Box squatting is the most effective method to produce a first-rate squat.  This is, in my opinion, the safest way to squat because you don't use as much weight as you would with a regular squat. 
          Let me say first that, no, they won't hurt your spine, you don't use1000 lbs. on a 25 inch tall box, you don't rock on the box, you don't touch and go, and there is no need to do regular power squats before a meet.  No knee wraps are worn nor are the straps of the suit pulled up. 
          By doing sets of 2 reps for at least 8 sets with short rest periods, you will get about a 200 lb. carryover to your regular squat.  Two of our lifters finished their lifting cycle before a meet with 8 sets of 2 reps with 505 lbs. off a slightly below parallel box, and both squatted 700 for a meet PR One was competing in the 242s and the other as a 275. Two years before, in his first meet, our 275 pounder squatted 465 - quite an improvement! 
          There are many advantages to box squatting.  One of the most important is recuperation.  You can train more often on a box than you can doing regular squats.  The original Westside boys (Culver City, CA) did them three times a week, which I feel is a bit extreme, but they paved the way for this type of training.  We do them for the squat part of our workout on Fridays and occasionally on Mondays to build hip and low back power for deadlifting.  The NBA's Utah Jazz do box squats for the same reason - recuperation. Greg Shepherd, their strength coach, is a former member of the Culver City gym. 
          The second reason is equally important.  It is generally accepted that you should keep your shins perpendicular to the floor when squatting.  With box squatting, you can go past this point (that is, an imaginary line drawn from your ankle to your knee will point toward your body), which places all the stress on the major squatting muscles- hips, glutes, lower back, and hamstrings.  This is a tremendous advantage- 
          Thirdly, you don't have to ask anyone if you were parallel.  Once you establish a below parallel height, all of your squats will be just that -below parallel.  I have seen it over and over.  As the weights get heavier, the squats get higher.  This can't happen with box squats. 
             
          If your hips are weak, use a below parallel box with a wide stance. If you need low back power, use a close stance, below parallel.  If your quads are weak, work on a parallel box.  If you have a sticking point about 2 inches above parallel, as is common, then work on a box that is 2 inches above parallel.  Our advanced squatters use all below parallel boxes.  This builds so much power out of the hole that there will be no sticking points. 
          As an added bonus, box squats will build the deadlift as well by overloading the hips and lower back muscles.  Your ability to explode off the floor will increase greatly.  One of our 275 pounders, Jerry Obradovich, put 50 lbs. on his dead lift in 3 months by doing extra box squats during that time period, going from 672 to 722 at the 1994 APF Junior Nationals.  Chuck Vogelpohl deadlifts only about once in 8 weeks yet pulls 793 in the 242s.  Chuck relies on wide box squats on a low, 12-inch box and does a lot of reverse hypers and chest-supported rows. 
          Now, how do you do a box squat?  They are performed just like regular squats.  Fill your abdomen with air, and push out against your belt.  Push your knees out as far as possible to the sides and with a tightly arched back, squat back, not down, until you completely sit on the box.  Every muscle is kept tight while on the box with the exception of the hip flexors.  By releasing and then contracting the hip flexors and arching the upper back, you will jump off the box, building tremendous starting strength.  Remember to sit back and down, not straight down.  Your hamstrings will be strengthened to a high degree, which is essential.  Many don't know this, but the hamstrings are hip extensors.  Some great squatters have large quads and some do not, but they all have large hamstrings where they tie into the glutes.  Remember to sit on the box completely and flex off. 
          Now, how do you know how much you can full squat if you box squat all the time?  Well, let's say you have squatted 600 lbs. in a meet and decided to box squat.  Let's say you can do 550 off a parallel box; that's a 50-lb. carry-over.  Now you are doing only box squats and you take a weight 4-6 weeks into the cycle.  You hit a 575 squat, a 25-lb.  jump on that particular box.  This will carry over to your 600 contest best.  So now expect a 625 at your next meet. 
          I recommend that you train with 65-82% of your box record on each particular box height that you use. Change box heights every 3-4 weeks.  Do not base the training weight on your full squat record!  Box squats are much harder than full squats!  Do 8-12 sets of 2 reps with 1 minute rest between sets. This is a tough workout!  The week that you reach 82%, reduce the sets to 6. Don't train with more than 82%. You can try a max the after you train with 82%.  If you are going to a meet, take a weight 2 weeks before the meet.  The week before the meet use 70% for 6-8 sets. 
          This type of squatting is hard work, but each rep shouldn't be hard.  Don't get psyched up to do your sets. We have found that 2 reps is ideal because any more may cause bicipital tendonitis and if you are doing 12 sets, you are doing 12 first reps per workout.  After all, the first rep is the most important one.  This will make your contest squat much better. Our most talented lifters will do best on their first rep and then tire quickly whereas our lower skilled people will do better after the first rep is completed because they use the first rep as a body awareness tool.  As they become more skilled, their first rep will be their best. 
          I know box squatting is not common, mostly because no one knows how do them.  After reading this or watching my squat tape you should be fully aware of the benefits.  Many great squatters have done box squats including Marv Phillips, Larry Kidney, Roger Estep, Matt Dimel, and of course George Fern, who did an 853 squat in track shorts in 1970.  If box squats didn't work, we wouldn't do them.  We have 20 lifters who have squatted over 700 lbs. in a meet including a 198 who has done 804. 1 hope this article clears up any misconceptions and leads to great success on the lifting platform.