Dr. Squat: Rotator cuff, anterior delts, and in general, all 14 muscles spanning the shoulder girdle.
Igor: Please explain compensatory acceleration… . Dr. Squat: Pushing the weight as hard as possible every inch of the way. This effectively turns any weight into a far heavier weight, and every inch of evefry rep a max effort.
Igor: You also state that with explosive movements against resistance the Golgi tendon organ will be delayed in sending its stretch message to the brain. When this happens the brain sends a message to the contracting muscle to shut down. This response limits strength. So by delaying this message you are allowing your strength to increase. Louie Simmons recommends weights that are from 50%-60% of max. If I understood correctly for limit strength and explosive strength, you suggest that most of your time should be spent closer to the 85% (for powerlifters). You also say that staying close to 55% actually trains starting and reactive strength… So which percentage will benefit the powerlifters mostly?
Dr Squat: 55 percent (or thereabouts -- there aren't any holy numbers) can be moved fater than can 85 percent. Simple. The effects on your peripheral and central nervous systems (assuming you're using compensatory acceleration, and avoiding the sudden direction changes at the end points of a lift that cause tissue damage) is such that the defensive shut-down signal emanating from the Golgi tendon organ is blunted or pushed back a bit.
Igor: You’ve once mentioned some coaches schooled in the old Soviet approach to training separately refer to "reactive strength" or one's ability to switch from eccentric to concentric during the “stretch shortening cycle.”
It's often considered a third component of speed-strength. It is alternately called the “amortization” phase or the “transition” phase. It is the application of great muscle force being applied to “put the breaks on” the eccentric phase -- static contraction -- in preparation for the initiation of maximum fiber recruitment (starting strength). How can this component of speed-strength be trained?
Dr. Squat: Carefully, and at the end of a training cycle for a brief period...with plyometrics.
Igor: Thank you very much for the interview, Mr. Hatefiled!