically improve knee safety during heavy squatting. More important, however, is the fact that wraps give you at least a 5-10 percent increase in how much you can lift. But there’s a downside to using wraps also. Wearing them while squatting under 80-85 percent or so is counterproductive to providing adaptive overload to various tissues comprising the knee. Simply, the wrap absorbs the stress instead of the tissues, so they never get stronger. Guidelines for wearing knee wraps during squatting are as follows:

  1. Keeping your knees warm (wrapped loosely) improves blood flow and
  2. tissue elasticity
  3. If the weight you're using is greater than 80-85 percent of your maximum or
  4. If you have knee problems that require wearing wraps.

If you STILL insist on using them, go ahead and do so, but with the following points in mind. When buying knee wraps, opt for the ones that 1) weigh the most (more fabric equals greater protection, and 2) that stretch out to at least 19-20 feet in length (more times around the knee equals greater protection). Do NOT purchase wraps that are bulky, heavily elasticized and stretch out to under fifteen feet. Tightness from elasticity is NOT affording you any real support!

Here are the steps to go through when putting your wraps on:

Sit on a chair or bench. Begin with the wrap completely stretched and rolled up (this makes the process much easier than fighting to stretch the wrap as you go). With your leg straight, start applying the wrap below the knees, working upward. Wrapping from "in" to "out," (counterclockwise for the left leg, clockwise for the right -- this helps avoid improper patellar tracking), anchor the wrap by applying two layers below the knees, then move upward, overlapping each previous layer by one-half the width of the wrap. Apply the wrap tightly as you move past the knee, stopping somewhere on the lower third of the thigh (powerlifting rules allow 10 centimeters above the patella). Most of the wrap is wound around the leg just above the knee joint in order to "pin" the quadriceps tendon to the femur below -- better leverage. Tuck the end of the wrap under the previous layer to secure it. Repeat for the other leg.

An alternative more suitable for fitness and bodybuilding, perhaps, is to wrap tightly around the upper shin (where the patellar ligament attaches), then more loosely wound over the kneecap itself (this is important to avoid grinding the patella into the femoral condyle, creating a case of chondromalacia for yourself), then tightly wound over the lower quarter of the thigh.

The rationale for wrapping the knees prior to heavy squatting is that it reduced the pulling forces on the lower quadriceps and the quadriceps tendon at it's attachment to the patella. This translates to significantly reduced chances of avulsing (detaching) your quadriceps tendon or tearing your quads during heavy squatting. The chances of your patellar tendon avulsing from your tibia are a bit less, but nonetheless omnipresent.


Whenever you squat, hack squat, or leg press, your foot position is an important variable in determining not only the results you'll obtain from the exercise, but also the safety of your knee joints. Although each individual must determine their own best stance exercise per exercise (based on their own anatomical peculiarities such as height and leg length), the following variables must be taken into consideration:

1) The quadriceps muscles can contract more efficiently when the feet are pointing slightly outward . They should NEVER point straight ahead. If you squat with a very wide stance, your adductors tend to assist the quads. This can result in stress to the medial collateral ligament, abnormal cartilage loading, and improper patellar tracking.

2) During the decent phase of any type of squat, do not allow the knees to extend beyond your feet. The further your knees travel over your feet, the greater the shearing forces on the patellar tendon and ligament.

3) Make sure that your knees point in the same direction your feet are pointing during the descent and ascent. Because of weak quads, many lifters inadvertently turn their knees inward during the ascent, placing great stress on the medial ligaments of the knee.

4) Although many top bodybuilders advocate a very close stance for the purpose of isolating the outer quads, this is a myth, and it places you at risk, particularly since you’ll have to use a lot of back to execute the lift, or (if you use heels) place great shear and compression on the knees. The best way to squat is to put your feet in a position where they can generate the greatest opposing force to the weight ("the athletic postition"). Follow the squatting technique pointers presented in the sidebar accompanying this article.

5) Warm up thoroughly before squatting. Your muscles and other tissues of the knee joint LOVE warmth! Remember the analogy, cold taffy breaks, warm taffy doesn’t.

6) Maintain reasonable flexibility in the joints of your lower extremities and back. Many knee injuries can be traced back to poor position resulting from inflexibility.

7) Finally, be very careful in the exit out of the rack, and getting "set" in the squat stance. After lifting the weight off of the pins, you should take just one step backward and immediately assume your squatting stance. This takes time to master, but eventually all the minute adjustments can be pared down substantially. Once set in the stance, keep your feet "nailed down" for the duration of the set. Many people "fidget" with their feet and toes between reps which can cause a variety of problems ranging from a break in concentration to a loss of balance -- and attendant stress on your knees.


  1. The chance of leaning forward or rounding your back under heavy loads is always a problem; Falling off balance forward or backward also jeopardizes your safety during heavy squatting.
  2. Squatting with a straight bar, you're forced to use a load that you can handle in the weakest position. This results in using an inadequate amount of weight in the strongest position of the squatting motion.
  3. Your shoulder girdle, shoulders, wrists and elbows often take a beating holding the straight bar firmly in position; Discomfort to the back of the neck (typically at the 7th cervical vertebra) where the bar sits is a problem we all shrug off as part of the game
  4. Missing a squat attempt is something which happens to all of us from time to time, often with dire consequences; Not being able to squat because of the lack of competent spotters has been one of my personal gripes
  5. Individual anatomical peculiarities often make it difficult to assume the most efficient stance; Conventional squatting places the weight behind your body's midline. That caused you to lean or bend forward for balance
  6. Perhaps the most dangerous part of squatting is the need to take several steps backward to set up, and then return to the rack after squatting. This factor alone accounts for over 75 percent of all squatting-related injuries!

  1. Your hands are not holding the bar. Rounding, imbalance or leaning is avoided by exerting pressure against the power rack handles and thus maintaining a perfectly straight back throughout the entire squatting motion.
  2. Your hands can be used to help you through sticking points. This unique feature allows you to work with heavier weights in the ranges of movement where you are strongest and gives you help when you are weakest. You are exerting closer to your maximum effort through the entire range of motion.
  3. The padded yolk that the Safety Squat Bar is equipped with effectively eliminates neck and shoulder girdle discomfort. And the fact that you needn't use your hands to hold the bar on your shoulders eliminates wrist, shoulder and elbow discomfort.
  4. You can use your hands to avoid missing a squat attempt.
  5. With the Safety Squat Bar, the weight is distributed directly in line with your body's midline, This,together with your hands, you can “tailor” your technique to your body.
  6. Finally, because you are holding onto handles build onto the squat rack, you do not back up before squatting, and you are not obliged to walk back into the rack after squatting. This element alone has the potential of eliminating up to three quarters of all squatting-related injuries.




Chondromalacia patellae: Softening of the articular cartilage of the patella that is produced by osteoarthritic degeneration. Such cartilage is unsuited for the high compressive loads and frictional forces involved in squatting, and roughening of the underside of the kneecap is common. Tight quads are responsible for 80% of chondromalacia. Other causes include aging, repetitive overuse, and faulty biomechanics due to genetics.

Patellofemoral Pain Syndrome (PFPS): Exemplified by pain in front of patella, which intensifies during activity. Also, pain during extended sitting, and/or walking up stairs. PFPS is further characterized by crepitus (noise), without instability. PFPS is considered to be a tracking problem ofthe patella, caused by an imbalance between the medial and lateral quadriceps. The damage to the underside of the patella is not unlike uneven tread wear in a car that needs the tires rotated.

Unstable Knee Joint: Knee suddenly gives out. This is often caused by old injuries which have overstretched the knee ligaments.

Locked Knee: The usual cause of locked knees is a torn meniscus or a loose body within the joint capsule.

Swelling/Tightness: Nearly always indicates an internal injury. See physician immediately.

Crepitus: Noisy knees are no reason for concern, UNLESS accompanied by pain and/or swelling.

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