Stuart McGill's DVDs are helpful, but as the other reviewer emphasized, could have been far better produced. The sound is unclear, there's no real editing of the material, so we get a lot of extraneous and useless images, and the demonstrations could be more explicit. They are self-produced, self-published, and self-marketed by Prof. Stuart McGill and his little business outfit, "Backfitpro" in Waterloo, Ontario.I now regret having bought that DVD, which I find useless compared to the two McGill books I bought.In self-publishing, McGill goes the amateurish route, unwilling to hire professional assistance to give a polished look to his product. We can regret he didn't hire a team of expert video exercise professionals to give it the superb professional look that, for instance, Jane Fonda has always been careful to present. He should have taken as models the professional fitness DVDs of known instructors: Jane Fonda or Denise Austen, for example.It is true that Jane Fonda has always lived in a world of supreme quality, in men, in looks, in life, in books and DVDs. This world of top quality products is unknown to good lab professor McGill.Stuart McGill's scientific approach, based on his strong biomechanics background, is topnotch, but his self-made business products are on the amateurish side and do not render justice to the quality of his teachings.As great supports for the DVDs, do not hesitate to get his two books:1) LOW BACK DISORDERS, 2d ed., a first-class textbook on back injuries and their prevention. The best of its class and superbly published by Human Kinetics.Only in the very last chapter 13 does he consider "Advanced Exercises", those for high-performance workers and athletes, putting the accent on back exercises to be practiced only by athletes who already have established a solid base of fitness and overall strength.2) ULTIMATE BACK FITNESS AND PERFORMANCE, 5TH ED (2014), which picks up from the last chapter of "Low Back Disorders", amplifying its content, and gearing the book primarily to top performers in sports and athletic competitions. De facto this second book becomes a training manual for physical fitness fanatics concerned about their backs.The material of this fitness training manual is excellent, but its physical presentation suffers from the decision to self-produce and self-market it through the same in-house business outfit, "Backfitpro". It does not offer the kind of superlative quality of the textbook produced by Human Kinetics.Self-publishing of the DVDs and the "Ultimate Back Fitness" may be a little more financially rewarding (in the short run only) to Prof. Stuart McGill and his family, but the amateurish presentation of the products is already a considerable drawback to its success.And it renders a sheer disservice to all of Stuart McGill's students and followers, considering that these products are not as useful and effective as they could have been if produced by professionals.Similarly the distribution method selected prevents these interesting books and DVDs from reaching a huge market, that they surely would deserve.It is regrettable that these DVDs and the 5th edition of "Ultimate Back Fitness" are not available directly from Amazon, whereas "Low Back Disorders" is sold directly by Amazon.Tempted buyers should not fall victims of the scalpers who use the Amazon market place to extort exorbitant prices for the third edition of "Ultimate Back Fitness".The fourth edition is posted on Amazon as "Ultimate Back Fitness AND Performance 4th Ed", and simultaneously as "Ultimate Back Fitness & Performance 4th Ed", where "AND" has been replaced by "&". And you will not find it in the "Books" department, but in "All Departments".Note that the 5th edition (2014) is not yet available on Amazon, as McGill has preferred to sell it only directly through his publishing and marketing outfit, BACKFITPRO, where it is available for CAN$45.This way the new 5th edition (2014) does not compete with the 3d edition (2004) and the 4th edition (2009) still offered on Amazon.Both of McGill's books offer a much clearer presentation of the spotty instruction delivered in the DVDs, which I found on the whole too amateurish and lacking the polish and density of content that they should have. I would have never bought it if I had been aware of this amateurish character.Self-publishing is OK for minor works of secondary interest, but quality material should have the high quality presentation that only professional DVD production (such as used by Jane Fonda) and book publishers (such as superlative Human Kinetics) can offer.CONCLUSION:The asking price of $94 for the old version with 2 discs is simply OUTRAGEOUS, a brutal rip-off. "The Ultimate Back (DVD): Assessment and Therapeutic Exercise, SECOND EDITION (2012)", with 3 discs is sold directly by McGill's commercial outfit, BackFitPro, for CAN $64.If you're a professional therapist, get the damn thing and write it off to expenses.If you're just a fitness buff and athlete, don't waste your money, buy McGill's two books, preferably directly from him (as he is offering the lowest prices), and forget about the DVD.There's too much fluff and marketing spiel in these self-produced items.